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Collision detection - Game development | Collision detection
===================
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This is the **10th step** out of 16 of the Gamedev Phaser tutorial. You can find the source code as it should look after completing this lesson at Gamedev-Phaser-Content-Kit/demos/lesson10.html.
Now onto the next challenge — the collision detection between the ball and the bricks. Luckily enough we can use the physics engine to check collisions not only between single objects (like the ball and the paddle), but also between an object and the group.
Brick/Ball collision detection
------------------------------
The physics engine makes everything a lot easier — we just need to add two simple pieces of code. First, add a new line inside your `update()` function that checks for collision detection between ball and bricks, as shown below:
```js
function update() {
game.physics.arcade.collide(ball, paddle);
game.physics.arcade.collide(ball, bricks, ballHitBrick);
paddle.x = game.input.x || game.world.width \* 0.5;
}
```
The ball's position is calculated against the positions of all the bricks in the group. The third, optional parameter is the function executed when a collision occurs — `ballHitBrick()`. Create this new function as the bottom of your code, just before the closing `</script>` tag, as follows:
```js
function ballHitBrick(ball, brick) {
brick.kill();
}
```
And that's it! Reload your code and you should see the new collision detection working just as required.
Thanks to Phaser there are two parameters passed to the function — the first one is the ball, which we explicitly defined in the collide method, and the second one is the single brick from the bricks group that the ball is colliding with. Inside the function we remove the brick in question from the screen by running the `kill()` method on it.
You would expect to have to write a lot more calculations of your own to implement collision detection when using pure JavaScript. That's the beauty of using the framework — you can leave a lot of boring code to Phaser, and focus on the most fun and interesting parts of making a game.
Compare your code
-----------------
You can check the finished code for this lesson in the live demo below, and play with it to understand better how it works:
Next steps
----------
We can hit the bricks and remove them, which is a nice addition to the gameplay already. It would be even better to count the destroyed bricks increment the score as a result.
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Initialize the framework - Game development | Initialize the framework
========================
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This is the first of 16 tutorials to learn how to use Gamedev Phaser. After completing this tutorial you can find the source code for this section at Gamedev-Phaser-Content-Kit/demos/lesson01.html.
Before we can start writing the game's functionality, we need to create a basic structure to render the game inside. This can be done using HTML — the Phaser framework will generate the required `<canvas>` element.
The game's HTML
---------------
The HTML document structure is quite simple, as the game will be rendered entirely on the `<canvas>` element generated by the framework. Using your favorite text editor, create a new HTML document, save it as `index.html`, in a sensible location, and add the following code to it:
```html
<!doctype html>
<html lang="en-US">
<head>
<meta charset="utf-8" />
<title>Gamedev Phaser Workshop - lesson 01: Initialize the framework</title>
<style>
\* {
padding: 0;
margin: 0;
}
</style>
<script src="js/phaser.min.js"></script>
</head>
<body>
<script>
const game = new Phaser.Game(480, 320, Phaser.CANVAS, null, {
preload,
create,
update,
});
function preload() {}
function create() {}
function update() {}
</script>
</body>
</html>
```
Downloading the Phaser code
---------------------------
Next, we need to go through the process of downloading the Phaser source code and applying it to our HTML document. This tutorial uses Phaser V2 — it won't work with the current version on Phaser (V3). The V2 library is still available on the Phaser download page, below the links for the V3 download.
1. Go to the Phaser download page.
2. Choose an option that suits you best — we recommend the *min.js* option as it keeps the source code smaller, and you are unlikely to go through the source code anyway. **Please make sure to use Phaser version 2 as that's what this tutorial was written for.**
3. Save the Phaser code inside a `/js` directory in the same location as your `index.html` file.
4. Update the `src` value of the first `<script>` element as shown above.
Walking through what we have so far
-----------------------------------
At this point we have a `charset` defined, `<title>` and some basic CSS in the header to reset the default `margin` and `padding`. We also have a `<script>` element to apply the Phaser source code to the page. The body contains a second `<script>` element, where we will write the JavaScript code to render the game and control it.
The `<canvas>` element is generated automatically by the framework. We are initializing it by creating a new `Phaser.Game` object and assigning it to the game variable. The parameters are:
* The width and height to set the `<canvas>` to.
* The rendering method. The three options are `AUTO`, `CANVAS` and `WEBGL`. We can set one of the latter two explicitly or use `AUTO` to let Phaser decide which one to use. It usually uses WebGL if available in the browser, falling back to Canvas 2D if not.
* The `id` of the `<canvas>` to use for rendering if one already exists on the page (we've specified null because we want Phaser to create its own.)
* The names to use for Phaser's three key functions that load and start the game, and update the game loop on every frame; we will use the same names to keep it clean.
+ `preload` takes care of preloading the assets
+ `create` is executed once when everything is loaded and ready
+ `update` is executed on every frame.
Compare your code
-----------------
Here's the full source code of the first lesson, running live in a JSFiddle:
Next steps
----------
Now we've set up the basic HTML and learned a bit about Phaser initialization, let's continue to the second lesson and learn about scaling.
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Move the ball - Game development | Move the ball
=============
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This is the **4th step** out of 16 of the Gamedev Phaser tutorial. You can find the source code as it should look after completing this lesson at Gamedev-Phaser-Content-Kit/demos/lesson04.html.
We have our blue ball printed on screen, but it's doing nothing — It would be cool to make it move somehow. This article covers how to do just that.
Updating the ball's position on each frame
------------------------------------------
Remember the `update()` function and its definition? The code inside it is executed on every frame, so it's a perfect place to put the code that will update the ball's position on screen. Add the following new lines of the code inside `update()`, as shown:
```js
function update() {
ball.x += 1;
ball.y += 1;
}
```
The code above adds 1 to the `x` and `y` properties representing the ball coordinates on the canvas, on each frame. Reload index.html and you should see the ball rolling across the screen.
Compare your code
-----------------
You can check the finished code for this lesson in the live demo below, and play with it to understand better how it works:
Next steps
----------
The next step is to add some basic collision detection, so our ball can bounce off the walls. This would take several lines of code — a significantly more complex step than we have seen so far, especially if we want to add paddle and brick collisions too — but fortunately Phaser allows us to do this much more easily than if we wanted to use pure JavaScript.
In any case, before we do all that we will first introduce Phaser's physics engines, and do some setup work.
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Bounce off the walls - Game development | Bounce off the walls
====================
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This is the **6th step** out of 16 of the Gamedev Phaser tutorial. You can find the source code as it should look after completing this lesson at Gamedev-Phaser-Content-Kit/demos/lesson06.html.
Now that physics have been introduced, we can start implementing collision detection into the game — first we'll look at the walls.
Bouncing off the world boundaries
---------------------------------
The easiest way to get our ball bouncing off the walls is to tell the framework that we want to treat the boundaries of the `<canvas>` element as walls and not let the ball move past them. In Phaser this can be easily accomplished using the `collideWorldsBound` property. Add this line right after the existing `game.physics.enable()` method call:
```js
ball.body.collideWorldBounds = true;
```
Now the ball will stop at the edge of the screen instead of disappearing, but it doesn't bounce. To make this occur we have to set its bounciness. Add the following line below the previous one:
```js
ball.body.bounce.set(1);
```
Try reloading index.html again — now you should see the ball bouncing off all the walls and moving inside the canvas area.
Compare your code
-----------------
You can check the finished code for this lesson in the live demo below, and play with it to understand better how it works:
Next steps
----------
This is starting to look more like a game now, but we can't control it in any way — it's high time we introduced the player paddle and controls.
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Randomizing gameplay - Game development | Randomizing gameplay
====================
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This is the **16th step** out of 16 of the Gamedev Phaser tutorial. You can find the source code as it should look after completing this lesson at Gamedev-Phaser-Content-Kit/demos/lesson16.html.
Our game appears to be completed, but if you look close enough you'll notice that the ball is bouncing off the paddle at the same angle throughout the whole game. This means that every game is quite similar. To fix this and improve playability we should make the rebound angles more random, and in this article we'll look at how.
Making rebounds more random
---------------------------
We can change the ball's velocity depending on the exact spot it hits the paddle, by modifying the `x` velocity each time the `ballHitPaddle()` function is run using a line along the lines of the below. Add this new line to your code now, and try it out.
```js
function ballHitPaddle(ball, paddle) {
ball.animations.play("wobble");
ball.body.velocity.x = -5 \* (paddle.x - ball.x);
}
```
It's a little bit of magic — the new velocity is higher, the larger the distance between the center of the paddle and the place where the ball hits it. Also, the direction (left or right) is determined by that value — if the ball hits the left side of the paddle it will bounce left, whereas hitting the right side will bounce it to the right. It ended up that way because of a little bit of experimentation with the given values, you can do your own experimentation and see what happens. It's not completely random of course, but it does make the gameplay a bit more unpredictable and therefore more interesting.
Compare your code
-----------------
You can check the finished code for this lesson in the live demo below, and play with it to understand better how it works:
Summary
-------
You've finished all the lessons — congratulations! By this point you would have learnt the basics of Phaser and the logic behind simple 2D games.
### Exercises to follow
You can do a lot more in the game — add whatever you feel would be best to make it more fun and interesting. It's a basic intro scratching the surface of the countless helpful methods that Phaser provides. Below are some suggestions as to how you could expand our little game, to get you started:
* Add a second ball or paddle.
* Change the color of the background on every hit.
* Change the images and use your own.
* Grant extra bonus points if bricks are destroyed rapidly, several-in-a-row (or other bonuses of your choosing.)
* Create levels with different brick layouts.
Be sure to check the ever-growing list of examples and the official documentation, and visit the HTML5 Gamedevs forums if you ever need any help.
You could also go back to this tutorial series' index page.
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Build the brick field - Game development | Build the brick field
=====================
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This is the **9th step** out of 16 of the Gamedev Phaser tutorial. You can find the source code as it should look after completing this lesson at Gamedev-Phaser-Content-Kit/demos/lesson09.html.
Building the brick field is a little bit more complicated than adding a single object to the screen, although It's still easier with Phaser than in pure JavaScript. Let's explore how to create a group of bricks and print them on screen using a loop.
Defining new variables
----------------------
First, let's define the needed variables — add the following below your previous variable definitions:
```js
let bricks;
let newBrick;
let brickInfo;
```
The `bricks` variable will be used to create a group, `newBrick` will be a new object added to the group on every iteration of the loop, and `brickInfo` will store all the data we need.
Rendering the brick image
-------------------------
Next, let's load the image of the brick — add the following `load.image()` call just below the others:
```js
function preload() {
// …
game.load.image("brick", "img/brick.png");
}
```
You also need to grab the brick image from GitHub and save it in your `/img` directory.
Drawing the bricks
------------------
We will place all the code for drawing the bricks inside an `initBricks` function to keep it separated from the rest of the code. Add a call to `initBricks` at the end of the `create()` function:
```js
function create() {
// …
initBricks();
}
```
Now onto the function itself. Add the `initBricks()` function at the end of our games code, just before the closing </script> tag, as shown below. To begin with we've included the `brickInfo` object, as this will come in handy very soon:
```js
function initBricks() {
brickInfo = {
width: 50,
height: 20,
count: {
row: 3,
col: 7,
},
offset: {
top: 50,
left: 60,
},
padding: 10,
};
}
```
This `brickInfo` object will hold all the information we need: the width and height of a single brick, the number of rows and columns of bricks we will see on screen, the top and left offset (the location on the canvas where we shall start to draw the bricks) and the padding between each row and column of bricks.
Now, let's start creating the bricks themselves — add an empty group first to contain the bricks, by adding the following line at the bottom of the `initBricks()` function:
```js
bricks = game.add.group();
```
We can loop through the rows and columns to create new brick on each iteration — add the following nested loop below the previous line of code:
```js
for (let c = 0; c < brickInfo.count.col; c++) {
for (let r = 0; r < brickInfo.count.row; r++) {
// create new brick and add it to the group
}
}
```
This way we will create the exact number of bricks we need and have them all contained in a group. Now we need to add some code inside the nested loop structure to draw each brick. Fill in the contents as shown below:
```js
for (let c = 0; c < brickInfo.count.col; c++) {
for (let r = 0; r < brickInfo.count.row; r++) {
let brickX = 0;
let brickY = 0;
newBrick = game.add.sprite(brickX, brickY, "brick");
game.physics.enable(newBrick, Phaser.Physics.ARCADE);
newBrick.body.immovable = true;
newBrick.anchor.set(0.5);
bricks.add(newBrick);
}
}
```
Here we're looping through the rows and columns to create the new bricks and place them on the screen. The newly created brick is enabled for the Arcade physics engine, it's body is set to be immovable (so it won't move when hit by the ball), and we're also setting the anchor to be in the middle and adding the brick to the group.
The problem currently is that we're painting all the bricks in one place, at coordinates (0,0). What we need to do is draw each brick at its own x and y position. Update the `brickX` and `brickY` lines as follows:
```js
const brickX =
c \* (brickInfo.width + brickInfo.padding) + brickInfo.offset.left;
const brickY =
r \* (brickInfo.height + brickInfo.padding) + brickInfo.offset.top;
```
Each `brickX` position is worked out as `brickInfo.width` plus `brickInfo.padding`, multiplied by the column number, `c`, plus the `brickInfo.offset.left`; the logic for the `brickY` is identical except that it uses the values for row number, `r`, `brickInfo.height`, and `brickInfo.offset.top`. Now every single brick can be placed in its correct place, with padding between each brick, and drawn at an offset from the left and top Canvas edges.
Checking the initBricks() code
------------------------------
Here is the complete code for the `initBricks()` function:
```js
function initBricks() {
brickInfo = {
width: 50,
height: 20,
count: {
row: 3,
col: 7,
},
offset: {
top: 50,
left: 60,
},
padding: 10,
};
bricks = game.add.group();
for (let c = 0; c < brickInfo.count.col; c++) {
for (let r = 0; r < brickInfo.count.row; r++) {
const brickX =
c \* (brickInfo.width + brickInfo.padding) + brickInfo.offset.left;
const brickY =
r \* (brickInfo.height + brickInfo.padding) + brickInfo.offset.top;
newBrick = game.add.sprite(brickX, brickY, "brick");
game.physics.enable(newBrick, Phaser.Physics.ARCADE);
newBrick.body.immovable = true;
newBrick.anchor.set(0.5);
bricks.add(newBrick);
}
}
}
```
If you reload `index.html` at this point, you should see the bricks printed on screen, at an even distance from one another.
Compare your code
-----------------
You can check the finished code for this lesson in the live demo below, and play with it to understand better how it works:
Next steps
----------
Something is missing though. The ball goes through the bricks without stopping — we need proper collision detection.
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Game over - Game development | Game over
=========
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This is the **8th step** out of 16 of the Gamedev Phaser tutorial. You can find the source code as it should look after completing this lesson at Gamedev-Phaser-Content-Kit/demos/lesson08.html.
To make the game more interesting we can introduce the ability to lose — if you don't hit the ball before it reaches the bottom edge of the screen it will be game over.
How to lose
-----------
To provide the ability to lose, we will disable the ball's collision with the bottom edge of the screen. Add the code below inside the `create()` function; just after you define the ball's attributes is fine:
```js
game.physics.arcade.checkCollision.down = false;
```
This will make the three walls (top, left and right) bounce the ball back, but the fourth (bottom) will disappear, letting the ball fall off the screen if the paddle misses it. We need a way to detect this and act accordingly. Add the following lines just below the previous new one:
```js
ball.checkWorldBounds = true;
ball.events.onOutOfBounds.add(() => {
alert("Game over!");
location.reload();
}, this);
```
Adding those lines will make the ball check the world (in our case canvas) bounds and execute the function bound to the `onOutOfBounds` event. When you click on the resulting alert, the page will be reloaded so you can play again.
Compare your code
-----------------
You can check the finished code for this lesson in the live demo below, and play with it to understand better how it works:
Next steps
----------
Now the basic gameplay is in place let's make it more interesting by introducing bricks to smash — it's time to build the brick field.
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Physics - Game development | Physics
=======
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This is the **5th step** out of 16 of the Gamedev Phaser tutorial. You can find the source code as it should look after completing this lesson at Gamedev-Phaser-Content-Kit/demos/lesson05.html.
For proper collision detection between objects in our game we will need to have physics; this article introduces you to what's available in Phaser, as well as demonstrating a typical simple setup.
Adding physics
--------------
Phaser is bundled with three different physics engines — Arcade Physics, P2 and Ninja Physics — with a fourth option, Box2D, being available as a commercial plugin. For simple games like ours, we can use the Arcade Physics engine. We don't need any heavy geometry calculations — after all it's just a ball bouncing off walls and bricks.
First, let's initialize the Arcade Physics engine in our game. Add the `physics.startSystem()` method at the beginning of the `create` function (make it the first line inside the function), as shown below:
```js
game.physics.startSystem(Phaser.Physics.ARCADE);
```
Next, we need to enable our ball for the physics system — Phaser object physics is not enabled by default. Add the following line at the bottom of the `create()` function:
```js
game.physics.enable(ball, Phaser.Physics.ARCADE);
```
Next, if we want to move our ball on the screen, we can set `velocity` on its `body`. Add the following line, again at the bottom of `create()`:
```js
ball.body.velocity.set(150, 150);
```
Removing our previous update instructions
-----------------------------------------
Remember to remove our old method of adding values to `x` and `y` from the `update()` function:
```js
function update() {
ball.x += 1;
ball.y += 1;
}
```
we are now handling this properly, with a physics engine.
Final code check
----------------
The latest code should look like this:
```js
let ball;
function preload() {
game.scale.scaleMode = Phaser.ScaleManager.SHOW\_ALL;
game.scale.pageAlignHorizontally = true;
game.scale.pageAlignVertically = true;
game.stage.backgroundColor = "#eee";
game.load.image("ball", "img/ball.png");
}
function create() {
game.physics.startSystem(Phaser.Physics.ARCADE);
ball = game.add.sprite(50, 50, "ball");
game.physics.enable(ball, Phaser.Physics.ARCADE);
ball.body.velocity.set(150, 150);
}
function update() {}
```
Try reloading `index.html` again — The ball should now be moving constantly in the given direction. At the moment, the physics engine has gravity and friction set to zero. Adding gravity would result in the ball falling down while friction would eventually stop the ball.
Fun with physics
----------------
You can do much more with physics, for example by adding `ball.body.gravity.y = 100;` you will set the vertical gravity of the ball. As a result it will be launched upwards, but then fall due to the effects of gravity pulling it down.
This kind of functionality is just the tip of the iceberg — there are various functions and variables that can help you manipulate the physics objects. Check out the official physics documentation and see the huge collection of examples using the Arcade and P2 physics systems.
Compare your code
-----------------
You can check the finished code for this lesson in the live demo below, and play with it to understand better how it works:
Next steps
----------
Now we can move to the next lesson and see how to make the ball bounce off the walls.
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Buttons - Game development | Buttons
=======
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This is the **15th step** out of 16 of the Gamedev Phaser tutorial. You can find the source code as it should look after completing this lesson at Gamedev-Phaser-Content-Kit/demos/lesson15.html.
Instead of starting the game right away we can leave that decision to the player by adding a Start button they can press. Let's investigate how to do that.
New variables
-------------
We will need a variable to store a boolean value representing whether the game is currently being played or not, and another one to represent our button. Add these lines below your other variable definitions:
```js
let playing = false;
let startButton;
```
Loading the button spritesheet
------------------------------
We can load the button spritesheet the same way we loaded the ball's wobble animation. Add the following to the bottom of the `preload()` function:
```js
game.load.spritesheet("button", "img/button.png", 120, 40);
```
A single button frame is 120 pixels wide and 40 pixels high.
You also need to grab the button spritesheet from GitHub, and save it in your `/img` directory.
Adding the button to the game
-----------------------------
Adding the new button to the game is done by using the `add.button` method. Add the following lines to the bottom of your `create()` function:
```js
startButton = game.add.button(
game.world.width \* 0.5,
game.world.height \* 0.5,
"button",
startGame,
this,
1,
0,
2,
);
startButton.anchor.set(0.5);
```
The `button()` method's parameters are as follows:
* The button's x and y coordinates
* The name of the graphic asset to be displayed for the button
* A callback function that will be executed when the button is pressed
* A reference to `this` to specify the execution context
* The frames that will be used for the *over*, *out* and *down* events.
**Note:** The over event is the same as hover, out is when the pointer moves out of the button and down is when the button is pressed.
Now we need to define the `startGame()` function referenced in the code above:
```js
function startGame() {
startButton.destroy();
ball.body.velocity.set(150, -150);
playing = true;
}
```
When the button is pressed, we remove the button, sets the ball's initial velocity and set the `playing` variable to `true`.
Finally for this section, go back into your `create()` function, find the `ball.body.velocity.set(150, -150);` line, and remove it. You only want the ball to move when the button is pressed, not before!
Keeping the paddle still before the game starts
-----------------------------------------------
It works as expected, but we can still move the paddle when the game hasn't started yet, which looks a bit silly. To stop this, we can take advantage of the `playing` variable and make the paddle movable only when the game has started. To do that, adjust the `update()` function like so:
```js
function update() {
game.physics.arcade.collide(ball, paddle, ballHitPaddle);
game.physics.arcade.collide(ball, bricks, ballHitBrick);
if (playing) {
paddle.x = game.input.x || game.world.width \* 0.5;
}
}
```
That way the paddle is immovable after everything is loaded and prepared, but before the start of the actual game.
Compare your code
-----------------
You can check the finished code for this lesson in the live demo below, and play with it to understand better how it works:
Next steps
----------
The last thing we will do in this article series is make the gameplay even more interesting by adding some randomization to the way the ball bounces off the paddle.
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Load the assets and print them on screen - Game development | Load the assets and print them on screen
========================================
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This is the **3rd step** out of 16 in the Gamedev Phaser tutorial. You can find the source code as it should look after completing this lesson at Gamedev-Phaser-Content-Kit/demos/lesson03.html.
Our game will feature a ball rolling around the screen, bouncing off a paddle, and destroying bricks to earn points — familiar, huh? In this article we'll look at how to add sprites into our gameworld.
Having a ball
-------------
Let's start by creating a JavaScript variable to represent our ball. Add the following line between the game initialization code (our `const game` block) and the `preload()` function:
```js
let ball;
```
**Note:** For the sake of this tutorial, we will use global variables. The purpose of the tutorial is to teach Phaser-specific approaches to game development rather than dwelling on subjective best approaches.
Loading the ball sprite
-----------------------
Loading images and printing them on our canvas is a lot easier using Phaser than using pure JavaScript. To load the asset, we will use the `game` object created by Phaser, executing its `load.image()` method. Add the following new line just inside the `preload()` function, at the bottom:
```js
function preload() {
// …
game.load.image("ball", "img/ball.png");
}
```
The first parameter we want to give the asset is the name that will be used across our game code — for example, in our `ball` variable name — so we need to make sure it is the same. The second parameter is the relative path to the graphic asset. In our case, we will load the image for our ball. (Note that the file name does not also have to be the same, but we'd recommend it, as it makes everything easier to follow.)
Of course, to load the image, it must be available in our code directory. Grab the ball image from GitHub, and save it inside an `/img` directory in the same place as your `index.html` file.
Now, to show it on the screen we will use another Phaser method called `add.sprite()`; add the following new code line inside the `create()` function as shown:
```js
function create() {
ball = game.add.sprite(50, 50, "ball");
}
```
This will add the ball to the game and render it on the screen. The first two parameters are the x and y coordinates of the canvas where you want it added, and the third one is the name of the asset we defined earlier. That's it — if you load your `index.html` file you will see the image already loaded and rendered on the canvas!
Compare your code
-----------------
You can check the finished code for this lesson for yourself in the live demo below, and play with it to better understand how it works:
Next steps
----------
Printing out the ball was easy; next, we'll try moving the ball on screen.
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Player paddle and controls - Game development | Player paddle and controls
==========================
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This is the **7th step** out of 16 of the Gamedev Phaser tutorial. You can find the source code as it should look after completing this lesson at Gamedev-Phaser-Content-Kit/demos/lesson07.html.
We have the ball moving and bouncing off the walls, but it quickly gets boring — there's no interactivity! We need a way to introduce gameplay, so in this article we'll create a paddle to move around and hit the ball with.
Rendering the paddle
--------------------
From the framework point of view the paddle is very similar to the ball — we need to add a variable to represent it, load the relevant image asset, and then do the magic.
### Loading the paddle
First, add the `paddle` variable we will be using in our game, right after the `ball` variable:
```js
let paddle;
```
Then, in the `preload` function, load the `paddle` image by adding the following new `load.image()` call:
```js
function preload() {
// …
game.load.image("ball", "img/ball.png");
game.load.image("paddle", "img/paddle.png");
}
```
### Adding the paddle graphic
Just so we don't forget, at this point you should grab the paddle graphic from GitHub, and save it in your `/img` folder.
### Rendering the paddle, with physics
Next up, we will initialize our paddle by adding the following `add.sprite()` call inside the `create()` function — add it right at the bottom:
```js
paddle = game.add.sprite(
game.world.width \* 0.5,
game.world.height - 5,
"paddle",
);
```
We can use the `world.width` and `world.height` values to position the paddle exactly where we want it: `game.world.width*0.5` will be right in the middle of the screen. In our case the world is the same as the Canvas, but for other types of games, like side-scrollers for example, the world will be bigger, and you can tinker with it to create interesting effects.
As you'll notice if you reload your `index.html` at this point, the paddle is currently not exactly in the middle. Why? Because the anchor from which the position is calculated always starts from the top left edge of the object. We can change that to have the anchor in the middle of the paddle's width and at the bottom of its height, so it's easier to position it against the bottom edge. Add the following line below the previous new one:
```js
paddle.anchor.set(0.5, 1);
```
The paddle is now positioned right where we want it to be. Now, to make it collide with the ball we have to enable physics for the paddle. Continue by adding the following new line, again at the bottom of the `create()` function:
```js
game.physics.enable(paddle, Phaser.Physics.ARCADE);
```
Now the magic can start to happen — the framework can take care of checking the collision detection on every frame. To enable collision detection between the paddle and ball, add the `collide()` method to the `update()` function as shown:
```js
function update() {
game.physics.arcade.collide(ball, paddle);
}
```
The first parameter is one of the objects we are interested in — the ball — and the second is the other one, the paddle. This works, but not quite as we expected it to — when the ball hits the paddle, the paddle falls off the screen! All we want is the ball bouncing off the paddle and the paddle staying in the same place. We can set the `body` of the paddle to be `immovable`, so it won't move when the ball hits it. To do this, add the below line at the bottom of the `create()` function:
```js
paddle.body.immovable = true;
```
Now it works as expected.
Controlling the paddle
----------------------
The next problem is that we can't move the paddle. To do that we can use the system's default input (mouse or touch, depending on platform) and set the paddle position to where the `input` position is. Add the following new line to the `update()` function, as shown:
```js
function update() {
game.physics.arcade.collide(ball, paddle);
paddle.x = game.input.x;
}
```
Now on every new frame the paddle's `x` position will adjust accordingly to the input's `x` position, however when we start the game, the position of the paddle is not in the middle. It's because the input position is not yet defined. To fix that we can set the default position (if an input position is not yet defined) to be the middle of the screen. Update the previous line as follows:
```js
paddle.x = game.input.x || game.world.width \* 0.5;
```
If you haven't already done so, reload your `index.html` and try it out!
Position the ball
-----------------
We have the paddle working as expected, so let's position the ball on it. It's very similar to positioning the paddle — we need to have it placed in the middle of the screen horizontally and at the bottom vertically with a little offset from the bottom. To place it exactly as we want it we will set the anchor to the exact middle of the ball. Find the existing `ball = game.add.sprite()` line, and replace it with the following two lines:
```js
ball = game.add.sprite(game.world.width \* 0.5, game.world.height - 25, "ball");
ball.anchor.set(0.5);
```
The velocity stays almost the same — we're just changing the second parameter's value from 150 to -150, so the ball will start the game by moving up instead of down. Find the existing `ball.body.velocity.set()` line and update it to the following:
```js
ball.body.velocity.set(150, -150);
```
Now the ball will start right from the middle of the paddle.
Compare your code
-----------------
You can check the finished code for this lesson in the live demo below, and play with it to understand better how it works:
Next steps
----------
We can move the paddle and bounce the ball off it, but what's the point if the ball is bouncing off the bottom edge of the screen anyway? Let's introduce the possibility of losing — also known as game over logic.
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Scaling - Game development | Scaling
=======
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This is the **2nd step** out of 16 of the Gamedev Phaser tutorial. You can find the source code as it should look after completing this lesson at Gamedev-Phaser-Content-Kit/demos/lesson02.html.
Scaling refers to how the game canvas will scale on different screen sizes. We can make the game scale to fit on any screen size automatically during the preload stage, so we don't have to worry about it later.
The Phaser scale object
-----------------------
There's a special `scale` object available in Phaser with a few handy methods and properties available. Update your existing `preload()` function as follows:
```js
function preload() {
game.scale.scaleMode = Phaser.ScaleManager.SHOW\_ALL;
game.scale.pageAlignHorizontally = true;
game.scale.pageAlignVertically = true;
}
```
`scaleMode` has a few different options available for how the Canvas can be scaled:
* `NO_SCALE` — nothing is scaled.
* `EXACT_FIT` — scale the canvas to fill all the available space both vertically and horizontally, without preserving the aspect ratio.
* `SHOW_ALL` — scales the canvas, but keeps the aspect ratio untouched, so images won't be skewed like in the previous mode. There might be black stripes visible on the edges of the screen, but we can live with that.
* `RESIZE` — creates the canvas with the same size as the available width and height, so you have to place the objects inside your game dynamically; this is more of an advanced mode.
* `USER_SCALE` — allows you to have custom dynamic scaling, calculating the size, scale and ratio on your own; again, this is more of an advanced mode
The other two lines of code in the `preload()` function are responsible for aligning the canvas element horizontally and vertically, so it is always centered on screen regardless of size.
Adding a custom canvas background color
---------------------------------------
We can also add a custom background color to our canvas, so it won't stay black. The `stage` object has a `backgroundColor` property for this purpose, which we can set using CSS color definition syntax. Add the following line below the other three you added earlier:
```js
game.stage.backgroundColor = "#eee";
```
Compare your code
-----------------
You can check the finished code for this lesson in the live demo below, and play with it to understand better how it works:
Next steps
----------
Now we've set up the scaling for our game, let's continue to the third lesson and work out how to load the assets and print them on screen.
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The score - Game development | The score
=========
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This is the **11th step** out of 16 of the Gamedev Phaser tutorial. You can find the source code as it should look after completing this lesson at Gamedev-Phaser-Content-Kit/demos/lesson11.html.
Having a score can also make the game more interesting — you can try to beat your own high score, or your friend's. In this article we'll add a scoring system to our game.
We will use a separate variable for storing the score and Phaser's `text()` method to print it out onto the screen.
New variables
-------------
Add two new variables right after the previously defined ones:
```js
// …
let scoreText;
let score = 0;
```
Adding score text to the game display
-------------------------------------
Now add this line at the end of the `create()` function:
```js
scoreText = game.add.text(5, 5, "Points: 0", {
font: "18px Arial",
fill: "#0095DD",
});
```
The `text()` method can take four parameters:
* The x and y coordinates to draw the text at.
* The actual text that will be rendered.
* The font style to render the text with.
The last parameter looks very similar to CSS styling. In our case the score text will be blue, sized at 18 pixels, and use the Arial font.
Updating the score when bricks are destroyed
--------------------------------------------
We will increase the number of points every time the ball hits a brick and update the `scoreText` to display the current score. This can be done using the `setText()` method — add the two new lines seen below to the `ballHitBrick()` function:
```js
function ballHitBrick(ball, brick) {
brick.kill();
score += 10;
scoreText.setText(`Points: ${score}`);
}
```
That's it for now — reload your `index.html` and check that the score updates on every brick hit.
Compare your code
-----------------
You can check the finished code for this lesson in the live demo below, and play with it to understand better how it works:
Next steps
----------
We now have a scoring system, but what's the point of playing and keeping score if you can't win? Let's see how we can add a victory state, allowing us to win the game.
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Win the game - Game development | Win the game
============
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This is the **12th step** out of 16 of the Gamedev Phaser tutorial. You can find the source code as it should look after completing this lesson at Gamedev-Phaser-Content-Kit/demos/lesson12.html.
Implementing winning in our game is quite easy: if you happen to destroy all the bricks, then you win.
How to win?
-----------
Add the following new code into your `ballHitBrick()` function:
```js
function ballHitBrick(ball, brick) {
brick.kill();
score += 10;
scoreText.setText(`Points: ${score}`);
let count_alive = 0;
for (let i = 0; i < bricks.children.length; i++) {
if (bricks.children[i].alive) {
count_alive++;
}
}
if (count_alive === 0) {
alert("You won the game, congratulations!");
location.reload();
}
}
```
We loop through the bricks in the group using `bricks.children`, checking for the aliveness of each with each brick's `.alive()` method. If there are no more bricks left alive, then we show a winning message, restarting the game once the alert is dismissed.
Compare your code
-----------------
You can check the finished code for this lesson in the live demo below, and play with it to understand better how it works:
Next steps
----------
Both losing and winning are implemented, so the core gameplay of our game is finished. Now let's add something extra — we'll give the player three lives instead of one.
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Animations and tweens - Game development | Animations and tweens
=====================
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This is the **14th step** out of 16 of the Gamedev Phaser tutorial. You can find the source code as it should look after completing this lesson at Gamedev-Phaser-Content-Kit/demos/lesson14.html.
To make the game look more juicy and alive we can use animations and tweens. This will result in a better, more entertaining experience. Let's explore how to implement Phaser animations and tweens in our game.
Animations
----------
In Phaser, animations, involve taking a spritesheet from an external source and displaying the sprites sequentially. As an example, we will make the ball wobble when it hits something.
First of all, grab the spritesheet from GitHub and save it in your `/img` directory.
Next, we will load the spritesheet — put the following line at the bottom of your `preload()` function:
```js
game.load.spritesheet("ball", "img/wobble.png", 20, 20);
```
Instead of loading a single image of the ball we can load the whole spritesheet — a collection of different images. We will show the sprites sequentially to create the illusion of animation. The `spritesheet()` method's two extra parameters determine the width and height of each single frame in the given spritesheet file, indicating to the program how to chop it up to get the individual frames.
Loading the animation
---------------------
Next up, go into your create() function, find the line that loads the ball sprite, and below it put the call to `animations.add()` seen below:
```js
ball = game.add.sprite(50, 250, "ball");
ball.animations.add("wobble", [0, 1, 0, 2, 0, 1, 0, 2, 0], 24);
```
To add an animation to the object we use the `animations.add()` method, which contains the following parameters
* The name we chose for the animation
* An array defining the order in which to display the frames during the animation. If you look again at the `wobble.png` image, you'll see there are three frames. Phaser extracts these and stores references to them in an array — positions 0, 1, and 2. The above array says that we are displaying frame 0, then 1, then 0, etc.
* The frame rate, in fps. Since we are running the animation at 24fps and there are 9 frames, the animation will display just under three times per second.
Applying the animation when the ball hits the paddle
----------------------------------------------------
In the `arcade.collide()` method call that handles the collision between the ball and the paddle (the first line inside `update()`, see below) we can add an extra parameter that specifies a function to be executed every time the collision happens, in the same fashion as the `ballHitBrick()` function. Update the first line inside `update()` as shown below:
```js
function update() {
game.physics.arcade.collide(ball, paddle, ballHitPaddle);
game.physics.arcade.collide(ball, bricks, ballHitBrick);
paddle.x = game.input.x || game.world.width \* 0.5;
}
```
Then we can create the `ballHitPaddle()` function (having `ball` and `paddle` as default parameters), playing the wobble animation when it is called. Add the following function just before your closing `</script>` tag:
```js
function ballHitPaddle(ball, paddle) {
ball.animations.play("wobble");
}
```
The animation is played every time the ball hits the paddle. You can add the `animations.play()` call inside the `ballHitBrick()` function too, if you feel it would make the game look better.
Tweens
------
Whereas animations play external sprites sequentially, tweens smoothly animate properties of an object in the gameworld, such as width or opacity.
Let's add a tween to our game to make the bricks smoothly disappear when they are hit by the ball. Go to your `ballHitBrick()` function, find your `brick.kill();` line, and replace it with the following:
```js
const killTween = game.add.tween(brick.scale);
killTween.to({ x: 0, y: 0 }, 200, Phaser.Easing.Linear.None);
killTween.onComplete.addOnce(() => {
brick.kill();
}, this);
killTween.start();
```
Let's walk through this so you can see what's happening here:
1. When defining a new tween you have to specify which property will be tweened — in our case, instead of hiding the bricks instantly when hit by the ball, we will make their width and height scale to zero, so they will nicely disappear. To the end, we use the `add.tween()` method, specifying `brick.scale` as the argument as this is what we want to tween.
2. The `to()` method defines the state of the object at the end of the tween. It takes an object containing the chosen parameter's desired ending values (scale takes a scale value, 1 being 100% of size, 0 being 0% of size, etc.), the time of the tween in milliseconds and the type of easing to use for the tween.
3. We will also add the optional `onComplete` event handler, which defines a function to be executed when the tween finishes.
4. The last thing do to is to start the tween right away using `start()`.
That's the expanded version of the tween definition, but we can also use the shorthand syntax:
```js
game.add
.tween(brick.scale)
.to({ x: 2, y: 2 }, 500, Phaser.Easing.Elastic.Out, true, 100);
```
This tween will double the brick's scale in half a second using Elastic easing, will start automatically, and have a delay of 100 milliseconds.
Compare your code
-----------------
You can check the finished code for this lesson in the live demo below, and play with it to understand better how it works:
Next steps
----------
Animations and tweens look very nice, but we can add even more to our game — in the next section we'll look at handling button inputs.
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Extra lives - Game development | Extra lives
===========
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This is the **13th step** out of 16 of the Gamedev Phaser tutorial. You can find the source code as it should look after completing this lesson at Gamedev-Phaser-Content-Kit/demos/lesson13.html.
We can make the game enjoyable for longer by adding lives. In this article we'll implement a lives system, so that the player can continue playing until they have lost three lives, not just one.
New variables
-------------
Add the following new variables below the existing ones in your code:
```js
let lives = 3;
let livesText;
let lifeLostText;
```
These respectively will store the number of lives, the text label that displays the number of lives that remain, and a text label that will be shown on screen when the player loses one of their lives.
Defining the new text labels
----------------------------
Defining the texts look like something we already did in the score lesson. Add the following lines below the existing `scoreText` definition inside your `create()` function:
```js
livesText = game.add.text(game.world.width - 5, 5, `Lives: ${lives}`, {
font: "18px Arial",
fill: "#0095DD",
});
livesText.anchor.set(1, 0);
lifeLostText = game.add.text(
game.world.width \* 0.5,
game.world.height \* 0.5,
"Life lost, click to continue",
{ font: "18px Arial", fill: "#0095DD" },
);
lifeLostText.anchor.set(0.5);
lifeLostText.visible = false;
```
The `livesText` and `lifeLostText` objects look very similar to the `scoreText` one — they define a position on the screen, the actual text to display, and the font styling. The former is anchored on its top right edge to align properly with the screen, and the latter is centered, both using `anchor.set()`.
The `lifeLostText` will be shown only when the life is lost, so its visibility is initially set to `false`.
### Making our text styling DRY
As you probably noticed we're using the same styling for all three texts: `scoreText`, `livesText` and `lifeLostText`. If we ever want to change the font size or color we will have to do it in multiple places. To make it easier for us to maintain in the future we can create a separate variable that will hold our styling, let's call it `textStyle` and place it before the text definitions:
```js
textStyle = { font: "18px Arial", fill: "#0095DD" };
```
We can now use this variable when styling our text labels — update your code so that the multiple instances of the text styling are replaced with the variable:
```js
scoreText = game.add.text(5, 5, "Points: 0", textStyle);
livesText = game.add.text(
game.world.width - 5,
5,
`Lives: ${lives}`,
textStyle,
);
livesText.anchor.set(1, 0);
lifeLostText = game.add.text(
game.world.width \* 0.5,
game.world.height \* 0.5,
"Life lost, click to continue",
textStyle,
);
lifeLostText.anchor.set(0.5);
lifeLostText.visible = false;
```
This way changing the font in one variable will apply the changes to every place it is used.
The lives handling code
-----------------------
To implement lives in our game, let's first change the ball's function bound to the `onOutOfBounds` event. Instead of executing an anonymous function and showing the alert right away:
```js
ball.events.onOutOfBounds.add(() => {
alert("Game over!");
location.reload();
}, this);
```
We will assign a new function called `ballLeaveScreen`; delete the previous event handler (shown above) and replace it with the following line:
```js
ball.events.onOutOfBounds.add(ballLeaveScreen, this);
```
We want to decrease the number of lives every time the ball leaves the canvas. Add the `ballLeaveScreen()` function definition at the end of our code:
```js
function ballLeaveScreen() {
lives--;
if (lives) {
livesText.setText(`Lives: ${lives}`);
lifeLostText.visible = true;
ball.reset(game.world.width \* 0.5, game.world.height - 25);
paddle.reset(game.world.width \* 0.5, game.world.height - 5);
game.input.onDown.addOnce(() => {
lifeLostText.visible = false;
ball.body.velocity.set(150, -150);
}, this);
} else {
alert("You lost, game over!");
location.reload();
}
}
```
Instead of instantly printing out the alert when you lose a life, we first subtract one life from the current number and check if it's a non-zero value. If yes, then the player still has some lives left and can continue to play — they will see the life lost message, the ball and paddle positions will be reset on screen and on the next input (click or touch) the message will be hidden and the ball will start to move again.
When the number of available lives reaches zero, the game is over and the game over alert message will be shown.
Events
------
You have probably noticed the `add()` and `addOnce()` method calls in the above two code blocks and wondered how they differ. The difference is that the `add()` method binds the given function and causes it to be executed every time the event occurs, while `addOnce()` is useful when you want to have the bound function executed only once and then unbound so it is not executed again. In our case, on every `outOfBounds` event the `ballLeaveScreen` will be executed, but when the ball leaves the screen we only want to remove the message from the screen once.
Compare your code
-----------------
You can check the finished code for this lesson in the live demo below, and play with it to understand better how it works:
Next steps
----------
Lives made the game more forgiving — if you lose one life, you still have two more left and can continue to play. Now let's expand the look and feel of the game by adding animations and tweens.
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Firefox - Mozilla | Firefox
=======
Firefox is Mozilla's popular Web browser, available for multiple platforms including Windows, macOS, and Linux on the desktop and all Android and iOS mobile devices. With broad compatibility, the latest in Web technologies, and powerful development tools, Firefox is a great choice for both Web developers and end users.
Firefox is an open source project; much of the code is contributed by our huge community of volunteers. Here you can learn about how to contribute to the Firefox project and you will also find links to information about the construction of Firefox add-ons, using the developer tools in Firefox, and other topics.
Learn how to create add-ons for Firefox, how to develop and build Firefox itself, and how the internals of Firefox and its subprojects work.
Key resources
-------------
Firefox developer guide
Our developer guide explains how to get Firefox source code, how to build it on Linux, macOS and Windows, how to find your way around, and how to contribute to the project.
Firefox add-on guide
The Add-on guide provides information about developing and deploying Firefox extensions.
Developer release notes
Developer-focused release notes; learn what new capabilities for both websites and add-ons arrive in each version of Firefox.
Firefox channels
----------------
Firefox is available in five **channels**.
### Firefox Nightly
Each night we build Firefox from the latest code in mozilla-central. These builds are for Firefox developers or those who want to try out the very latest cutting edge features while they're still under active development.
Download Firefox Nightly
### Firefox Developer Edition
This is a version of Firefox tailored for developers. Firefox Developer Edition has all the latest developer tools that have reached beta. We also add some extra features for developers that are only available in this channel. It uses its own path and profile, so that you can run it alongside Release or Beta Firefox.
Download Firefox Developer Edition
### Firefox Beta
Every four weeks, we take the features that are stable enough, and create a new version of Firefox Beta. Firefox Beta builds are for Firefox enthusiasts to test what's destined to become the next released Firefox version.
Download Firefox Beta
### Firefox
After stabilizing for another four weeks in Beta, we're ready to ship the new features to hundreds of millions of users in a new release version of Firefox.
Download Firefox
### Firefox Extended Support Release (ESR)
Firefox ESR is the long-term support edition of Firefox for desktop for use by organizations including schools, universities, businesses and others who need extended support for mass deployments.
Download Firefox ESR
Contents
--------
Experimental features in FirefoxThis page lists Firefox's experimental and partially implemented features, including those for proposed or cutting-edge web platform standards, along with information on the builds in which they are present, whether or not they are activated "by default", and which *preference* can be used to activate or deactivate them.
This allows you to test the features before they are released.
Firefox release notes for developersBelow you'll find links to the developer release notes for every Firefox release. These lovingly-crafted notes provide details on what features and APIs were added and improved and what bugs were eliminated in each version of Firefox. All written to give developers like you the information they need most. You're welcome.
See also
--------
* Mailing list
* Release schedule |
Add-ons - Mozilla | Add-ons
=======
Add-ons allow developers to extend and modify the functionality of Firefox. They are written using standard Web technologies - JavaScript, HTML, and CSS - plus some dedicated JavaScript APIs.
Among other things, an add-on could:
* Change the appearance or content of particular websites
* Modify the Firefox user interface
* Add new features to Firefox
There are several types of add-ons, but the most common type are extensions.
Developing extensions
---------------------
In the past, there were several toolsets for developing Firefox extensions, but as of November 2017, extensions must be built using WebExtensions APIs. Other toolsets, such as overlay add-ons, bootstrapped add-ons, and the Add-on SDK, are no longer supported.
Extensions written using WebExtensions APIs for Firefox are designed to be cross-browser compatible. In most cases, it will run in Chrome, Edge, and Opera with few if any changes. They are also fully compatible with multiprocess Firefox. You can see the APIs currently supported in Firefox and other browsers.
### Extension Workshop
The Firefox Extension Workshop can help you develop extensions for Firefox and give your users simple, yet powerful ways to customize their browsing experience. You'll find:
* Overview of the Firefox extension features
* Tools and processes for developing and testing
* How to publish your extension on addons.mozilla.org or distribute it yourself
* How to manage your published extension
* An enterprise guide for developing and using extensions
* How to develop themes for Firefox
* Firefox developer communities
### Extensions for Firefox for Android
In 2020, Mozilla will release a new Firefox for Android experience. This new, high-performance browser for Android has been rebuilt from the ground up using GeckoView, Mozilla's mobile browser engine. We are currently building support for the WebExtensions API on GeckoView.
### Migrate an existing extension
If you maintain a legacy extension, such as an XUL overlay, bootstrapped, or Add-on SDK-based extension, you can still port it to use WebExtension APIs. There are some porting resources on Firefox Extension Workshop, our site for Firefox-specific development resources.
For more information about transition support, please visit our wiki page.
Publishing add-ons
------------------
Addons.mozilla.org, commonly known as "AMO," is Mozilla's official site for developers to list add-ons, and for users to discover them. By uploading your add-on to AMO, you can participate in our community of users and creators and find an audience for your add-on.
You are not required to list your add-on on AMO, but your add-on must be signed by Mozilla else users will not be able to install it.
For an overview for the process of publishing your add-on see Signing and distributing your add-on.
Other types of add-ons
----------------------
In addition to extensions, there are a few other add-on types that allow users to customize Firefox. Those add-ons include:
* User dictionaries let you spell-check in different languages.
* Language packs let you have more languages available for the user interface of Firefox.
Contact us
----------
Check out the contact us page for details on how to get help, keep up to date with add-ons news, and give us feedback. |
Firefox release notes for developers - Mozilla | Firefox release notes for developers
====================================
Below you'll find links to the developer release notes for every Firefox release. These lovingly-crafted notes provide details on what features and APIs were added and improved and what bugs were eliminated in each version of Firefox. All written to give developers like you the information they need most. You're welcome.
1. Firefox 123 for developers
2. Firefox 122 for developers
3. Firefox 121 for developers
4. Firefox 120 for developers
5. Firefox 119 for developers
6. Firefox 118 for developers
7. Firefox 117 for developers
8. Firefox 116 for developers
9. Firefox 115 for developers
10. Firefox 114 for developers
11. Firefox 113 for developers
12. Firefox 112 for developers
13. Firefox 111 for developers
14. Firefox 110 for developers
15. Firefox 109 for developers
16. Firefox 108 for developers
17. Firefox 107 for developers
18. Firefox 106 for developers
19. Firefox 105 for developers
20. Firefox 104 for developers
21. Firefox 103 for developers
22. Firefox 102 for developers
23. Firefox 101 for developers
24. Firefox 100 for developers
25. Firefox 99 for developers
26. Firefox 98 for developers
27. Firefox 97 for developers
28. Firefox 96 for developers
29. Firefox 95 for developers
30. Firefox 94 for developers
31. Firefox 93 for developers
32. Firefox 92 for developers
33. Firefox 91 for developers
34. Firefox 90 for developers
35. Firefox 89 for developers
36. Firefox 88 for developers
37. Firefox 87 for developers
38. Firefox 86 for developers
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Whew! That's a lot of Firefoxen! |
Experimental features in Firefox - Mozilla | Experimental features in Firefox
================================
This page lists Firefox's experimental and partially implemented features, including those for proposed or cutting-edge web platform standards, along with information on the builds in which they are present, whether or not they are activated "by default", and which *preference* can be used to activate or deactivate them.
This allows you to test the features before they are released.
New features appear first in the Firefox Nightly build, where they are often enabled by default.
They later propagate though to Firefox Developer Edition and eventually to the release build.
After a feature is enabled by default in a release build, it is no longer considered experimental and should be removed from the topic.
Experimental features can be enabled or disabled using the Firefox Configuration Editor (enter `about:config` in the Firefox address bar) by modifying the associated *preference* listed below.
**Note:** For editors - when adding features to these tables, please try to include a link to the relevant bug or bugs using `[Firefox bug <number>](https://bugzil.la/<number>)`.
HTML
----
### Layout for input type="search"
Layout for `input type="search"` has been updated. This causes a search field to have a clear icon once someone starts typing in it, to match other browser implementations. (See Firefox bug 558594 for more details.)
| Release channel | Version added | Enabled by default? |
| --- | --- | --- |
| Nightly | 81 | No |
| Developer Edition | 81 | No |
| Beta | 81 | No |
| Release | 81 | No |
| Preference name | `layout.forms.input-type-search.enabled` |
### Toggle password display
HTML password input elements (`<input type="password">`) include an "eye" icon that can be toggled to display or obscure the password text (Firefox bug 502258).
| Release channel | Version added | Enabled by default? |
| --- | --- | --- |
| Nightly | 96 | No |
| Developer Edition | 96 | No |
| Beta | 96 | No |
| Release | 96 | No |
| Preference name | `layout.forms.input-type-show-password-button.enabled` |
### Declarative shadow DOM
The `<template>` element now supports a `shadowrootmode` attribute which can be set to either `open` or `closed`, the same values as the `mode` option of the `attachShadow()` method. It allows the creation of a shadow DOM subtree declaratively. (See Firefox bug 1712140 for more details.)
| Release channel | Version added | Enabled by default? |
| --- | --- | --- |
| Nightly | 122 | Yes |
| Developer Edition | 122 | No |
| Beta | 122 | No |
| Release | 122 | No |
| Preference name | `dom.webcomponents.shadowdom.declarative.enabled` |
CSS
---
### Hex boxes to display stray control characters
This feature renders control characters (Unicode category Cc) other than *tab* (`U+0009`), *line feed* (`U+000A`), *form feed* (`U+000C`), and *carriage return* (`U+000D`) as a hexbox when they are not expected. (See Firefox bug 1099557 for more details.)
| Release channel | Version added | Enabled by default? |
| --- | --- | --- |
| Nightly | 43 | Yes |
| Developer Edition | 43 | No |
| Beta | 43 | No |
| Release | 43 | No |
| Preference name | `layout.css.control-characters.enabled` or
`layout.css.control-characters.visible` |
### initial-letter property
The `initial-letter` CSS property is part of the CSS Inline Layout specification and allows you to specify how dropped, raised, and sunken initial letters are displayed. (See Firefox bug 1223880 for more details.)
| Release channel | Version added | Enabled by default? |
| --- | --- | --- |
| Nightly | 50 | No |
| Developer Edition | 50 | No |
| Beta | 50 | No |
| Release | 50 | No |
| Preference name | `layout.css.initial-letter.enabled` |
### content-visibility: auto value
The `content-visibility` CSS property value `auto` allows content to skip rendering if it is not relevant to the user.
(See Firefox bug 1798485 for more details.)
| Release channel | Version added | Enabled by default? |
| --- | --- | --- |
| Nightly | 113 | Yes |
| Developer Edition | 109 | No |
| Beta | 109 | No |
| Release | 109 | No |
| Preference name | `layout.css.content-visibility.enabled` |
Note:
* The related `contentvisibilityautostatechange` event and associated `ContentVisibilityAutoStateChangeEvent` interface were added in version 110, and are gated by the same preference.
These can be used by application code to monitor visibility changes and stop processes related to rendering the element when the user agent is skipping its contents.
(See Firefox bug 1791759 for more details.)
* The `Element.checkVisibility()` `options` object parameter now takes the property `contentVisibilityAuto`, which can be set `true` to test if the element has `content-visibility: auto` set and is currently skipping rendering its content (the `options` object also takes new values `opacityProperty` and `visibilityProperty` but these are not related to `content-visibility`).
(See Firefox bug 1859852 for more details).
### Single numbers as aspect ratio in media queries
Support for using a single `<number>` as a `<ratio>` when specifying the aspect ratio for a media query. (See Firefox bug 1565562 for more details.)
| Release channel | Version added | Enabled by default? |
| --- | --- | --- |
| Nightly | 70 | No |
| Developer Edition | 70 | No |
| Beta | 70 | No |
| Release | 70 | No |
| Preference name | `layout.css.aspect-ratio-number.enabled` |
### backdrop-filter property
The `backdrop-filter` property applies filter effects to the area behind an element. (See Firefox bug 1178765 for more details.)
| Release channel | Version added | Enabled by default? |
| --- | --- | --- |
| Nightly | 70 | No |
| Developer Edition | 70 | No |
| Beta | 70 | No |
| Release | 70 | No |
| Preference name | `layout.css.backdrop-filter.enabled` |
### Masonry grid layout
Adds support for a masonry-style layout based on grid layout where one axis has a masonry layout and the other has a normal grid layout. This allows developers to easily create gallery style layouts like on Pinterest. See Firefox bug 1607954 for more details.
| Release channel | Version added | Enabled by default? |
| --- | --- | --- |
| Nightly | 77 | Yes |
| Developer Edition | 77 | No |
| Beta | 77 | No |
| Release | 77 | No |
| Preference name | `layout.css.grid-template-masonry-value.enabled` |
### fit-content() function
The `fit-content()` function as it applies to `width` and other sizing properties. This function is already well-supported for CSS Grid Layout track sizing. (See Firefox bug 1312588 for more details.)
| Release channel | Version added | Enabled by default? |
| --- | --- | --- |
| Nightly | 91 | No |
| Developer Edition | 91 | No |
| Beta | 91 | No |
| Release | 91 | No |
| Preference name | `layout.css.fit-content-function.enabled` |
### Scroll-driven animations
Earlier called "scroll-linked animations", a scroll-driven animation depends on the scroll position of a scrollbar instead of time or some other dimension.
The `scroll-timeline-name` and `scroll-timeline-axis` properties (and the `scroll-timeline` shorthand property) allow you to specify that a particular scrollbar in a particular named container can be used as the source for a scroll-driven animation.
The scroll timeline can then be associated with an animation by setting the `animation-timeline` property to the name value defined using `scroll-timeline-name`.
When using the `scroll-timeline` shorthand property, the order of the property values must be `scroll-timeline-name` followed by `scroll-timeline-axis`. The longhand and shorthand properties are both available behind the preference.
You can alternatively use the `scroll()` functional notation with `animation-timeline` to indicate that a scrollbar axis in an ancestor element will be used for the timeline.
For more information, see Firefox bug 1807685, Firefox bug 1804573, Firefox bug 1809005, Firefox bug 1676791, Firefox bug 1754897, and Firefox bug 1737918.
| Release channel | Version added | Enabled by default? |
| --- | --- | --- |
| Nightly | 110 | No |
| Developer Edition | 110 | No |
| Beta | 110 | No |
| Release | 110 | No |
| Preference name | `layout.css.scroll-driven-animations.enabled` |
### @font-face src feature checking
The `@font-face` `src` descriptor now supports the `tech()` function, allowing fallback of whether a font resource is downloaded based on whether the user-agent supports a particular font feature or technology.
See Firefox bug 1715546 for more details.
| Release channel | Version added | Enabled by default? |
| --- | --- | --- |
| Nightly | 105 | Yes |
| Developer Edition | 105 | No |
| Beta | 105 | No |
| Release | 105 | No |
| Preference name | `layout.css.font-tech.enabled` |
### font-variant-emoji
The CSS `font-variant-emoji` property allows you to set a default presentation style for displaying emojis.
See (Firefox bug 1461589) for more details.
| Release channel | Version added | Enabled by default? |
| --- | --- | --- |
| Nightly | 108 | Yes |
| Developer Edition | 108 | No |
| Beta | 108 | No |
| Release | 108 | No |
| Preference name | `layout.css.font-variant-emoji.enabled` |
### page-orientation
The **`page-orientation`** CSS descriptor for the `@page` at-rule controls the rotation of a printed page. It handles the flow of content across pages when the orientation of a page is changed. This behavior differs from the `size` descriptor in that a user can define the direction in which to rotate the page.
See (Firefox bug 1673987) for more details.
| Release channel | Version added | Enabled by default? |
| --- | --- | --- |
| Nightly | 111 | Yes |
| Developer Edition | 111 | No |
| Beta | 111 | No |
| Release | 111 | No |
| Preference name | `layout.css.page-orientation.enabled` |
### prefers-reduced-transparency media feature
The CSS `prefers-reduced-transparency` media feature lets you detect if a user has enabled the setting to minimize the amount of transparent or translucent layer effects on their device.
See (Firefox bug 1736914) for more details.
| Release channel | Version added | Enabled by default? |
| --- | --- | --- |
| Nightly | 113 | No |
| Developer Edition | 113 | No |
| Beta | 113 | No |
| Release | 113 | No |
| Preference name | `layout.css.prefers-reduced-transparency.enabled` |
### inverted-colors media feature
The CSS `inverted-colors` media feature lets you detect if a user agent or the underlying operating system is inverting colors.
See (Firefox bug 1794628) for more details.
| Release channel | Version added | Enabled by default? |
| --- | --- | --- |
| Nightly | 114 | No |
| Developer Edition | 114 | No |
| Beta | 114 | No |
| Release | 114 | No |
| Preference name | `layout.css.inverted-colors.enabled` |
### Named view progress timelines property
The CSS `view-timeline-name` property lets you give a name to particular element, identifying that its ancestor scroller element is the source of a view progress timeline.
The name can then be assigned to the `animation-timeline`, which then animates the associated element as it moves through the visible area of its ancestor scroller.
See (Firefox bug 1737920) for more details.
| Release channel | Version added | Enabled by default? |
| --- | --- | --- |
| Nightly | 114 | No |
| Developer Edition | 114 | No |
| Beta | 114 | No |
| Release | 114 | No |
| Preference name | `layout.css.scroll-driven-animations.enabled` |
### Anonymous view progress timelines function
The CSS `view()` function lets you specify that the `animation-timeline` for an element is a view progress timeline, which will animate the element as it moves through the visible area of its ancestor scroller.
The function defines the axis of the parent element that supplies the timeline, along with the inset within the visible area at which the animation starts and begins.
See (Firefox bug 1808410) for more details.
| Release channel | Version added | Enabled by default? |
| --- | --- | --- |
| Nightly | 114 | No |
| Developer Edition | 114 | No |
| Beta | 114 | No |
| Release | 114 | No |
| Preference name | `layout.css.scroll-driven-animations.enabled` |
### zoom property
The non-standard CSS `zoom` property is enabled in the Nightly release and lets you magnify an element similar to the `transform` property, but it affects the layout size of the element.
See (Firefox bug 1855763 and Firefox bug 390936) for more details.
| Release channel | Version added | Enabled by default? |
| --- | --- | --- |
| Nightly | 120 | Yes |
| Developer Edition | 120 | No |
| Beta | 120 | No |
| Release | 120 | No |
| Preference name | `layout.css.zoom.enabled` |
To ensure compatibility with these changes, the Vendor-prefixed transform properties and the Vendor-prefixed transition properties are disabled in the Nightly release.
These changes are described in the following sections.
### text-wrap: balance & stable values
The `text-wrap` CSS property values `balance` and `stable` allow the layout of short content to be wrapped in a balanced manner and for editable content to not reflow while the user is editing it, respectively.
(See Firefox bug 1731541 for more details.)
| Release channel | Version added | Enabled by default? |
| --- | --- | --- |
| Nightly | 120 | Yes |
| Developer Edition | 120 | No |
| Beta | 120 | No |
| Release | 120 | No |
| Preference name | `layout.css.text-wrap-balance.enabled, layout.css.text-wrap-balance.limit, layout.css.text-wrap-balance-after-clamp.enabled` |
#### Vendor-prefixed transform properties
The `-moz-` prefixed CSS transform properties have been disabled in the Nightly release via the `layout.css.prefixes.transforms` preference being set to `false` (Firefox bug 1855763).
Specifically, the disabled properties are:
* `-moz-backface-visibility`
* `-moz-perspective`
* `-moz-perspective-origin`
* `-moz-transform`
* `-moz-transform-origin`
* `-moz-transform-style`
| Release channel | Version added | Enabled by default? |
| --- | --- | --- |
| Nightly | 120 | No |
| Developer Edition | 120 | Yes |
| Beta | 120 | Yes |
| Release | 120 | Yes |
| Preference name | `layout.css.prefixes.transforms` |
#### Vendor-prefixed transition properties
The `-moz-` prefixed CSS transitions properties have been disabled in the Nightly release via the `layout.css.prefixes.transitions` preference being set to `false` (Firefox bug 1855763).
Specifically, the disabled properties are:
* `-moz-transition`
* `-moz-transition-delay`
* `-moz-transition-duration`
* `-moz-transition-property`
* `-moz-transition-timing-function`
| Release channel | Version added | Enabled by default? |
| --- | --- | --- |
| Nightly | 120 | No |
| Developer Edition | 120 | Yes |
| Beta | 120 | Yes |
| Release | 120 | Yes |
| Preference name | `layout.css.prefixes.transitions` |
SVG
---
### SVGPathSeg APIs
The SVGPathSeg APIs are being unshipped, and have been placed behind a preference.
This includes: `SVGPathSegList`, SVGPathElement.getPathSegAtLength(), `SVGAnimatedPathData`.
(See Firefox bug 1388931 for more details.)
| Release channel | Version removed | Enabled by default? |
| --- | --- | --- |
| Nightly | 97 | No |
| Developer Edition | 97 | No |
| Beta | 97 | No |
| Release | 97 | No |
| Preference name | `dom.svg.pathSeg.enabled` |
JavaScript
----------
### Intl.Segmenter
The `Intl.Segmenter` is supported in nightly builds, allowing developers to perform locale-sensitive text segmentation.
This enables splitting a string into meaningful items (graphemes, words or sentences) in different locales.
(See Firefox bug 1423593 for more details.)
| Release channel | Version added | Enabled by default? |
| --- | --- | --- |
| Nightly | 122 | Yes |
| Developer Edition | NA | No |
| Beta | NA | No |
| Release | NA | No |
| Preference name | None |
APIs
----
### Graphics: Canvas, WebGL, and WebGPU
#### Hit regions
Whether the mouse coordinates are within a particular area on the canvas is a common problem to solve. The hit region API allows you to define an area of your canvas and provides another possibility to expose interactive content on a canvas to accessibility tools.
| Release channel | Version added | Enabled by default? |
| --- | --- | --- |
| Nightly | 30 | No |
| Developer Edition | 30 | No |
| Beta | 30 | No |
| Release | 30 | No |
| Preference name | `canvas.hitregions.enabled` |
#### WebGL: Draft extensions
When this preference is enabled, any WebGL extensions currently in "draft" status which are being tested are enabled for use. Currently, there are no WebGL extensions being tested by Firefox.
#### WebGPU API
The WebGPU API provides low-level support for performing computation and graphics rendering using the Graphics Processing Unit (GPU) of the user's device or computer. See Firefox bug 1602129 for our progress on this API.
| Release channel | Version added | Enabled by default? |
| --- | --- | --- |
| Nightly | 113 | Yes |
| Developer Edition | 73 | No |
| Beta | 73 | No |
| Release | 73 | No |
| Preference name | `dom.webgpu.enabled` |
### WebRTC and media
The following experimental features include those found in the WebRTC API, the Web Audio API, the Media Source Extensions API, the Encrypted Media Extensions API, and the Media Capture and Streams API.
#### Asynchronous SourceBuffer add and remove
This adds the promise-based methods `appendBufferAsync()` and `removeAsync()` for adding and removing media source buffers to the `SourceBuffer` interface. See Firefox bug 1280613 and Firefox bug 778617 for more information.
| Release channel | Version added | Enabled by default? |
| --- | --- | --- |
| Nightly | 62 | No |
| Developer Edition | 62 | No |
| Beta | 62 | No |
| Release | 62 | No |
| Preference name | `media.mediasource.experimental.enabled` |
#### AVIF compliance strictness
The `image.avif.compliance_strictness` preference can be used to control the *strictness* applied when processing AVIF images.
This allows Firefox users to display images that render on some other browsers, even if they are not strictly compliant.
Permitted values are:
* `0`: Accept images with specification violations in both recommendations ("should" language) and requirements ("shall" language), provided they can be safely or unambiguously interpreted.
* `1` (default): Reject violations of requirements, but allow violations of recommendations.
* `2`: Strict. Reject any violations in requirements or recommendations.
| Release channel | Version added | Default value |
| --- | --- | --- |
| Nightly | 92 | 1 |
| Developer Edition | 92 | 1 |
| Beta | 92 | 1 |
| Release | 92 | 1 |
| Preference name | `image.avif.compliance_strictness` |
#### JPEG XL support
Firefox supports JPEG XL images if this feature is enabled.
See Firefox bug 1539075 for more details.
Note that, as shown below, the feature is only available on Nightly builds (irrespective of whether the preference is set).
| Release channel | Version added | Enabled by default? |
| --- | --- | --- |
| Nightly | 90 | No |
| Developer Edition | — | — |
| Beta | — | — |
| Release | — | — |
| Preference name | `image.jxl.enabled` |
#### OpenFont COLRv1 fonts
This feature provides support for the OpenFont COLRv1 font specification.
This enables compression-friendly color vector fonts with gradients, compositing and blending to be loaded using the CSS `@font-face` rule, or the CSS Font Loading API.
See Firefox bug 1740530 for more details.
| Release channel | Version added | Enabled by default? |
| --- | --- | --- |
| Nightly | 105 | No |
| Developer Edition | 105 | No |
| Beta | 105 | No |
| Release | 105 | No |
| Preference name | `gfx.font_rendering.colr_v1.enabled` |
#### CSS Properties and Values API
The CSS Properties and Values API allows developers to register custom CSS properties through JavaScript via `registerProperty()` or in CSS using the `@property` at-rule.
Registering properties using these two methods allows for type checking, default values, and properties that do or do not inherit values from their parent elements.
See Firefox bug 1840480 for more details.
| Release channel | Version added | Enabled by default? |
| --- | --- | --- |
| Nightly | 116 | Yes |
| Developer Edition | 116 | No |
| Beta | 116 | No |
| Release | 116 | No |
| Preference name | `layout.css.property-and-value-api.enabled` |
#### CSS Custom Highlight API
The CSS Custom Highlight API provides a mechanism for styling arbitrary text ranges in a document (generalizing the behavior of other highlight pseudo-elements such as `::selection`, `::spelling-error`, `::grammar-error`, and `::target-text`).
The ranges are defined in JavaScript using `Range` instances grouped in a `Highlight`, and then registered with a name using `HighlightRegistry`.
The CSS `::highlight` pseudo-element is used to apply styles to a registered highlight.
See Firefox bug 1703961 for more details.
| Release channel | Version added | Enabled by default? |
| --- | --- | --- |
| Nightly | 117 | Yes |
| Developer Edition | 117 | No |
| Beta | 117 | No |
| Release | 117 | No |
| Preference name | `dom.customHighlightAPI.enabled` |
### Service Workers
#### Preloading of service worker resources on navigation
The `NavigationPreloadManager` interface can be used to enable preloading of resources when navigating to a page.
Preloading occurs in parallel with worker bootup, reducing the total time from start of navigation until resources are fetched.
| Release channel | Version added | Enabled by default? |
| --- | --- | --- |
| Nightly | 99 | yes |
| Developer Edition | 97 | No |
| Beta | 97 | No |
| Release | 97 | No |
| Preference name | `dom.serviceWorkers.navigationPreload.enabled` |
### WebVR API
#### WebVR API (Disabled)
The deprecated WebVR API is on the path for removal.
It is disabled by default on all builds Firefox bug 1750902.
| Release channel | Version removed | Enabled by default? |
| --- | --- | --- |
| Nightly | 98 | No |
| Developer Edition | 98 | No |
| Beta | 98 | No |
| Release | 98 | No |
| Preference name | `dom.vr.enabled` |
### HTML DOM API
#### Popover API
Firefox now supports the Popover API.
The following Web APIs are now implemented:
* `HTMLButtonElement.popoverTargetElement` and `HTMLButtonElement.popoverTargetAction`.
* `HTMLInputElement.popoverTargetElement` and `HTMLInputElement.popoverTargetAction`.
* `HTMLElement.popover`, `HTMLElement.hidePopover()`, `HTMLElement.showPopover()`, and `HTMLElement.togglePopover()`.
* `HTMLElement` `beforetoggle` event, `HTMLElement` `toggle_event` event, and `ToggleEvent`.
CSS updates include:
* `:popover-open`
* `::backdrop` has been extended to support popovers
The following HTML global attributes are supported:
* `popovertarget`
* `popovertargetaction`
See Firefox bug 1823757 for more details.
| Release channel | Version added | Enabled by default? |
| --- | --- | --- |
| Nightly | 122 | Yes |
| Developer Edition | 114 | No |
| Beta | 114 | No |
| Release | 114 | No |
| Preference name | `dom.element.popover.enabled` |
#### HTMLMediaElement method: setSinkId()
`HTMLMediaElement.setSinkId()` allows you to set the sink ID of an audio output device on an `HTMLMediaElement`, thereby changing where the audio is being output. See Firefox bug 934425 for more details.
| Release channel | Version added | Enabled by default? |
| --- | --- | --- |
| Nightly | 64 | No |
| Developer Edition | 64 | No |
| Beta | 64 | No |
| Release | 64 | No |
| Preference name | `media.setsinkid.enabled` |
#### HTMLMediaElement properties: audioTracks and videoTracks
Enabling this feature adds the `HTMLMediaElement.audioTracks` and `HTMLMediaElement.videoTracks` properties to all HTML media elements. However, because Firefox doesn't currently support multiple audio and video tracks, the most common use cases for these properties don't work, so they're both disabled by default. See Firefox bug 1057233 for more details.
| Release channel | Version added | Enabled by default? |
| --- | --- | --- |
| Nightly | 33 | No |
| Developer Edition | 33 | No |
| Beta | 33 | No |
| Release | 33 | No |
| Preference name | `media.track.enabled` |
#### ClipboardItem
The `ClipboardItem` interface of the `Clipboard API` is now supported. It is available in nightly or early beta builds.
(See Firefox bug 1809106 for more details.)
| Release channel | Version added | Enabled by default? |
| --- | --- | --- |
| Nightly | 122 | Yes |
| Developer Edition | 87 | No |
| Beta | 122 | Yes |
| Release | 87 | No |
| Preference name | `dom.events.asyncClipboard.clipboardItem` |
#### Clipboard read and write
The Clipboard.read(), Clipboard.readText(), and Clipboard.write() methods of the `Clipboard` interface are now available in nightly and early beta builds
(See Firefox bug 1809106 for more details.)
| Release channel | Version added | Enabled by default? |
| --- | --- | --- |
| Nightly | 122 | Yes |
| Developer Edition | 90 | No |
| Beta | Yes | No |
| Release | 90 | No |
| Preference name | `dom.events.asyncClipboard.readText` and `dom.events.asyncClipboard.clipboardItem` |
#### HTML Sanitizer API
The `HTML Sanitizer API` allow developers to take untrusted strings of HTML and sanitize them for safe insertion into a document's DOM. Default elements within each configuration property (those to be sanitized) are still under consideration. Due to this the config parameter has not been implemented (see `the constructor` for more information). See Firefox bug 1673309 for more details.
| Release channel | Version added | Enabled by default? |
| --- | --- | --- |
| Nightly | 84 | No |
| Developer Edition | 84 | No |
| Beta | 84 | No |
| Release | 84 | No |
| Preference name | `dom.security.sanitizer.enabled` |
#### GeometryUtils methods: convertPointFromNode(), convertRectFromNode(), and convertQuadFromNode()
The `GeometryUtils` methods `convertPointFromNode()`, `convertRectFromNode()`, and `convertQuadFromNode()` map the given point, rectangle, or quadruple from the `Node` on which they're called to another node. (See Firefox bug 918189 for more details.)
| Release channel | Version added | Enabled by default? |
| --- | --- | --- |
| Nightly | 31 | Yes |
| Developer Edition | 31 | No |
| Beta | 31 | No |
| Release | 31 | No |
| Preference name | `layout.css.convertFromNode.enable` |
#### GeometryUtils method: getBoxQuads()
The `GeometryUtils` method `getBoxQuads()` returns the CSS boxes for a `Node` relative to any other node or viewport. (See Firefox bug 917755 for more details.)
| Release channel | Version added | Enabled by default? |
| --- | --- | --- |
| Nightly | 31 | Yes |
| Developer Edition | 31 | No |
| Beta | 31 | No |
| Release | 31 | No |
| Preference name | `layout.css.getBoxQuads.enabled` |
#### Custom element state pseudo-class
Custom elements can expose their internal state via the `states` property as a `CustomStateSet`. A CSS custom state pseudo-class such as `:--somestate` can match that element's state.
(See Firefox bug 1861466 for more details.)
| Release channel | Version added | Enabled by default? |
| --- | --- | --- |
| Nightly | 121 | No |
| Developer Edition | 121 | No |
| Beta | 121 | No |
| Release | 121 | No |
| Preference name | `dom.element.customstateset.enabled` |
### Payment Request API
#### Primary payment handling
The Payment Request API provides support for handling web-based payments within web content or apps. Due to a bug that came up during testing of the user interface, we have decided to postpone shipping this API while discussions over potential changes to the API are held. Work is ongoing. (See Firefox bug 1318984 for more details.)
| Release channel | Version added | Enabled by default? |
| --- | --- | --- |
| Nightly | 55 | No |
| Developer Edition | 55 | No |
| Beta | 55 | No |
| Release | 55 | No |
| Preference name | `dom.payments.request.enabled` and`dom.payments.request.supportedRegions` |
### WebShare API
The Web Share API allows sharing of files, URLs and other data from a site.
This feature is enabled on Android in all builds, but behind a preference on Desktop (unless specified below).
| Release channel | Version changed | Enabled by default? |
| --- | --- | --- |
| Nightly | 71 | No (default). Yes (Windows from version 92) |
| Developer Edition | 71 | No |
| Beta | 71 | No |
| Release | 71 | No (Desktop). Yes (Android). |
| Preference name | `dom.webshare.enabled` |
### Screen Orientation API
#### ScreenOrientation.lock()
The `ScreenOrientation.lock()` method allows a device to be locked to a particular orientation, if supported by the device and allowed by browser pre-lock requirements.
Typically locking the orientation is only allowed on mobile devices when the document is being displayed full screen.
See Firefox bug 1697647 for more details.
| Release channel | Version changed | Enabled by default? |
| --- | --- | --- |
| Nightly | 111 | Yes |
| Developer Edition | 97 | No |
| Beta | 97 | No |
| Release | 97 | No |
| Preference name | `dom.screenorientation.allow-lock` |
### Screen Wake Lock API
The Screen Wake Lock API allows a web application to request that the screen not be dimmed or locked while it is active.
This is useful for navigation and reading applications, and any application where the screen doesn't get regular tactile input while the application is in use (the default way to keep a screen awake).
The API is accessed through `Navigator.wakeLock` in secure contexts, which returns a `WakeLock`.
This can be used to request a `WakeLockSentinel` that can be used to monitor the status of the wake lock, and release it manually.
See Firefox bug 1589554 for more details.
| Release channel | Version changed | Enabled by default? |
| --- | --- | --- |
| Nightly | 122 | Yes |
| Developer Edition | 122 | No |
| Beta | 122 | No |
| Release | 122 | No |
| Preference name | `dom.screenwakelock.enabled` |
### Prioritized Task Scheduling API
The Prioritized Task Scheduling API provides a standardized way to prioritize all tasks belonging to an application, whether they defined in a website developer's code, or in third party libraries and frameworks.
This is enabled on Firefox Nightly (only) from Firefox 101.
No preference is provided to allow it to be enabled in other releases.
### Notifications API
Notifications have the `requireInteraction` property set to true by default on Windows systems and in the Nightly release (Firefox bug 1794475).
| Release channel | Version changed | Enabled by default? |
| --- | --- | --- |
| Nightly | 117 | Yes |
| Developer Edition | 117 | No |
| Beta | 117 | No |
| Release | 117 | Windows only |
| Preference name | `dom.webnotifications.requireinteraction.enabled` |
Security and privacy
--------------------
### Block plain text requests from Flash on encrypted pages
In order to help mitigate man-in-the-middle (MitM) attacks caused by Flash content on encrypted pages, a preference has been added to treat `OBJECT_SUBREQUEST`s as active content. See Firefox bug 1190623 for more details.
| Release channel | Version added | Enabled by default? |
| --- | --- | --- |
| Nightly | 59 | No |
| Developer Edition | 59 | No |
| Beta | 59 | No |
| Release | 59 | No |
| Preference name | `security.mixed_content.block_object_subrequest` |
### Insecure page labeling
These two preferences add a "Not secure" text label in the address bar next to the traditional lock icon when a page is loaded insecurely (that is, using HTTP rather than HTTPS). See Firefox bug 1335970 for more details.
| Release channel | Version added | Enabled by default? |
| --- | --- | --- |
| Nightly | 60 | No |
| Developer Edition | 60 | No |
| Beta | 60 | No |
| Release | 60 | No |
| Preference name | `security.insecure_connection_text.enabled` for normal
browsing mode;
`security.insecure_connection_text.pbmode.enabled` for
private browsing mode
|
### Upgrading mixed display content
When enabled, this preference causes Firefox to automatically upgrade requests for media content from HTTP to HTTPS on secure pages. The intent is to prevent mixed-content conditions in which some content is loaded securely while other content is insecure. If the upgrade fails (because the media's host doesn't support HTTPS), the media is not loaded. (See Firefox bug 1435733 for more details.)
This also changes the console warning; if the upgrade succeeds, the message indicates that the request was upgraded, instead of showing a warning.
| Release channel | Version added | Enabled by default? |
| --- | --- | --- |
| Nightly | 84 | Yes |
| Developer Edition | 60 | No |
| Beta | 60 | No |
| Release | 60 | No |
| Preference name | `security.mixed_content.upgrade_display_content` |
### Permissions Policy / Feature policy
Permissions Policy allows web developers to selectively enable, disable, and modify the behavior of certain features and APIs in the browser. It is similar to CSP but controls features instead of security behavior.
This is implemented in Firefox as **Feature Policy**, the name used in an earlier version of the specification.
Note that supported policies can be set through the `allow` attribute on `<iframe>` elements even if the user preference is not set.
| Release channel | Version added | Enabled by default? |
| --- | --- | --- |
| Nightly | 65 | No |
| Developer Edition | 65 | No |
| Beta | 65 | No |
| Release | 65 | No |
| Preference name | `dom.security.featurePolicy.header.enabled` |
### Clear-Site-Data "cache" directive
The `Clear-Site-Data` HTTP response header `cache` directive clears the browser cache for the requesting website.
**Note:** This was originally enabled by default, but put behind a preference in version 94 (Firefox bug 1729291).
| Release channel | Version added | Enabled by default? |
| --- | --- | --- |
| Nightly | 63 | No |
| Developer Edition | 63 | No |
| Beta | 63 | No |
| Release | 63 | No |
| Preference name | `privacy.clearsitedata.cache.enabled` |
HTTP
----
### SameSite=Lax by default
`SameSite` cookies have a default value of `Lax`.
With this setting, cookies are only sent when a user is navigating to the origin site, not for cross-site subrequests to load images or frames into a third party site and so on.
For more details see Firefox bug 1617609.
| Release channel | Version added | Enabled by default? |
| --- | --- | --- |
| Nightly | 69 | No |
| Developer Edition | 69 | No |
| Beta | 69 | No |
| Release | 69 | No |
| Preference name | `network.cookie.sameSite.laxByDefault` |
### HTTP Status 103
The `103 Early Hints` HTTP information response status code may be sent by a server to allow a user agent to start preloading resources while the server is still preparing the full response.
Note that using the header to preconnect to sites is already supported.
For more details see Firefox bug 1813035.
| Release channel | Version added | Enabled by default? |
| --- | --- | --- |
| Nightly | 111 | Yes |
| Developer Edition | 111 | Yes |
| Beta | 111 | Yes |
| Release | 102 | No |
| Preference name | `network.early-hints.enabled` |
### Access-Control-Allow-Headers wildcard does not cover Authorization
The `Access-Control-Allow-Headers` is a response header to a CORS preflight request, that indicates which request headers may be included in the final request.
The response directive can contain a wildcard (`*`), which indicates that the final request may include all headers except the `Authorization` header.
By default, Firefox includes the `Authorization` header in the final request after receiving a response with `Access-Control-Allow-Headers: *`.
Set the preference to `false` to ensure Firefox does not include the `Authorization` header.
For more details see Firefox bug 1687364.
| Release channel | Version added | Enabled by default? |
| --- | --- | --- |
| Nightly | 115 | Yes |
| Developer Edition | 115 | Yes |
| Beta | 115 | Yes |
| Release | 115 | Yes |
| Preference name | `network.cors_preflight.authorization_covered_by_wildcard` |
Developer tools
---------------
Mozilla's developer tools are constantly evolving. We experiment with new ideas, add new features, and test them on the Nightly and Developer Edition channels before letting them go through to beta and release. The features below are the current crop of experimental developer tool features.
### Execution context selector
This feature displays a button on the console's command line that lets you change the context in which the expression you enter will be executed. (See Firefox bug 1605154 and Firefox bug 1605153 for more details.)
| Release channel | Version added | Enabled by default? |
| --- | --- | --- |
| Nightly | 75 | No |
| Developer Edition | 75 | No |
| Beta | 75 | No |
| Release | 75 | No |
| Preference name | `devtools.webconsole.input.context` |
### Mobile gesture support in Responsive Design Mode
Mouse gestures are used to simulate mobile gestures like swiping/scrolling, double-tap and pinch-zooming and long-press to select/open the context menu. (See Firefox bug 1621781, Firefox bug 1245183, and Firefox bug 1401304 for more details.)
| Release channel | Version added | Enabled by default? |
| --- | --- | --- |
| Nightly | 76[1] | Yes |
| Developer Edition | 76[1] | Yes |
| Beta | 76[1] | Yes |
| Release | 76[1] | No |
| Preference name | n/a |
[1] Support for zooming using the double-tap gesture was added in Firefox 76. The other gestures were added for Firefox 79.
### Server-sent events in Network Monitor
The Network Monitor displays information for server-sent events. (See Firefox bug 1405706 for more details.)
| Release channel | Version added | Enabled by default? |
| --- | --- | --- |
| Nightly | 80 | Yes |
| Developer Edition | 80 | Yes |
| Beta | 80 | No |
| Release | 80 | No |
| Preference name | `devtools.netmonitor.features.serverSentEvents` |
### CSS browser compatibility tooltips
The CSS Rules View can display browser compatibility tooltips next to any CSS properties that have known issues. For more information see: Examine and edit HTML > Browser Compat Warnings.
| Release channel | Version added | Enabled by default? |
| --- | --- | --- |
| Nightly | 81 | No |
| Developer Edition | 81 | No |
| Beta | 81 | No |
| Release | 81 | No |
| Preference name | `devtools.inspector.ruleview.inline-compatibility-warning.enabled` |
UI
--
### Desktop zooming
This feature lets you enable smooth pinch zooming on desktop computers without requiring layout reflows, just like mobile devices do. (See Firefox bug 1245183 and Firefox bug 1620055 for more details.)
| Release channel | Version added | Enabled by default? |
| --- | --- | --- |
| Nightly | 42 | Yes |
| Developer Edition | 42 | No |
| Beta | 42 | No |
| Release | 42 | No |
| Preference name | `apz.allow_zooming` and (on Windows)
`apz.windows.use_direct_manipulation` |
See also
--------
* Firefox developer release notes
* Firefox Nightly
* Firefox Developer Edition |
Firefox 26 for developers - Mozilla | Firefox 26 for developers
=========================
Firefox 26 was released on December 10, 2013. This article lists key changes that are useful not only for web developers, but also Firefox and Gecko developers as well as add-on developers.
Changes for Web developers
--------------------------
### CSS
* The `text-decoration-line` property, still prefixed, now considers `'blink'` as a valid value, though it doesn't blink the content at all (Firefox bug 812995).
* The non-standard `-moz-text-blink` property has been removed (Firefox bug 812995).
* Support for the `image-orientation` property, in its CSS Images & Values Level 4 version, that is with the `from-image` keyword and EXIF support, has been added (Firefox bug 825771).
* Experimental support for `position: sticky` has been implemented and can be enabled by pref `layout.css.sticky.enabled` (Firefox bug 886646).
* The `text-align` property now applies to the `::-moz-placeholder` pseudo-element (Firefox bug 915551).
### HTML
* The `HTMLSelectElement.selectedOptions` property has been implemented (Firefox bug 596681).
* In the `<input>` element of type `email`, values with domain labels longer than 63 chars are no more considered valid (Firefox bug 884332).
* The `HTMLInputElement.width` and `height` properties now return `0` when the `type` is not `image` (Firefox bug 905240).
* A `<fieldset>` element is now invalid, and can be styled using the `:invalid` pseudo-class, when one of the elements it contains is invalid (Firefox bug 717181).
### JavaScript
ECMAScript 2015 implementation continues!
* The ECMAScript 2015 compliant syntax for Generators (yield) has been implemented (Firefox bug 666399).
* Generator/Iterator results are now boxed like `{ value: foo, done: bool }` (Firefox bug 907744).
* New mathematical methods have been implemented on `Math`: `Math.fround()` (Firefox bug 900125).
* The reserved words cannot be used for function names:such a usage now throws a `SyntaxError` (Firefox bug 907958).
* The default parameter syntax has been updated to allow parameters without defaults after default parameters, such as `function f(x=1, y)`. See Firefox bug 777060.
* `GeneratorFunction` is implemented (Firefox bug 904701).
### Interfaces/APIs/DOM
* Make the last argument (doctype) to `DOMImplementation.createDocument` optional (Firefox bug 909859).
* Implement the new `element.classList` specification which permits adding/removing several classes with one call (Firefox bug 814014).
* The `URL()` constructor has been implemented on the `URL` interface (Firefox bug 887364).
* The properties `URLUtils.origin`, `URLUtils.password`, and `URLUtils.username` are now available to all interfaces implementing the `URLUtils` mixin: `URL`, `Location`, `HTMLAnchorElement`, and `HTMLAreaElement` (Firefox bug 887364).
* The `URL` interface is now accessible from Web Workers (Firefox bug 887364).
* IndexedDB can now be used as an "optimistic" storage area so it doesn't require any prompts and data is stored in a pool with LRU eviction policy, in short temporary storage (Firefox bug 785884).
* Support for `WaveShaperNode.oversample` has been added (Firefox bug 875277).
* Path of the persistent storage has been changed from `<profile>/indexedDB` to `<profile>/storage/persistent` (on b2g from `/data/local/indexedDB` to `/data/local/storage/persistent`).
* The `Screen.orientation` property and `Screen.lockOrientation()` method now support the `default` value, mapping to `portrait-primary` or `landscape-primary`, depending of the device (Firefox bug 908058) This works only for Firefox OS and Firefox for Android. Firefox Desktop is not supported.
* `Event` constructors can be used in Web workers (Firefox bug 910910).
* Trying to set the `Document.domain` property on a page embedded in an `<iframe>` with the `sandbox` attribute now throws a security error (Firefox bug 907892).
* The `MessageEvent` interface has been updated to comply with the latest spec. The `initMessageEvent` method has been removed while the interface has now a constructor (Firefox bug 848294).
* The HTML5 `MessageChannel` API has been implemented, behind the `dom.messageChannel.enabled` preference (Firefox bug 677638).
* Support for `VTTCue`, behind the `media.webvtt.enabled` preference, like for all WebVTT-related implementations, has been added (Firefox bug 868509).
* The Web Audio API has been made available by default (Firefox bug 885505).
### MathML
* Inconsistent renderings of `<mmultiscripts>`, `<msub>`, `<msup>` and `<msubsup>` have been unified and the error handling of these elements has been improved (Firefox bug 827713).
### SVG
* The inclusion of SVG glyphs inside OpenType, *SVG-in-OpenType*, has been updated to match the current version of the specification (Firefox bug 906521).
* The `SVGElement.ownerSVGElement()` method doesn't throw anymore (Firefox bug 835048).
Development tools
-----------------
* The Inspector is now remotable (Firefox bug 805526).
* The web console text can be selected, `::before` and `::after` now inspectable, debugger and responsive design features are planned for this release. (https://hacks.mozilla.org/2013/09/new-features-in-the-firefox-developer-tools-episode-26/)
### Older versions
* Firefox 25 for developers
* Firefox 24 for developers
* Firefox 23 for developers
* Firefox 22 for developers
* Firefox 21 for developers
* Firefox 20 for developers
* Firefox 19 for developers
* Firefox 18 for developers
* Firefox 17 for developers
* Firefox 16 for developers
* Firefox 15 for developers
* Firefox 14 for developers
* Firefox 13 for developers
* Firefox 12 for developers
* Firefox 11 for developers
* Firefox 10 for developers
* Firefox 9 for developers
* Firefox 8 for developers
* Firefox 7 for developers
* Firefox 6 for developers
* Firefox 5 for developers
* Firefox 4 for developers
* Firefox 3.6 for developers
* Firefox 3.5 for developers
* Firefox 3 for developers
* Firefox 2 for developers
* Firefox 1.5 for developers |
Firefox 84 for developers - Mozilla | Firefox 84 for developers
=========================
This article provides information about the changes in Firefox 84 that will affect developers. Firefox 84 was released on December 15, 2020.
**Note:** See also And now for … Firefox 84 on Mozilla Hacks.
Changes for web developers
--------------------------
### Developer Tools
* The Firefox Accessibility Inspector now supports displaying the keyboard tab order on a web page. This provides a better high-level overview of how the page will be navigated using the keyboard than tabbing through the links (Firefox bug 1654956).
### HTML
*No changes.*
### CSS
* We've added support for complex selectors to the `:not` pseudo-class (Firefox bug 933562).
#### Removals
* We've removed the proprietary `-moz-default-appearance` property values `scrollbar-small` (`scrollbar-width: thin` is used instead) and `scrollbar` (macOS only; `scrollbar-horizontal` and `scrollbar-vertical` are used instead) (Firefox bug 1673132).
### JavaScript
* Custom date/time formats specified as options to the `Intl.DateTimeFormat()` constructor can now include `fractionalSecondDigits` — the number of digits used to represent fractions of a second (Firefox bug 1645107).
### HTTP
*No changes.*
### Security
* Firefox now ensures that `localhost` URLs — such as `http://localhost/` and `http://dev.localhost/` — refer to the local host's loopback interface (e.g. `http://127.0.0.1`). As a result, resources loaded from `localhost` are now assumed to have been delivered securely (see Secure contexts), and also will not be treated as mixed content (Firefox bug 1220810, Firefox bug 1488740).
### APIs
* We've added support for the `PerformancePaintTiming` interface of the Paint Timing API (Firefox bug 1518999).
* The `Navigator.registerProtocolHandler()` method now only accepts two parameters: `scheme` and `url`. `title` has been removed (Firefox bug 1631464).
#### Media, WebRTC, and Web Audio
* The `MediaRecorder.start()` method now throws an `InvalidModificationError` if the number of tracks on the stream being recorded has changed (Firefox bug 1581139).
#### Removals
* The application cache has been removed — developers should use the Service Worker API instead (Firefox bug 1619673).
### WebAssembly
*No changes.*
### WebDriver conformance (Marionette)
* Added chrome scope support for `WebDriver:PerformActions` and `WebDriver:ReleaseActions` (Firefox bug 1365886).
* The new Fission-compatible API has been enabled by default now. To revert to the former API the `marionette.actors.enabled` preference has to be set to `false` (Firefox bug 1669169).
* Fixed `WebDriver:SwitchToWindow` to always switch back to the top-level browsing context (Firefox bug 1305822).
* Improved browsing context checks for `WebDriver:SwitchToParentFrame` (Firefox bug 1671622).
* Fixed a hang for `WebDriver:Back` encountered when the currently-selected `<iframe>` gets unloaded (Firefox bug 1672758).
#### Known bugs
* After page navigation, accessing a previously-retrieved element might not always raise a "stale element" error, and can also lead to a "no such element" error. To prevent this, set the `marionette.actors.enabled` preference to `false` (Firefox bug 1684827).
Changes for add-on developers
-----------------------------
* The `browsingData.remove()` API now supports removing a subset of data types by `cookieStoreId`.
Older versions
--------------
* Firefox 83 for developers
* Firefox 82 for developers
* Firefox 81 for developers
* Firefox 80 for developers
* Firefox 79 for developers
* Firefox 78 for developers
* Firefox 77 for developers
* Firefox 76 for developers
* Firefox 75 for developers
* Firefox 74 for developers
* Firefox 73 for developers
* Firefox 72 for developers
* Firefox 71 for developers
* Firefox 70 for developers
* Firefox 69 for developers
* Firefox 68 for developers
* Firefox 67 for developers
* Firefox 66 for developers
* Firefox 65 for developers
* Firefox 64 for developers
* Firefox 63 for developers
* Firefox 62 for developers
* Firefox 61 for developers
* Firefox 60 for developers
* Firefox 59 for developers
* Firefox 58 for developers
* Firefox 57 for developers
* Firefox 56 for developers
* Firefox 55 for developers
* Firefox 54 for developers
* Firefox 53 for developers |
Firefox 116 for developers - Mozilla | Firefox 116 for developers
==========================
This article provides information about the changes in Firefox 116 that affect developers. Firefox 116 was released on August 01, 2023.
Changes for web developers
--------------------------
### HTML
* The `dirname` attribute is now supported on `input` and `textarea` elements.
This attribute allows for passing text directionality information (`ltr` or `rtl`) to the server during form submission (Firefox bug 675943).
### CSS
* The syntax has been updated for the `offset-path` property, which is used to define the path for an element to follow. The updated syntax allows you to set a value of `none` or one of `<offset-path>` or `<coord-box>`. The new `<offset-path>` value can be a `<ray()>`, a `<url>`, or a `<basic-shape>`. The `<coord-box>` value has replaced the older `<geometry-box>` value and lets you specify the shape of the path based on the element's box model. The `<basic-shape>` and `<coord-box>` values require the `layout.css.motion-path-basic-shapes.enabled` and `layout.css.motion-path-coord-box.enabled` preferences to be enabled, respectively. (Firefox bug 1598156) and (Firefox bug 1837305).
### Accessibility (ARIA)
* The `image` role is now supported as a synonym for `img`.
This maintains consistency with most role names which are complete words or concatenations of complete words (Firefox bug 1829269).
### JavaScript
* `Intl.NumberFormat` supports new constructor options that control how numbers are rounded (`roundingIncrement`, `roundingMode`, `roundingPriority`), the strategy for displaying trailing zeros on whole numbers (`trailingZeroDisplay`), and whether to use grouping separators to indicate thousands, millions, and so on (`useGrouping`).
It also supports new methods `formatRange()` amd `formatRangeToParts()` for formatting ranges of numbers.
(Firefox bug 1795756).
* `Intl.PluralRules` was updated (as part of the same set of changes as `Intl.NumberFormat`) to support constructor options `roundingIncrement`, `roundingMode`, `roundingPriority` and `trailingZeroDisplay`, and the `selectRange()` method.
(Firefox bug 1795756).
### SVG
* The `q` length unit (`1q = 1/40th of 1cm`) is now supported (Firefox bug 1836995).
### HTTP
* Configuring a Content-Security-Policy now supports specifying external JavaScript files to be whitelisted using hashes, where previously only inline scripts could be whitelisted using a hash (Firefox bug 1409200).
### APIs
#### DOM
* The `TextMetrics.fontBoundingBoxAscent` and `TextMetrics.fontBoundingBoxDescent` properties are now supported.
These metrics return, respectively, the distance above and below the `CanvasRenderingContext2D.textBaseline` to the bounding rectangle of all the fonts used to render the text (Firefox bug 1801198).
#### Media, WebRTC, and Web Audio
* The Audio Output Devices API is now supported on all platforms except for Android.
This API allows web applications to redirect audio output to a permitted Bluetooth headset, speakerphone, or other device, instead of having to use the browser or underlying OS default.
Affected APIs include `MediaDevices.selectAudioOutput()`, `MediaDevices.enumerateDevices()`, `HTMLMediaElement.setSinkId()`, `HTMLMediaElement.sinkId`, and the permission policy `Permissions-Policy: speaker-selection` (Firefox bug 1498512).
### WebDriver conformance (WebDriver BiDi, Marionette)
#### WebDriver BiDi
* Added support for the `session.end` command that allows users to terminate the automation session. This was previously only possible for sessions using both WebDriver Classic and WebDriver BiDi. It is now possible also for WebDriver BiDi-only sessions (Firefox bug 1829337).
* Added support for capability matching for the `session.new` command. It allows to define expectations about the target browser, such as browser name, platform name, etc. It can also be used to configure the session, for example, to specify if insecure certificates should be accepted (Firefox bug 1731730).
* Shadow roots are now correctly serialized when they are the root of a returned value (Firefox bug 1836514).
* The `network` event time origin information was renamed from `originTime` to `timeOrigin` (Firefox bug 1836926).
* The `network` event `network.responseCompleted` is now correctly emitted for navigation requests involving a redirect (Firefox bug 1838238).
#### Marionette
* Removed support for the `moz:useNonSpecCompliantPointerOrigin` capability. Users who still need this feature can still use the Firefox 115 ESR release as long as it is supported. Please file bugs under Remote Protocol :: Marionette if you're seeing any issue (Firefox bug 1490258).
* A regression was fixed that prevented us from differentiating stale elements (DOM elements that have been seen before on the page) from unknown elements for a given browsing context (Firefox bug 1822466).
* Creating a new session should now properly wait for the initial context to be loaded (Firefox bug 1838381).
Changes for add-on developers
-----------------------------
* The URL of a page visited when an extension is uninstalled, provided in `runtime.setUninstallURL`, can now be up to 1023 characters instead of 255 (Firefox bug 1835723).
* Adds `action.getUserSettings` providing the user-specified settings for an extension's browser action (Firefox bug 1814905).
* `autoDiscardable` is now supported in `tabs.Tab`, `tabs.onUpdated`, `tabs.update`, and `tabs.query` (Firefox bug 1809094).
Developer Tools
---------------
* Added support for Custom Formatters (Firefox bug 1752760).
* Added "container" badges in markup view on elements with a `container-type` property with `size` or `inline-size` values (Firefox bug 1789193).
* Fixed an issue in the Inspector where CSS custom properties set on the Custom Element Root were not displayed (Firefox bug 1836755).
* Show if request was resolved with DNS over HTTPS in Network Monitor (Firefox bug 1810195).
* Removed `Proxy-Authorization` header in Network Monitor (Firefox bug 1816115).
Older versions
--------------
* Firefox 115 for developers
* Firefox 114 for developers
* Firefox 113 for developers
* Firefox 112 for developers
* Firefox 111 for developers
* Firefox 110 for developers
* Firefox 109 for developers
* Firefox 108 for developers
* Firefox 107 for developers
* Firefox 106 for developers
* Firefox 105 for developers
* Firefox 104 for developers
* Firefox 103 for developers
* Firefox 102 for developers
* Firefox 101 for developers
* Firefox 100 for developers
* Firefox 99 for developers
* Firefox 98 for developers
* Firefox 97 for developers
* Firefox 96 for developers
* Firefox 95 for developers
* Firefox 94 for developers
* Firefox 93 for developers
* Firefox 92 for developers
* Firefox 91 for developers
* Firefox 90 for developers
* Firefox 89 for developers
* Firefox 88 for developers
* Firefox 87 for developers
* Firefox 86 for developers
* Firefox 85 for developers |
Firefox 7 for developers - Mozilla | Firefox 7 for developers
========================
Firefox 7 shipped on September 27, 2011. This article provides information about the changes that affect developers — both of web content and of Firefox add-ons.
Changes for web developers
--------------------------
### HTML
* The `HTMLHeadElement` `profile` property has been removed, this property has been deprecated since Gecko 2.0.
* The `HTMLImageElement` `x` and `y` properties have been removed.
* The `HTMLSelectElement` `add()` method `before` parameter is now optional.
* The `<body>` element's `background` attribute is no longer resolved as a URI; this is in compliance with the current HTML specification.
* The `<option>` element's `label` attribute now reflects the value of the element's text content if the attribute isn't specified.
#### Canvas
* As part of the Azure project the Direct2D Azure Backend has been implemented and will significantly improve the performance of the 2D canvas.
* Specifying invalid values when calling `setTransform()`, `bezierCurveTo()`, or `arcTo()` no longer throws an exception; these calls are now correctly silently ignored.
* The `isPointInPath()` method now correctly considers the transformation matrix when comparing the specified point to the current path.
* Calling `strokeRect()` with a zero width and height now correctly does nothing.
* Calling `drawImage()` with a zero width or height `<canvas>` now throws `INVALID_STATE_ERR`.
* Calling `drawImage()` with non-finite coordinates no longer throws an exception.
* `toDataURL()` method now accepts a second argument to control JPEG quality.
* Support for the non-standard `globalCompositeOperation` operations `clear` and `over` has been removed.
* Shadows are now only drawn for `source-over` compositing operations.
* You can now configure the fill rule used by canvas by setting the `mozFillRule` attribute on the context.
* Support for the experimental `mozDash`, `mozDashOffset`, `mozCurrentTransform` and `mozCurrentTransformInverse` attributes has been added.
* Support for the non-standard methods `mozDrawText()`, `mozMeasureText()`, `mozPathText()` and `mozTextAlongPath()` has been removed.
### CSS
* `text-overflow` is now supported.
* The `-moz-orient` property has been fixed so that `<progress>` elements that are vertically oriented have appropriate default dimensions.
### MathML
* XLink href has been restored and the MathML3 `href` attribute is now supported. Developers are encouraged to move to the latter syntax.
* Support for the `voffset` attribute on `<mpadded>` elements has been added and behavior of `lspace` attribute has been fixed.
* The top-level `<math>` element now accepts any attributes of the `<mstyle>` element.
* Support for Asana Math fonts has been added.
* The `medium` line thickness of fraction bars in `<mfrac>` elements has been corrected to match the default thickness.
* Names for negative spaces are now supported.
### DOM
* The `File` interface's non-standard methods `getAsBinary()`, `getAsDataURL()`, and `getAsText()` have been removed as well as the non-standard properties `fileName` and `fileSize` (Firefox bug 661876).
* The `FormData` interface no longer reports the filename as an empty string when sending the `Content-Disposition` HTTP header if the data was set using a `Blob`. This fixes errors that were happening with some servers.
* The `HTMLelement.dir` property now always returns its result as all lower-case, as required by the HTML specification.
* The `FileReader` `readAsArrayBuffer()` method is now implemented.
* `Document.createEntityReference` has been removed. It was never properly implemented and is not implemented in most other browsers.
* `document.normalizeDocument` has been removed. Use `Node.normalize` instead.
* `DOMTokenList.item` now returns `undefined` if the `index` is out of bounds, previously it returned `null`.
* `Node.getFeature` has been removed.
* The `HTMLInsElement` and `HTMLDelElement` interfaces have been removed, since the `<ins>` and `<del>` elements actually use the `HTMLModElement` interface.
* In an effort to conform to the upcoming DOM4 specification where `Attr` do not inherit from `Node` anymore (it did in DOM Core 1, 2 and 3), many `Node` properties and methods on the `Attr` interface are now reporting warnings as we work toward removing them in a later version.
* Added support for the `ondeviceorientation` and `ondevicemotion` properties on `window` objects.
* `window.resizeTo`, `window.resizeBy`, `window.moveTo`, and `window.moveBy` no longer apply to the main window.
### JavaScript
* The `Function.arity` property has been removed; use `Function.length` instead.
### WebSockets
* The `network.websocket.max-connections` preference is used to determine the maximum number of WebSocket connections that can be open at a time. The default value is 200.
* The underlying WebSocket protocol version 8 (as specified by IETF draft 10) is used now instead of the version 7 protocol used by Firefox 6.
* The WebSocket API is now available on Firefox Mobile.
### console API
* Message logged with `console.log` while the web console isn't open is still logged, although they aren't displayed when the web console is opened.
### Web timing
* Initial implementation of the Navigation Timing specification which provides data that can be used to measure the performance of a website.
### XML
* In addition to the previously supported `text/xsl`, XSLT stylesheets can now use the official internet media (MIME) type `application/xslt+xml` (in the stylesheet processing instruction or the HTTP Link header field).
Changes for Mozilla and add-on developers
-----------------------------------------
These changes affect add-on developers as well as developers working on or with Mozilla code itself. Add-on developers should see Updating extensions for Firefox 7 for additional information.
**Note:** Firefox 7 requires that binary components be recompiled, as do all major releases of Firefox.
### JavaScript code modules
#### FileUtils.jsm
* New method `openFileOutputStream()` opens a file output stream, the non-safe variant, for writing.
#### AddonManager.jsm
* The Add-on Manager has new methods for managing lists of add-ons that changed during application startup: `AddonManager.addStartupChange()`, `AddonManager.removeStartupChange()`, and `AddonManager.getStartupChanges()`.
### XUL
* `<tree>` elements can now persist the state of disclosure triangles if the nodes referenced by `datasources` all have unique IDs specified by "id" attributes.
* `<panel>` elements can now be configured to let the user drag them by clicking anywhere on their background by using the new `backdrag` attribute.
### XPCOM
* The new `Components.utils.schedulePreciseGC()` method lets you schedule a thorough garbage collection cycle to occur at some point in the future when no JavaScript code is executing; a callback is executed once collection is complete.
* The `Components.utils.unload()` method lets you unload JavaScript code modules previously loaded by calling `Components.utils.load()`.
### Memory reporters
Support has been added for multi-reporters; that is, memory reporters that gather data on request and call a callback for each generated result. See `nsIMemoryMultiReporter` and `nsIMemoryMultiReporterCallback` for the relevant interfaces, as well as the `nsIMemoryReporterManager.registerMultiReporter()` and `nsIMemoryReporterManager.unregisterMultiReporter()` methods.
### User experience changes
* Extension options can now be displayed inside the Add-on Manager for both restartless and traditional extensions.
* The destination of downloads is now remembered on a site-by-site basis. This data can be accessed using `DownloadLastDir.jsm`.
### Changes to the build system
* The ActiveX embedding API is no longer built and support has been removed from the build system. Supporting interfaces have also been removed; see Removed interfaces.
* You should no longer specify `-Zc:wchar_t-` when building on Windows.
### Interface changes
* `nsISocketTransport` now offers a new connection flag: `DISABLE_IPV6`; this causes a socket to only attempt to connect to IPv4 addresses, ignoring any available IPv6 addresses. In addition, `nsIDNSService` now offers a new resolve flag: `RESOLVE_DISABLE_IPV6`; this causes domain name resolution to only consider IPv4 hosts, ignoring any available IPv6 addresses. These changes are used to implement the "happy eyeballs" strategy for improving response time when attempting to connect on hosts that support both IPv4 and IPv6 (especially those that have broken IPv6 connectivity).
* `inIDOMUtils` has two new methods, `inIDOMUtils.getChildrenForNode()` which returns a list of child nodes of a node and `inIDOMUtils.getUsedFontFaces()` which returns a list of font faces used in a range.
* The `nsIMarkupDocumentViewer_MOZILLA_2_0_BRANCH` interface has been merged into the `nsIMarkupDocumentViewer` interface.
* The `nsIDOMWindow2` interface has been merged into the `nsIDOMWindow` interface.
* The `nsIDOMWindow_2_0_BRANCH` interface has been merged into the `nsIDOMWindowInternal` interface.
* `nsINavHistoryObserver` methods with URI parameters now require a GUID as well.
* The `nsISHistory_2_0_BRANCH` interface has been merged into the `nsISHistory` interface.
* `nsITelemetry` has a new method, `nsITelemetry.getHistogramById()` which returns a histogram by its ID, and a new attribute, `canRecord` which when set to `false` disables recording of telemetry statistics. Telemetry statistics are no longer recorded when in Private Browsing Mode. (see Firefox bug 661574 and Firefox bug 661573) Telemetry histograms defined with `nsITelemetry.newHistogram()` will not be reported in the telemetry ping.
* The `nsIMemoryReporter` interface has been substantially changed; if you use it, you will need to make some adjustments to your code.
* `nsIXMLHttpRequest`, headers set by `nsIXMLHttpRequest.setRequestHeader()` are sent with the request when following a redirect. Previously these headers would not be sent.
* `nsIDocShell` has a new `allowWindowControl` attribute. If `true`, the docshell's content is allowed to control the window (that is, to move or resize the window).
* The `nsIThreadInternal2` interface has been merged into the `nsIThreadInternal` interface.
#### New interfaces
`nsIDOMFontFace`
Describes a single font face.
`nsIDOMFontFaceList`
Describes a list of font faces, each represented by `nsIDOMFontFace`.
#### Removed interfaces
The following interfaces were implementation details that are no longer needed:
* `nsIDOM3Attr`
* `nsIDOM3Node`
* `nsIDOM3TypeInfo`
* `nsIDOM3Text`
* `nsIDOMDocumentStyle`
* `nsIDOMNSDocument`
* `nsIDOMNSFeatureFactory`
* `nsIDOMNSHTMLDocument`
* `nsIDOMNSHTMLFormElement`
* `nsIDOMNSHTMLHRElement`
* `nsIDOMNSHTMLTextAreaElement`
The following interfaces were removed as part of the removal of the ActiveX embedding API:
* `DITestScriptHelper`
* `DWebBrowserEvents`
* `DWebBrowserEvents2`
* `IDispatch`
* `IMozControlBridge`
* `IMozPluginHostCtrl`
* `IWebBrowser`
* `IWebBrowser2`
* `IWebBrowserApp`
* `IXMLDocument`
* `IXMLElement`
* `IXMLElementCollection`
* `IXMLError`
* `nsIActiveXSecurityPolicy`
* `nsIDispatchSupport`
* `nsIMozAxPlugin`
* `nsIScriptEventHandler`
* `nsIScriptEventManager`
### Other Changes
* The structure of the library window (`places.xul`) has been cleaned up. This may break extensions and themes.
* The look of the print preview window has been modernized and theme authors are encouraged to style it using the CSS pseudo-elements `::-moz-page`, `::-moz-page-sequence` and `::-moz-scrolled-page-sequence`.
See also
--------
* Firefox 6 for developers
* Firefox 5 for developers
* Firefox 4 for developers
* Firefox 3.6 for developers
* Firefox 3.5 for developers
* Firefox 3 for developers
* Firefox 2 for developers
* Firefox 1.5 for developers |
Firefox 17 for developers - Mozilla | Firefox 17 for developers
=========================
Firefox 17 shipped on November 20, 2012. This article lists key changes that are useful for not only web developers, but also Firefox and Gecko developers as well as add-on developers.
Changes for Web developers
--------------------------
### HTML
* Support for the `sandbox` attribute on the `<iframe>` element has been added. (Firefox bug 341604)
### CSS
* Support for `@supports` at-rule defined in CSS Conditional Rules Module Level 3 has been landed. It is disabled by default. Developers can try it by setting `layout.css.supports-rule.enabled` to true (bug 649740).
* Support for the CSS Selectors Level 4 pseudo-class `:dir()` allowing selection of elements based on their directionality has landed. (bug 562169)
* Support for the newly specified `isolate-override` value of the CSS `unicode-bidi` value has landed (Firefox bug 774335)
* Our prefixed implementation of `box-sizing` now takes into account `min-height` and `max-height`. One step closer to its unprefixing (Firefox bug 308801)
### DOM/APIs
* Support for `CSSSupportsRule` interface defined in CSS3 Conditional Rules specification has been landed (Firefox bug 649740)
* Support for `WheelEvent` object and `wheel` event have been landed (Firefox bug 719320).
* Support DOM Meta key on Linux again (Firefox bug 751749).
* On `HTMLMediaElement`, a new method, `mozGetMetadata`, that returns a JavaScript object whose properties represent metadata from the playing media resource as {key: value} pairs (Firefox bug 763010).
* Support for `Range.intersectsNode` has been added again; it has been removed in Gecko 1.9 (Firefox bug 579638.
* `Range.compareBoundaryPoints()` now throws a `DOMException` with the `NOT_SUPPORTED_ERR` value when the comparison method is invalid (Firefox bug 714279) .
* `Event.initEvent()` has been adapted to the spec: it doesn't throw anymore if called after the dispatch of the event, it is only a no-op (Firefox bug 768310).
* The non-standard `XMLHttpRequest.onuploadrequest` property has been removed (Firefox bug 761278).
* The method `XMLHttpRequest.getAllResponseHeaders()` now separates them with a CRLF (instead of a LF), as requested by the spec (Firefox bug 730925).
### JavaScript
* `String` object now offers Harmony `startsWith`, `endsWith`, and `contains` methods (Firefox bug 772733).
* The String methods link and anchor now escape the `'"'` (quotation mark) (Firefox bug 352437).
* Experimental support for strawman `ParallelArray` object has been implemented (Firefox bug 778559).
* Support to iterate `Map`/`Set` (Firefox bug 725909).
* Disabled EcmaScript for XML (E4X), an abandoned JavaScript extension, for web content by default (Firefox bug 778851).
* `__exposedProps__` must now be set for Chrome JavaScript objects exposed to content. Attempts to access Chrome objects from content without `__exposedProps__` set will fail silently (Firefox bug 553102).
* `for...of` loops now work in terms of `.iterator()` and `.next()` (Firefox bug 725907).
### WebGL
* The `EXT_texture_filter_anisotropic` WebGL extension has been unprefixed. Using `"MOZ_EXT_texture_filter_anisotropic"` will present a warning from now on. The prefixed name is going to be removed in a future release (Firefox bug 776001).
### SVG
*No change.*
### MathML
* The parsing of the `align` attribute on `<mtable>` elements has been updated to treat optional spaces more correctly.
### XUL
* XUL `key` element supports "os" modifier which is Win key (Super or Hyper key) (Firefox bug 778732).
### Network
* Removed the non-standard feature `XMLHttpRequest.onuploadprogress` which was deprecated in Firefox 14.
*No change.*
### Developer tools
* Change JSTerm's $ helper function from getElementById to querySelector() (Firefox bug 751749).
### User Agent
The Gecko part of the user agent string changed. The build date (which hadn't been updated since 2010) was removed, and the Gecko version number was put in its place instead. So `Gecko/20100101` -> `Gecko/17.0`. This may affect you if you are doing user agent sniffing.
Changes for add-on and Mozilla developers
-----------------------------------------
### Interface changes
`nsIInputStream`
The `available()` method returns 64-bit length instead of 32-bit (Firefox bug 215450).
`nsIDOMWindowUtils`
The `sendMouseScrollEvent()` method has been replaced with `sendWheelEvent()` (Firefox bug 719320).
`nsIFilePicker`
The `open()` method, to open the file dialog asynchronously, has been added and the `show()` method has been deprecated (Firefox bug 731307).
`nsIScriptSecurityManager`
The `checkLoadURIStr()` and `checkLoadURI()` methods have been removed (Firefox bug 327244).
`nsIRefreshURI`
The `setupRefreshURIFromHeader()` method has a `principal` parameter added (Firefox bug 327244).
#### New interfaces
None.
#### Removed interfaces
None removed.
See also
--------
* Firefox 17 Release Notes
* Aurora 17 is out, bringing better security and support for new standards (Mozilla Hacks)
* Add-on Compatibility for Firefox 17 (Add-ons Blog)
### Older versions
* Firefox 16 for developers
* Firefox 15 for developers
* Firefox 14 for developers
* Firefox 13 for developers
* Firefox 12 for developers
* Firefox 11 for developers
* Firefox 10 for developers
* Firefox 9 for developers
* Firefox 8 for developers
* Firefox 7 for developers
* Firefox 6 for developers
* Firefox 5 for developers
* Firefox 4 for developers
* Firefox 3.6 for developers
* Firefox 3.5 for developers
* Firefox 3 for developers
* Firefox 2 for developers
* Firefox 1.5 for developers |
Firefox 75 for developers - Mozilla | Firefox 75 for developers
=========================
This article provides information about the changes in Firefox 75 that will affect developers. Firefox 75 was released on April 7, 2020.
**See also the accompanying hacks post — Firefox 75: Ambitions for April.**
Changes for web developers
--------------------------
### Developer tools
* It is now possible to resize the rectangle of the Measuring Tool (Firefox bug 1152321).
* In the inspector, you can now use XPath expressions to locate elements, in addition to locating elements using CSS selectors as before (Firefox bug 963933).
* You can now filter WebSocket messages using regular expressions, in addition to plain text search, by writing the regular expression in slashes (Firefox bug 1593837).
### HTML
* The `loading` attribute of the `<img>` element has now been implemented. This string value can be used to specify that the image should be lazily loaded, by setting its value to `lazy` (Firefox bug 1542784).
* The value of the `<style>` element's `type` attribute is now restricted to `text/css` only, as per the spec (Firefox bug 1614329).
### CSS
* Support for the `min()`, `max()`, and `clamp()` functions has been implemented (Firefox bug 1519519).
* The `all` value of the `text-decoration-skip-ink` property has been added (Firefox bug 1611965)
### Accessibility
The new roles and objects related to ARIA annotations are now exposed in Firefox, on Windows and Linux (bear in mind that these still won't be usable until screen readers start to support them):
* `aria-description` (Firefox bug 1608961).
* `role="mark"` and `role="suggestion"` (Firefox bug 1608965).
* `role="comment"` (Firefox bug 1608969).
* Multiple IDs on `aria-details` (Firefox bug 1608883).
**Note:** On macOS, we are first waiting for Apple to define what Safari will expose as Apple-dialect attributes to VoiceOver, and will then follow suit.
### JavaScript
* Public static class fields are now supported (Firefox bug 1535804).
* The `Intl.Locale` class is now supported (Firefox bug 1613713).
* The `Function.caller` property has been updated to be aligned with the latest ECMAScript spec proposal. Previously throwing a `TypeError`, it now returns `null` if the caller is a strict, async, or generator function (Firefox bug 1610206).
### APIs
#### DOM
* The `HTMLFormElement` interface has a new method, `requestSubmit()`. Unlike the old (and still available) `submit()` method, `requestSubmit()` acts as if a specified submit button has been clicked, rather than just sending the form data to the recipient. Thus the `submit` event is delivered and the form is checked for validity prior to the data being submitted (Firefox bug 1613360).
* The `submit` event is now represented by an object of type `SubmitEvent` rather than a simple `Event`. `SubmitEvent` includes a new `submitter` property, which is the `Element` that was invoked to trigger the form submission. With this event, you can have a single handler for submit events that can discern which of multiple submit buttons or links was used to submit the form (Firefox bug 1588715).
* Calling the `click()` method on a detached element (one not part of a DOM tree) now functions normally, leading to a `click` event being sent to it (Firefox bug 1610821).
#### Web animations API
Firefox 75 sees numerous additions to the Web Animations API:
* Implicit to/from keyframes are now supported, as is automatically removing filling animations that have been replaced by other indefinitely filling animations (Firefox bug 1618773). This includes enabling of support for:
+ `Animation.commitStyles()`
+ `Animation.onremove`
+ `Animation.persist()`
+ `Animation.replaceState`
* The `Animation.timeline` getter, `Document.timeline`, `DocumentTimeline`, and `AnimationTimeline` features are now enabled by default (Firefox bug 1619178).
* The `Document.getAnimations()` and `Element.getAnimations()` methods are now enabled by default (Firefox bug 1619821).
#### Media, Web Audio, and WebRTC
* The `RTCPeerConnection.setLocalDescription()` method can now be called without arguments, in which case the WebRTC runtime will try to create the new local session description itself (Firefox bug 1568292).
### HTTP
*No changes.*
### Security
* CSP nonces from non-script sources, such as CSS selectors, and `.getAttribute("nonce")` calls, are now hidden. Instead, check the `.nonce` property to access nonces from scripts (Firefox bug 1374612).
### Plugins
*No changes.*
### WebDriver conformance (Marionette)
* Fixed a bug that always caused Marionette to initialize when Firefox starts-up. It has been limited to the command line argument and environment variable now (Firefox bug 1622012).
* Fixed `WebDriver:Print` to no longer add extra margins to the document (Firefox bug 1616932).
* Changed the preference value for `network.http.speculative-parallel-limit` to `0`, to no longer force-disable speculative connections (Firefox bug 1617869).
### Other
*No changes.*
Changes for add-on developers
-----------------------------
### API changes
* We've added some new settings in `browserSettings` (Firefox bug 1286953):
+ `browserSettings.zoomSiteSpecific` to control whether zooming is on a per-site or per-tab basis
+ `browserSettings.zoomFullPage` to control whether zoom is applied to the entire page or to text only.
* The name of the file used when saving a PDF with `tabs.saveAsPDF` can be specified using `toFileName` in the type `tabs.PageSettings`.(Firefox bug 1483590)
### Manifest changes
* The "privacy" permission is now optional. (Firefox bug 1618399)
Older versions
--------------
* Firefox 74 for developers
* Firefox 73 for developers
* Firefox 72 for developers
* Firefox 71 for developers
* Firefox 70 for developers
* Firefox 69 for developers
* Firefox 68 for developers
* Firefox 67 for developers
* Firefox 66 for developers
* Firefox 65 for developers
* Firefox 64 for developers
* Firefox 63 for developers
* Firefox 62 for developers
* Firefox 61 for developers
* Firefox 60 for developers
* Firefox 59 for developers
* Firefox 58 for developers
* Firefox 57 for developers
* Firefox 56 for developers
* Firefox 55 for developers
* Firefox 54 for developers
* Firefox 53 for developers
* Firefox 52 for developers
* Firefox 51 for developers
* Firefox 50 for developers
* Firefox 49 for developers
* Firefox 48 for developers
* Firefox 47 for developers
* Firefox 46 for developers
* Firefox 45 for developers
* Firefox 44 for developers |
Firefox 44 for developers - Mozilla | Firefox 44 for developers
=========================
To test the latest developer features of Firefox, install Firefox Developer EditionFirefox 44 was released on January 26, 2016. This article lists key changes that are useful not only for web developers, but also Firefox and Gecko developers as well as add-on developers.
Changes for Web developers
--------------------------
### Developer tools
Highlights:
* Memory tool
* Animation inspector improvements
* New Waterfall markers: DomContentLoaded, load, worker messages
All devtools bugs fixed between Firefox 43 and Firefox 44.
### HTML
* `<link rel="prefetch">` now obeys the `crossorigin` attribute (Firefox bug 1214819).
### CSS
* `position: fixed;` now always creates a new stacking context (Firefox bug 1179288).
* The support of `unicode-range` has been enabled by default (Firefox bug 1119062).
* Our experimental implementation of CSS Writing Modes has been updated to reflect the latest specification:
+ The value `sideways` of the `text-orientation` property has been implemented and `sideways-right` has been made an alias of it (Firefox bug 1193488).
+ The value `sideways-rl` and `sideways-lr` of the `writing-mode` property (Firefox bug 1193488 and Firefox bug 1193519).
* The non-standard properties `-moz-math-display` and `-moz-window-shadow` are no more available from Web content (Firefox bug 1207002, Firefox bug 1211040, and Firefox bug 1212607).
* The `font-style` property now distinguishes between `oblique` and `italic` when both variants are available (Firefox bug 543715).
* Though not supported, the properties `@page/marks`, `orphans`, `page`, `size`, and `widows`, were parsed and `@supports` was incorrectly reporting them as supported; this has been fixed and the properties are not parsed anymore, nor marked as supported (Firefox bug 1215702).
* The internal value `-moz-mac-unified-toolbar` has been removed from the possible values for the `appearance` property (Firefox bug 1206468).
* Several `-webkit` prefixed properties and values have been added for web compatibility, behind the preference `layout.css.prefixes.webkit`, defaulting to `false` (Firefox bug 837211):
+ `-webkit-animation`
+ `-webkit-animation-delay`
+ `-webkit-animation-direction`
+ `-webkit-animation-duration`
+ `-webkit-animation-fill-mode`
+ `-webkit-animation-iteration-count`
+ `-webkit-animation-name`
+ `-webkit-animation-play-state`
+ `-webkit-animation-timing-function`
+ `-webkit-text-size-adjust`
+ `-webkit-transform`
+ `-webkit-transform-origin`
+ `-webkit-transform-style`
+ `-webkit-transition`
+ `-webkit-transition-delay`
+ `-webkit-transition-duration`
+ `-webkit-transition-property`
+ `-webkit-transition-timing-function`
+ `-webkit-border-radius`
+ `-webkit-border-top-left-radius`
+ `-webkit-border-top-right-radius`
+ `-webkit-border-bottom-left-radius`
+ `-webkit-border-bottom-right-radius`
+ `-webkit-appearance`
+ `-webkit-background-clip`
+ `-webkit-background-origin`
+ `-webkit-background-size`
+ `-webkit-border-image`
+ `-webkit-box-shadow`
+ `-webkit-box-sizing`
+ `-webkit-user-select`
+ `-webkit-linear-gradient()` Firefox bug 1210575
+ `-webkit-radial-gradient"()` Firefox bug 1210575
+ `-webkit-repeating-linear-gradient()` Firefox bug 1210575
+ `-webkit-repeating-radial-gradient()` Firefox bug 1210575
### JavaScript
#### New APIs
* `Symbol.toPrimitive`, `Symbol.prototype[@@toPrimitive]`, and `Date.prototype[@@toPrimitive]` have been implemented (Firefox bug 1054756).
#### Changes
* The `let` and `const` bindings in the global level have been made compliant with ES2015 semantics. See Firefox bug 589199 and the blog post "Breaking changes in let and const in Firefox Nightly 44". In addition, `let` is now available to default Web JavaScript (strict and non-strict) and does not require a version opt-in anymore (Firefox bug 932517).
* If typed arrays' (like `Int8Array`) and `ArrayBuffer`) constructors are called as a function without the `new` operator, a `TypeError` is now thrown as per the ES2015 specification (Firefox bug 980945, Firefox bug 1214936).
* The `RegExp` sticky flag now follows the ES2015 standard for anchored sticky regular expressions (Firefox bug 773687).
* The JavaScript shell (SpiderMonkey's REPL) now defaults to the default, Web-compatible JS version (and not JS1.7+ anymore) (Firefox bug 1192329).
#### Removals
* Support for the non-standard `let` blocks has been dropped (Firefox bug 1167029.
* The non-standard and deprecated property `Object.prototype.__noSuchMethod__` has been removed (Firefox bug 683218).
### Interfaces/APIs/DOM
#### DOM & HTML DOM
* For compatibility with specific existing sites, the property `Document.charset` has been implemented as an alias of `Document.characterSet` (Firefox bug 647621).
* Support for the `window.sidebar.addSearchEngine()` method, which allowed Web pages to invoke an installation of a Sherlock plugin, has been dropped and now it just logs a warning in the Web Console (Firefox bug 862148).
* To fight unwanted pop-ups, prompts requested in `beforeunload` events of pages that have not been interacted with are no more displayed (Firefox bug 636905).
* The deprecated method `MessageEvent.initMessageEvent()` has been reimplemented for backward compatibility (Firefox bug 949376).
* The obsolete property `DocumentType.internalSubset` has been removed (Firefox bug 801545).
* For compatibility with existing sites, the properties `Window.orientation` and `Window.onorientationchange`, as well as the `orientationchange` event have been implemented (Firefox bug 920734).
* An `<iframe>` with explicit fullscreen request should not exit fullscreen implicitly (Firefox bug 1187801).
* The events `mouseover`, `mouseout`, `mouseenter`, `mouseleave`, `pointermove`, `pointerover`, `pointerout`, `pointerenter` and `pointerleave` are now triggered for disabled form elements (Firefox bug 218093).
* The method `Element.webkitMatchesSelector()` has been added (Firefox bug 1216193) to improve interoperability.
* To match the spec, the method `Document.createAttribute()` now converts the input to lower case (Firefox bug 1176313).
* The non-standard `dialog` feature for `Window.open()` is no longer available to Web content. It is still available to extensions and other code with chrome privileges (Firefox bug 1095236.
#### Canvas
* A new experimental `OffscreenCanvas` API that allows rendering contexts (such as WebGL) to run in Web Workers has been implemented. To use this experimental API set `gfx.offscreencanvas.enabled` to `true` in about:config (Firefox bug 709490). This API includes:
+ The `OffscreenCanvas` interface,
+ `HTMLCanvasElement.transferControlToOffscreen()`, and
+ `WebGLRenderingContext.commit()`.
+ Several WebGL interfaces are now also available in a worker context when this API is enabled.
#### WebGL
* Uniform Buffer Objects have been implemented (Firefox bug 1048747).
#### IndexedDB
* The `IDBIndex.getAll()` and `IDBIndex.getAllKeys()`, and there counterparts on `IDBObjectStore` are now available by default (Firefox bug 1196841).
#### Service Workers
* The `ServiceWorkerMessageEvent` and `ExtendableMessageEvent` interfaces have been implemented (Firefox bug 1143717 and Firefox bug 1207068).
* `Headers` objects now support a pair iterator, meaning that the methods `Headers.entries()`, `Headers.keys()`, and `Headers.values()` are now available; `Symbol.iterator` now also returns the default iterator for them (Firefox bug 1108181).
* The `XMLHttpRequest` API has been disabled on Service Workers (Firefox bug 931243).
* The interface `FetchEvent` now extends `ExtendableEvent`, giving it access to the `ExtendableEvent.waitUntil()` method. (Firefox bug 1214772).
* Following a recent change in the specification, `FetchEvent.client` has been removed (Firefox bug 1218135).
* To match the latest specification, the `ServiceWorkerContainer.onreloadpage` has been removed (Firefox bug 1218139).
* The event handlers `onbeforeevicted` and `onevicted` have been removed as they weren't following the spec. They will be reintroduced in the future, but their removal will allow feature detection to work as expected (Firefox bug 1218142).
* In the `FetchEvent()` constructor, if the `isReload` member is not present in the options dictionary, it now defaults to `false` (Firefox bug 1216401).
* The `Client.frameType` property is now implemented on the right interface; it was on `WindowClient` before (Firefox bug 1218146).
* When AppCache is used to provide offline support for a page, a warning message is now displayed in the console advising developers to use Service workers instead (Firefox bug 1204581.)
* Service workers have been enabled by default in Gecko.
#### WebRTC
* WebRTC interfaces have been *unprefixed* (Firefox bug 1155923). In particular:
+ `mozRTCPeerConnection` is now `RTCPeerConnection`.
+ `mozRTCIceCandidate` is now `RTCIceCandidate`.
+ `mozRTCSessionDescription` is now `RTCSessionDescription`.
* The `RTCDataChannel.bufferedAmountLowThreshold` property, as well as the `bufferedamountlow` event and its event handler, have been implemented (Firefox bug 1178091).
* The attribute `RTCPeerConnection.canTrickleIceCandidates` has been added, the non-standard method `RTCPeerConnection.updateIce()` removed (Firefox bug 1209744).
* The `MediaStream` interface now supports the `MediaStream.addTrack()` and `MediaStream.removeTrack()` methods (Firefox bug 1103188).
* The constructor `MediaStream()` has been implemented (Firefox bug 1070216).
* Support for the non-standard constraint style option list for `RTCOfferOptions` has been removed.
#### New APIs
* An experimental implementation of the Canvas API in Workers has landed: `OfflineCanvas` and `HTMLCanvasElement.transferControlToOffscreen()` are available behind the `gfx.offscreencanvas.enabled` preference, currently disabled by default (Firefox bug 709490).
* The Text2Speech API, part of Web Speech API, has now an OS X backend. But this is disabled by default (Firefox bug 1003452).
#### Miscellaneous
* `URLSearchParams` objects now support a pair iterator, meaning that the methods `URLSearchParams.entries()`, `URLSearchParams.keys()`, and `URLSearchParams.values()` are now available; `Symbol.iterator` now also returns the default iterator for them (Firefox bug 1085284).
* `FormData` objects now support a pair iterator, meaning that the methods `FormData.entries()`, `FormData.keys`, and `FormData.values()` are now available; `Symbol.iterator` now also returns the default iterator for them (Firefox bug 1127703).
* When `XMLHttpRequest.send()` is used with an HTML document, it now uses `text/html` instead of `application/xml` (Firefox bug 918771).
* Speech synthesis (text-to-speech) has been implemented in Firefox Desktop for Mac and Linux, hidden behind the `media.webspeech.synth.enabled` flag in `about:config` (Firefox bug 1003452, Firefox bug 1003464.) See Web Speech API for more information.
* Elements inside a `<frame>` or an `<object>` can't be set fullscreen anymore (Firefox bug 1212299).
* Sanitization of WOFF fonts is a bit more stricter, leading to more incorrect fonts being rejected, this sanitization is made a bit less stricter in Firefox 46 (Firefox bug 1193050 and Firefox bug 1244693).
### MathML
*No change.*
### SVG
*No change.*
### Audio/Video
*No change.*
HTTP
----
* Support for the Brotli algorithm has been added and both `Accept-Encoding` and `Content-Encoding` headers now support the `br` value (Firefox bug 366559 and Firefox bug 1211916).
* Incorrect support of HTTP/2 headers containing line breaks (`'/n'`) have been removed as the spec doesn't allow it, unlike HTTP/1 (Firefox bug 1197847).
Networking
----------
*No change.*
Security
--------
* RC4 is now also disabled by default on Beta and Release versions of the browser (Firefox bug 1201025) and the whitelist is now empty by default (Firefox bug 1215796).
Changes for add-on and Mozilla developers
-----------------------------------------
### Interfaces
*No change.*
### XUL
*No change.*
### JavaScript code modules
* Added `LIKE` support to Sqlite.jsm (Firefox bug 1188760).
* Added Snackbars.jsm module to Firefox for Android (Firefox bug 1215026)
### XPCOM
* The `nsIDOMWindow` interface is now empty. Its contents were either no longer used, had moved elsewhere, or were only used from C++. The items available from C++ code now reside in the nsPIDOMWindow interface (Firefox bug 1216401).
### Other
* Due to breaking changes in Firefox 44 (bug 1202902), add-ons packed with cfx will not work any longer. To make your add-on compatible again, please use jpm. You can find steps to migrate from *cfx* to *jpm* here.
Older versions
--------------
* Firefox 43 for developers
* Firefox 42 for developers
* Firefox 41 for developers
* Firefox 40 for developers
* Firefox 39 for developers
* Firefox 38 for developers
* Firefox 37 for developers
* Firefox 36 for developers
* Firefox 35 for developers
* Firefox 34 for developers
* Firefox 33 for developers
* Firefox 32 for developers
* Firefox 31 for developers
* Firefox 30 for developers
* Firefox 29 for developers
* Firefox 28 for developers
* Firefox 27 for developers
* Firefox 26 for developers
* Firefox 25 for developers
* Firefox 24 for developers
* Firefox 23 for developers
* Firefox 22 for developers
* Firefox 21 for developers
* Firefox 20 for developers
* Firefox 19 for developers
* Firefox 18 for developers
* Firefox 17 for developers
* Firefox 16 for developers
* Firefox 15 for developers
* Firefox 14 for developers
* Firefox 13 for developers |
Firefox 112 for developers - Mozilla | Firefox 112 for developers
==========================
This article provides information about the changes in Firefox 112 that affect developers. Firefox 112 was released on April 11, 2023.
Changes for web developers
--------------------------
### HTML
* The `HTMLElement` property **`inert`** is now fully enabled. It allows the browser to ignore content or interactive elements that are within an HTMLElement with the `inert` attribute. See Firefox bug 1764263 for more details.
### CSS
* The `overlay` keyword value for the `overflow` property is now supported as a legacy alias of the keyword value `auto` (Firefox bug 1817189).
* The `linear()` easing function is now supported.
This defines easing functions that interpolate linearly between a set of points and is useful for approximating complex animations (Firefox bug 1819447, Firefox bug 1764126).
### JavaScript
No notable changes.
### APIs
* `navigator.getAutoplayPolicy()` is now supported, allowing developers to configure autoplay of media elements and audio contexts based on whether autoplay is allowed, disallowed, or only allowed if the audio is muted.
See Firefox bug 1773551 for more details.
* Rounded rectangles can now be drawn in 2D canvases using `CanvasRenderingContext2D.roundRect()`, `Path2D.roundRect()` and `OffscreenCanvasRenderingContext2D.roundRect()`.
See Firefox bug 1756175 for more details.
* The deprecated and non-standard `CanvasRenderingContext2D.mozTextStyle` attribute is now disabled by default (Firefox bug 1818409).
#### Removals
* Removes support for `IDBMutableFile`, `IDBFileRequest`, `IDBFileHandle`, and `IDBDatabase.createMutableFile()`.
These interfaces are not present in any specification, have been behind a preference since version 102, and have been removed from the other main browser engines for some years.
(Firefox bug 1500343.)
### WebDriver conformance (WebDriver BiDi, Marionette)
#### WebDriver BiDi
* Implemented the `browsingContext.print` command, which allows clients to request a rendered PDF document of the browsing context, represented as a Base64-encoded string. See Firefox bug 1806810 for more details.
* Implemented `script.addPreloadScript` and `script.removePreloadScript` commands, which let test clients inject a functionality that's guaranteed to be available for any content scripts that are subsequently loaded, and before any later scripts that WebDriver injects into the context. See Firefox bug 1806420 and Firefox bug 1806465 for more details.
* `Element` and `ShadowRoot` references as stored in the node cache can now be used in both Marionette and WebDriver BiDi by their exact same unique reference. See Firefox bug 1770733 for more details.
* Removed `isRedirect` from the network events base parameters (Firefox bug 1819875).
#### Marionette
* Fixed an issue where the payload of a response was not wrapped within a `value` field based on certain data type. (Firefox bug 1819029).
* Fixed an issue where `WebDriver:ElementClear` was emitting an extra `change` event for content editable elements (Firefox bug 1744925).
Changes for add-on developers
-----------------------------
* The properties `usedDelegatedCredentials`, `usedEch`, `usedOcsp`, and `usedPrivateDns` have been added to `webRequest.SecurityInfo`. These properties provide information about the security of the connection used for a web request (Firefox bug 1804460).
* The property `"type"` is supported in the `"background"` manifest key. Setting this key to `"module"` loads background scripts specified with `"scripts"` as ES modules, avoiding the need to switch to background pages to use ES modules (Firefox bug 1811443).
Older versions
--------------
* Firefox 111 for developers
* Firefox 110 for developers
* Firefox 109 for developers
* Firefox 108 for developers
* Firefox 107 for developers
* Firefox 106 for developers
* Firefox 105 for developers
* Firefox 104 for developers
* Firefox 103 for developers
* Firefox 102 for developers
* Firefox 101 for developers
* Firefox 100 for developers
* Firefox 99 for developers
* Firefox 98 for developers
* Firefox 97 for developers
* Firefox 96 for developers
* Firefox 95 for developers
* Firefox 94 for developers
* Firefox 93 for developers
* Firefox 92 for developers
* Firefox 91 for developers
* Firefox 90 for developers
* Firefox 89 for developers
* Firefox 88 for developers
* Firefox 87 for developers
* Firefox 86 for developers
* Firefox 85 for developers
* Firefox 84 for developers
* Firefox 83 for developers
* Firefox 82 for developers
* Firefox 81 for developers |
Firefox 3 for developers - Mozilla | Firefox 3 for developers
========================
If you're a developer trying to get a handle on all the new features in Firefox 3, this is the perfect place to start. This article provides a list of the new articles covering features added to Firefox 3. While it doesn't necessarily cover every little change, it will help you learn about the major improvements.
New developer features in Firefox 3
-----------------------------------
### For website and application developers
Updating web applications for Firefox 3
Provides information about changes you may need to make to your website or web application to take advantage of new features in Firefox 3.
Online and offline events
Firefox 3 supports WHATWG online and offline events, which let applications and extensions detect whether or not there's an active Internet connection, as well as to detect when the connection goes up and down.
Web-based protocol handlers
You can now register web applications as protocol handlers using the `navigator.registerProtocolHandler()` method.
Drawing text using a canvas
You can now draw text in a canvas using a non-standardized API supported by Firefox 3.
Transform support for canvas
Firefox now supports the `transform()` and `setTransform()` methods on canvases.
Using microformats
Firefox now has APIs for working with microformats.
Drag and drop events
Firefox 3 supports new events that are sent to the source node for a drag operation when the drag begins and ends.
Focus management in HTML
The new HTML 5 `activeElement` and `hasFocus` attributes are supported.
Offline resources in Firefox
Firefox now lets web applications request that resources be cached to allow the application to be used while offline.
CSS improvements in Firefox 3
Firefox 3 features a number of improvements in its CSS support.
DOM improvements in Firefox 3
Firefox 3 offers a number of new features in Firefox 3's DOM implementation, including support for several Internet Explorer extensions to the DOM.
JavaScript 1.8 support
Firefox 3 offers JavaScript 1.8.
EXSLT support
Firefox 3 provides support for a substantial subset of the EXSLT extensions to XSLT.
SVG improvements in Firefox 3
SVG support in Firefox 3 has been upgraded significantly, with support for over two dozen new filters, several new elements and attributes, and other improvements.
Animated PNG graphics
Firefox 3 supports the animated PNG (APNG) image format.
### For XUL and extension developers
#### Notable changes and improvements
Updating extensions for Firefox 3
Provides a guide to the things you'll need to do to update your extension to work with Firefox 3.
XUL improvements in Firefox 3
Firefox 3 offers a number of new XUL elements, including new sliding scales, the date and time pickers, and spin buttons.
Templates in Firefox 3
Templates have been significantly improved in Firefox 3. The key improvement allows the use of custom query processors to allow data sources other than RDF to be used.
Securing updates
In order to provide a more secure add-on upgrade path for users, add-ons are now required to provide a secure method for obtaining updates before they can be installed. Add-ons hosted at AMO automatically provide this. Any add-ons installed that do not provide a secure update method when the user upgrades to Firefox 3 will be automatically disabled. Firefox will however continue to check for updates to the extension over the insecure path and attempt to install any update offered (installation will fail if the update also fails to provide a secure update method).
Places migration guide
An article about how to update an existing extension to use the Places API.
Download Manager improvements in Firefox 3
The Firefox 3 Download Manager features new and improved APIs, including support for multiple progress listeners.
Using nsILoginManager
The Password Manager has been replaced by the new Login Manager.
Embedding XBL bindings
You can now use the `data:` URL scheme from chrome code to embed XBL bindings directly instead of having them in separate XML files.
Localizing extension descriptions
Firefox 3 offers a new method for localizing add-on metadata. This lets the localized details be available as soon as the add-on has been downloaded, as well as when the add-on is disabled.
Localization and Plurals
Firefox 3 adds the new PluralForm module, which provides tools to aid in correctly pluralizing words in multiple localizations.
Theme changes in Firefox 3
Notes and information of use to people who want to create themes for Firefox 3.
#### New components and functionality
FUEL Library
FUEL is about making it easier for extension developers to be productive, by minimizing some of the XPCOM formality and adding some "modern" JavaScript ideas.
Places
The history and bookmarks APIs have been completely replaced by the new Places API.
Idle service
Firefox 3 offers the new `nsIIdleService` interface, which lets extensions determine how long it's been since the user last pressed a key or moved their mouse.
ZIP writer
The new `nsIZipWriter` interface lets extensions create ZIP archives.
Full page zoom
Firefox 3 improves the user experience by offering full page zoom in addition to text-only zoom.
Interfacing with the XPCOM cycle collector
XPCOM code can now take advantage of the cycle collector, which helps ensure that unused memory gets released instead of leaking.
The Thread Manager
Firefox 3 provides the new `nsIThreadManager` interface, along with new interfaces for threads and thread events, which provides a convenient way to create and manage threads in your code.
JavaScript modules
Firefox 3 now offers a new shared code module mechanism that lets you easily create modules in JavaScript that can be loaded by extensions and applications for use, much like shared libraries.
The `nsIJSON` interface
Firefox 3 offers the new `nsIJSON` interface, which offers high-performance encoding and decoding of JSON strings.
The `nsIParentalControlsService` interface
Firefox 3 now supports the Microsoft Windows Vista parental controls feature, and allows code to interact with it.
Using content preferences
Firefox 3 includes a new service for getting and setting arbitrary site-specific preferences that extensions as well as core code can use to keep track of their users' preferences for individual sites.
Plug-in Monitoring
A new component of the plugin system is now available to measure how long it takes plugins (e.g., Macromedia Flash) to execute their calls.
#### Fixed bugs
Notable bugs fixed in Firefox 3
This article provides information about bugs that have been fixed in Firefox 3.
New features for end users
--------------------------
### User experience
* **Easier password management.** An information bar at the top of the browser window now appears to allow you to save passwords after a successful login.
* **Simplified add-on installation.** You can now install extensions from third-party download sites in fewer clicks, thanks to the removal of the add-on download site whitelist.
* **New Download Manager.** The download manager makes it easier to locate your downloaded files.
* **Resumable downloads.** You can now resume downloads after restarting the browser or resetting your network connection.
* **Full page zoom.** From the View menu and using keyboard shortcuts, you can now zoom in and out on the content of entire pages — this scales not just the text but the layout and images as well.
* **Tab scrolling and quickmenu.** Tabs are easier to locate with the new tab scrolling and tab quickmenu features.
* **Save what you were doing.** Firefox 3 prompts you to see if you'd like to save your current tabs when you exit Firefox.
* **Optimized Open in Tabs behavior.** Opening a folder of bookmarks in tabs now appends the new tabs instead of replacing the existing ones.
* **Easier to resize location and search bars.** You can now easily resize the location and search bars using a simple resize handle between them.
* **Text selection improvements.** You can now select multiple ranges of text using the Control (Command on Macintosh) key. Double-clicking and dragging now selects in "word-by-word" mode. Triple-clicking selects an entire paragraph.
* **Find toolbar.** The Find toolbar now opens with the current selection.
* **Plugin management.** Users can now disable individual plugins in the Add-on Manager.
* **Integration with Windows Vista.** Firefox's menus now display using Vista's native theme.
* **Integration with Mac OS X.** Firefox now supports Growl for notifications of completed downloads and available updates.
* **Star button.** The new star button in the location bar lets you quickly add a new bookmark with a single click. A second click lets you file and tag your new bookmark.
* **Tags.** You can now associate keywords with your bookmarks to easily sort them by topic.
* **Location bar and auto-complete.** Type the title or tag of a page in the location bar to quickly find the site you were looking for in your history and bookmarks. Favicons, bookmark, and tag indicators help you see where the results are coming from.
* **Smart Bookmarks folder.** Firefox's new Smart Bookmarks folder offers quick access to your recently bookmarked and tagged places, as well as pages you visit frequently.
* **Bookmarks and History Organizer.** The new unified bookmarks and history organizer lets you easily search your history and bookmarks with multiple views and smart folders for saving your frequent searches.
* **Web-based protocol handlers.** Web applications, such as your favorite web mail provider, can now be used instead of desktop applications for handling `mailto:` links from other sites. Similar support is provided for other protocols as well. (Note that web applications do have to register themselves with Firefox before this will work.)
* **Easy to use Download Actions.** A new Applications preferences pane provides an improved user interface for configuring handlers for various file types and protocol schemes.
* **Improved look and feel.** Graphics and font handling have been improved to make websites look better on your screen, including sharper text rendering and better support for fonts with ligatures and complex scripts. In addition, Mac and Linux (Gnome) users will find that Firefox feels more like a native application for their platform than ever, with a new, native, look and feel.
* **Color management support.** By setting the `gfx.color_management.enabled` preference in `about:config`, you can ask Firefox to use the color profiles embedded in images to adjust the colors to match your computer's display.
* **Offline support.** Web applications can take advantage of new features to support being used even when you don't have an Internet connection.
### Security and privacy
* **One-click site information.** Want to know more about the site you're visiting? Click the site's icon in the location bar to see who owns it. Identify information is prominently displayed and easier than ever to understand.
* **Malware protection.** Firefox 3 warns you if you arrive at a website that is known to install viruses, spyware, trojans, or other dangerous software (known as malware).
* **Web forgery protection enhanced.** Now when you visit a page that's suspected of being a forgery, you're shown a special page instead of the contents of the page with a warning.
* **Easier to understand SSL errors.** The errors presented when an invalid SSL certificate is encountered have been clarified to make it easier to understand what the problem is.
* **Out-of-date add-on protection.** Firefox 3 now automatically checks add-on and plugin versions and disables older, insecure versions.
* **Secure add-on updates.** Add-on update security has been improved by disallowing add-ons that use an insecure update mechanism.
* **Anti-virus integration.** Firefox 3 now informs anti-virus software when executable files are downloaded.
* **Windows Vista parental controls support.** Firefox 3 supports the Vista system-wide parental control setting for disabling file downloads.
### Performance
* **Reliability.** Firefox 3 now stores bookmarks, history, cookies, and preferences in a transactionally secure database format. This means your data is protected against loss even if your system crashes.
* **Speed.** Firefox 3 has gotten a performance boost by completely replacing the part of the software that handles drawing to your screen, as well as to how page layout work is handled.
* **Memory use reduced.** Firefox 3 is more memory efficient than ever, with over 300 memory "leak" bugs fixed and new features to help automatically locate and dispose of leaked memory blocks.
See also
--------
* Firefox 2 for developers
* Firefox 1.5 for developers |
Firefox 13 for developers - Mozilla | Firefox 13 for developers
=========================
Firefox 13 was shipped on June 5, 2012. This page summarizes the changes in Firefox 13 that affect developers.
Changes for Web developers
--------------------------
### HTML
* Tables' `cellspacing` attributes are now parsed the same outside quirks mode as they are in quirks mode. That is, if a value is specified as a percentage, it's treated as a number of pixels instead, since percentage values are not actually permitted according to the specification.
* The `<wbr>` element has seen its bidirectional behavior fixed. It now behaves like the Unicode `U+200B ZERO-WIDTH SPACE` and therefore doesn't affect bi-directionality of its parent element anymore.
* The `:invalid` pseudo-class can now be applied to the `<form>` element.
### CSS
* The `turn` `<angle>` unit is now supported (to be used with CSS functions like `rotate()`).
* Support for 3-to-4 value syntax of the `background-position` has been added. You can offset a background image from any corner by writing like "`right 10px bottom 20px`". See Firefox bug 522607
* Support for the 2-value syntax of the CSS `background-repeat` has been added.
* Support for `-moz-border-radius*` and `-moz-box-shadow` has been removed. Authors should use unprefixed `border-radius` or `box-shadow` instead. See Firefox bug 693510
* The `column-fill` property has been implemented (prefixed).
### JavaScript
* Support for the ECMAScript 2015 `for...of` construct has been added.
* Experimental support for ECMAScript 2015 Map and Set objects has been implemented.
### DOM
* The `Node.cloneNode()` method's `deep` argument is now optional, as specified in DOM4.
* The `setTimeout()` and `setInterval()` methods no longer pass an additional "lateness" argument to the callback routine.
* The `Blob.mozSlice()` method has been unprefixed.
* Support for the `Blob` constructor has been added.
* Support for `globalStorage` has been removed.
* The new `DOMRequest` interface, used for reporting the status and result of background operations, has been added.
* The `HTMLOptionElement.index()` method now returns `0` instead of the incorrect `-1` when the `<option>` is inside a `<datalist>` HTML element.
* `DOMException` as defined in DOM Level 4 has been implemented.
* The `FileError` interface has been removed in favor of the `DOMError` interface as defined in the latest FileAPI specification.
* The `Range` object no longer throws a `RangeException`. Instead a `DOMException` as defined in DOM 4 is used.
* `element.getAttributeNS()` now always returns `null` instead of the empty string for non-existent attributes. Previously, there were cases in which the empty string could be returned. This is in keeping with the DOM4 specification, which now says this should return null for non-existent attributes, instead of an empty string.
* The `HTMLCanvasElement` interface now has a non-standard `mozFetchAsStream()` method, which provides an input stream containing the element's image data in the specified format.
### UA string
* Firefox for Android now has a Tablet or Mobile token in the UA string to indicate the form factor and no longer has the Fennec token. Also, the number after "Gecko/" is now the Gecko version number instead of a frozen date.
* The UA string no longer exposes the Gecko patch number or release status in the version number; that is, the version number is now always of the form "X.Y", where X is the major release number and Y the minor. For example, "13.0" or "14.1". It will no longer be something like "14.0.1b1".
### SVG
* The `SVGStringList` DOM interface is now indexable like `Array` (see Firefox bug 722071).
### WebGL
* Support has been added for the `EXT_texture_filter_anisotropic` extension. Anisotropic texture filtering improves the quality of mipmapped texture access when viewing a textured primitive at an oblique angle.
### MathML
* Support for the `width` attribute on `<mtable>` elements has been added (Firefox bug 722880).
* MathJax fonts are now used as the default fonts for mathematical text. See Fonts for Mozilla's MathML engine for more information.
### Network
* The SPDY protocol now enabled by default.
### Developer tools
#### 3D view improvements
* You can now press the "f" key to make sure the currently selected node is visible.
#### Style panel improvements
* Clicking the heading for any rule in the style panel now opens the Style Editor at the corresponding CSS.
* Right-clicking on a rule in the style panel now offers an option to copy the rule to the clipboard.
* Entering an unknown property name, or an illegal property value, displays a warning icon next to that property.
#### Scratchpad improvements
* The *Scratchpad* now has an option in the Help menu to take you to the MDN documentation about Scratchpad.
Changes for Mozilla and add-on developers
-----------------------------------------
### Compatibility note
Starting in Firefox 13, Firefox for Windows requires at least Windows XP Service Pack 2; it will no longer run on Windows 2000 or earlier versions of Windows XP.
### JavaScript code modules
#### source-editor.jsm
* Support for a dirty flag has been added to the Source Editor API.
* The Source Editor no longer supports falling back to a `<textarea>` instead of using Orion.
* The editor now exposes focus and blur events.
* The `getIndentationString()` method has been added; this returns the string to use for indenting text in the editor.
* The Source Editor now supports managing a list of breakpoints and displaying user interface for toggling them on and off; it does not actually implement breakpoints, however. That's up to you to write debugger code for.
* Support has been added for highlighting the current line, using the `highlightCurrentLine` configuration option.
### ARIA
* The CSS properties `margin-left`, `margin-right`, `margin-top`, `margin-bottom` are now all reflected into ARIA object attributes with the same name. See Gecko object attributes for more information.
### Interfaces
* The `nsIScreen` interface now supports controlling rotation through the new `rotation` attribute.
* The `nsIPrefBranch2` interface has been merged into `nsIPrefBranch` (Firefox bug 718255).
* The new message manager wake-up service, implemented by `nsIMessageWakeupService`, has been implemented. See Firefox bug 591052.
* The aliases `MozOpacity`, `MozOutline`, `MozOutlineStyle`, `MozOutlineWidth`, `MozOutlineOffset`, and `MozOutlineColor`, all of which were removed in previous versions of Gecko, have been removed from `nsIDOMCSS2Properties`, which should have been done with the aliases were initially removed.
* The `nsINavHistoryQueryOptions` attribute `excludeItemIfParentHasAnnotation` has been removed, along with the corresponding query operation. It existed to support livemarks, which no longer exist.
See also
--------
* Firefox 12 for developers
* Firefox 11 for developers
* Firefox 10 for developers
* Firefox 9 for developers
* Firefox 8 for developers
* Firefox 7 for developers
* Firefox 6 for developers
* Firefox 5 for developers
* Firefox 4 for developers
* Firefox 3.6 for developers
* Firefox 3.5 for developers
* Firefox 3 for developers
* Firefox 2 for developers
* Firefox 1.5 for developers |
Firefox 58 for developers - Mozilla | Firefox 58 for developers
=========================
This article provides information about the changes in Firefox 58 that will affect developers. Firefox 58 was released on January 23, 2018.
Changes for Web developers
--------------------------
### Developer Tools
* The Shape Path Editor has been enabled by default for shapes generated via `clip-path` (Firefox bug 1405339).
* The Network Monitor now has a button to pause/play recording of network traffic (Firefox bug 1005755).
* In the Network Monitor the "Flash" filter button is no longer available, and Flash requests are included in the "Others" filter (Firefox bug 1413540).
* The code for the old Responsive Design Mode (enabled by default pre-Firefox 52) has now been removed from the Devtools (Firefox bug 1305777). See Responsive Design Mode for information on the new tools.
* The option to view MDN docs from the CSS pane of the page inspector has been removed (Firefox bug 1382171) (was disabled since 55, Firefox bug 1352801).
### HTML
*No changes.*
### CSS
* The `font-display` descriptor is now available by default on all platforms (Firefox bug 1317445).
### SVG
*No changes.*
### JavaScript
* The `Promise.prototype.finally()` method has been implemented (Firefox bug 1019116).
* The `Intl.PluralRules` object has been implemented (Firefox bug 1403318).
* The `Intl.NumberFormat.prototype.formatToParts()` method has been implemented (Firefox bug 1403319).
* The `Intl.DateTimeFormat` object now supports the `hourCycle` option and the `hc` language tag (Firefox bug 1386146).
* The optional catch binding proposal has been implemented (Firefox bug 1380881).
### APIs
#### New APIs
* The `PerformanceNavigationTiming` API has been implemented (Firefox bug 1263722).
+ Gecko has also been given a pref that can be used to disable the interface if required — `dom.enable_performance_navigation_timing`, defaulting to `true` (Firefox bug 1403926).
#### DOM
* Errors reported via error objects in certain APIs — for example in the `error` property of `FileReader`, `IDBRequest`, and `IDBTransaction`, and when requests made via certain methods of `RTCPeerConnection` are unsuccessful — are now represented by `DOMException` instances. `DOMError` is now deprecated, having been removed from the DOM4 spec (Firefox bug 1120178).
* The `PerformanceResourceTiming.workerStart` property is now supported (Firefox bug 1191943).
* Budget-based background timeout throttling has been implemented — see Policies in place to aid background page performance for more details (Firefox bug 1377766).
#### DOM events
*No changes.*
#### Media and WebRTC
* The prefixed version of `HTMLMediaElement.srcObject` has been removed; make sure code is updated to use the standard `srcObject` instead of `mozSrcObject` (Firefox bug 1183495).
* Using `MediaStream.addTrack()` to add tracks to a stream obtained using `getUserMedia()`, then attempting to record the resulting stream now works as expected. Previously, only the tracks originally included in the stream returned by `getUserMedia()` were being included in the recorded media (Firefox bug 1296531).
* The WebVTT `VTTRegion` interface has always been created when interpreting WebVTT files, but the resulting regions were not previously utilized. Starting in Firefox 58, they are, if you enable the preference `media.webvtt.regions.enabled` by setting its value to `true`.
#### Canvas and WebGL
* Support for prefixed WebGL extensions has been removed (Firefox bug 1403413):
+ For `MOZ_WEBGL_compressed_texture_atc` use `WEBGL_compressed_texture_atc` instead.
+ For `MOZ_WEBGL_compressed_texture_pvrtc` use `WEBGL_compressed_texture_pvrtc` instead.
+ For `MOZ_WEBGL_compressed_texture_s3tc` use `WEBGL_compressed_texture_s3tc` instead.
+ For `MOZ_WEBGL_depth_texture` use `WEBGL_depth_texture` instead.
+ For `MOZ_WEBGL_lose_context` use `WEBGL_lose_context` instead.
### HTTP
* `frame-ancestors` is no longer ignored in `Content-Security-Policy-Report-Only` (Firefox bug 1380755).
* Firefox now implements a TLS handshake timeout with a default value of 30 seconds. The timeout value can be varied by editing the `network.http.tls-handshake-timeout` pref in about:config (Firefox bug 1393691).
* The `worker-src` CSP directive has been implemented (Firefox bug 1302667).
* The 425: Too Early status code and related `Early-Data` request header are now supported (Firefox bug 1406908).
### Security
*No changes.*
### Plugins
*No changes.*
### Other
* "Add to home screen" is now supported in Firefox for Android, part of the Progressive Web Apps effort (Firefox bug 1212648).
* WebAssembly now has a tiered compiler providing load time optimizations (Firefox bug 1277562), and new streaming APIs — `WebAssembly.compileStreaming()` and `WebAssembly.installStreaming()` Firefox bug 1347644.
Removals from the web platform
------------------------------
### HTML
* You can no longer nest an `<a>` element inside a `<map>` element to create a hotspot region — an `<area>` element needs to be used instead (Firefox bug 1317937).
### CSS
* The following proprietary Mozilla system metric pseudo-classes are no longer available to web content (Firefox bug 1396066):
+ `:-moz-system-metric(images-in-menus)`
+ `:-moz-system-metric(mac-graphite-theme)`
+ `:-moz-system-metric(scrollbar-end-backward)`
+ `:-moz-system-metric(scrollbar-end-forward)`
+ `:-moz-system-metric(scrollbar-start-backward)`
+ `:-moz-system-metric(scrollbar-start-forward)`
+ `:-moz-system-metric(scrollbar-thumb-proportional)`
+ `:-moz-system-metric(touch-enabled)`
+ `:-moz-system-metric(windows-default-theme)`
* The following proprietary Mozilla media features are no longer available to web content (Firefox bug 1396066):
+ `-moz-color-picker-available`
+ `-moz-is-glyph`
+ `-moz-mac-graphite-theme`
+ `-moz-mac-yosemite-theme`
+ `-moz-os-version`
+ `-moz-overlay-scrollbars`
+ `-moz-physical-home-button`
+ `-moz-scrollbar-end-backward`
+ `-moz-scrollbar-end-forward`
+ `-moz-scrollbar-start-backward`
+ `-moz-scrollbar-start-forward`
+ `-moz-scrollbar-thumb-proportional`
+ `-moz-swipe-animation-enabled`
+ `-moz-windows-accent-color-in-titlebar`
+ `-moz-windows-classic`
+ `-moz-windows-compositor`
+ `-moz-windows-default-theme`
+ `-moz-windows-glass`
+ `-moz-windows-theme`
* The proprietary Mozilla `:-moz-styleeditor-transitioning` pseudo-class is no longer available to web content (Firefox bug 1396099).
### JavaScript
* The non-standard `Date.prototype.toLocaleFormat()` method has been removed (Firefox bug 818634).
* The non-standard and deprecated `Object.prototype.watch()` and `unwatch()` methods have been removed and will no longer work (Firefox bug 638054). Consider using setters and getters or proxies instead.
* The legacy Iterator protocol, the `StopIteration` object, the legacy generator functions and the non-standard `Function.prototype.isGenerator()` method have been removed. Use the ES2015 iteration protocols and standards-compliant iterators and generators instead (Firefox bug 1083482, Firefox bug 1413867, Firefox bug 1119777).
* The non-standard Array comprehensions and Generator comprehensions have been removed (Firefox bug 1414340).
### APIs
* The proprietary `moz-blob` and `moz-chunked-text` values of the `XMLHttpRequest.responseType` property were removed completely in Firefox 58 (Firefox bug 1397145, Firefox bug 1397151, Firefox bug 1120171).
* The `dom.abortController.enabled` and `dom.abortController.fetch.enabled` prefs that controlled exposure of the Abort API functionality have now been removed, since those features are now enabled by default (Firefox bug 1402317).
* The proprietary `mozSrcObject` property was removed in Firefox 58 (Firefox bug 1183495). Use the standard `HTMLMediaElement.srcObject` property instead.
### SVG
*No changes.*
Changes for add-on and Mozilla developers
-----------------------------------------
### WebExtensions
* browserSettings
+ browserSettings.webNotificationsDisabled has been implemented (bug 1364942)
* browsingData
+ browsingData.localStorage now supports deleting localStorage by host (bug 1388428)
* pkcs11 API to manage security devices (Bug 1357391)
* privacy
+ first party isolation can now be toggled though firstPartyIsolate (bug 1409045)
+ resist fingerprinting pref can now be toggle through resistFingerprinting (bug 1397611)
* tabs
+ tabs.discard has been implemented (Bug 1322485)
+ isArticle, isInReaderMode properties of Tab implemented (Bug 1381992)
+ toggleReaderMode() method implemented (Bug 1381992)
+ openInReaderMode option of tabs.created implemented (Bug 1408993)
+ tabs.onUpdated now notifies when entering/exiting reader mode (Bug 1402921)
* theme
+ getCurrent() method to obtain current theme properties (Bug 1349944)
+ onUpdated method to receive WebExtension theme updates (Bug 1349944)
+ colors.bookmark\_text now supported as alias of colors.toolbar\_text (Bug 1412595)
+ colors.toolbar\_top\_separator, colors.toolbar\_bottom\_separator and colors.toolbar\_vertical\_separator implemented (Bug 1347190)
* webRequest
+ webRequest.onBeforeRequest now includes a "frameAncestors" parameter
Older versions
--------------
* Firefox 57 for developers
* Firefox 56 for developers
* Firefox 55 for developers
* Firefox 54 for developers
* Firefox 53 for developers
* Firefox 52 for developers
* Firefox 51 for developers
* Firefox 50 for developers
* Firefox 49 for developers
* Firefox 48 for developers
* Firefox 47 for developers
* Firefox 46 for developers
* Firefox 45 for developers
* Firefox 44 for developers
* Firefox 43 for developers
* Firefox 42 for developers
* Firefox 41 for developers
* Firefox 40 for developers
* Firefox 39 for developers
* Firefox 38 for developers
* Firefox 37 for developers
* Firefox 36 for developers
* Firefox 35 for developers
* Firefox 34 for developers
* Firefox 33 for developers
* Firefox 32 for developers
* Firefox 31 for developers
* Firefox 30 for developers
* Firefox 29 for developers
* Firefox 28 for developers
* Firefox 27 for developers |
Firefox 69 for developers - Mozilla | Firefox 69 for developers
=========================
This article provides information about the changes in Firefox 69 that will affect developers. Firefox 69 was released on September 3, 2019.
Changes for web developers
--------------------------
### Developer tools
#### Debugger
* Event Listener Breakpoints let you diagnose which code a page executes in response to browser events. You can pick specific types, such as `click` or `keydown`, or whole categories of events, like all mouse input events. (Firefox bug 1526082).
* Scripts shown in the debugger's source list pane can now be saved via the *Download file* context menu option (Firefox bug 888161).
* In the debugger's source list pane, loaded extensions are listed with their name, rather than just their UUID (Firefox bug 1486416), making it much easier to find the extension code you want to debug.
* The debugger now loads significantly faster via lazy-loading scripts (Firefox bug 1527488).
#### Console
* Browser Console messages from tracking protection errors, CSP errors, and CORS errors are grouped automatically to reduce noise from repeated blocked resources and storage access (Firefox bug 1522396).
* All visible logs in the console can shared by saving to a file or copying to clipboard via a new *Export visible messages to* context menu item (Firefox bug 1517728).
* The console's toolbar now responsively reduces its height into a single row to save vertical space (Firefox bug 972530).
* Messages from content can now be hidden in the console to focus on logs from the Firefox UI (Firefox bug 1523842).
#### Network
* Resources that got blocked because of CSP or Mixed Content are now shown in the Network panel, with details of the reason (Firefox bug 1556451).
* A new optional *URL* column in the Network panel can be enabled to show the full URL for resources (Firefox bug 1341155).
#### Inspector
* When you hover over an element in the Page Inspector, the infobar that appears now includes the fact that an element is a flex container, or flex item (Firefox bug 1521188).
* When inspecting a page containing a grid with a subgrid, the parent grid's overlay lines are displayed whenever the subgrid's lines are displayed; if the parent grid's overlay checkbox is unselected, then its lines are translucent (Firefox bug 1550519).
#### Remote debugging
* For our mobile web developers, we have migrated remote debugging from the old WebIDE into a re-designed about:debugging, making the experience of debugging GeckoView on remote devices via USB much better (Firefox bug 1462208).
#### General
* The DevTools panel order has been changed to reflect popularity (Firefox bug 1558630).
### HTML
* In order to align more closely to the specification, the text track associated with a `<track>` element no longer loads the WebVTT file containing the text cues if the element is created in its default `disabled` `mode`. To access or manipulate the cues when the `mode` is `disabled`, change the `mode` to either `started` or `hidden`; this will trigger loading of the WebVTT data (Firefox bug 1550633).
#### Removals
* The HTML `<keygen>` element has been removed from Firefox. It was deprecated some time ago, and its purpose has generally been supplanted by other technologies (Firefox bug 1315460).
### CSS
* We implemented the `break-spaces` value of the `white-space` property (Firefox bug 1351432).
* The SVG geometry attributes (such as `width` and `height`) can now also be defined as CSS properties (Firefox bug 1383650).
* The `::cue` selector — used to style the captions ("cues") displayed by WebVTT — now enforces the limitations on which CSS properties may be used within cues, as per the specification (Firefox bug 1321488).
* We've restricted the properties that may apply to `::marker` as per the specification (Firefox bug 1552578)
* The `overflow-block` and `overflow-inline` properties have been implemented (Firefox bug 1470695).
* We added the ability to test for support of a selector when using CSS Feature Queries (`@supports`), with the `selector()` method (Firefox bug 1513643).
* The `user-select` property — which specifies whether or not the user is able to select text in the affected element — has been unprefixed (Firefox bug 1492739).
* We implemented local-specific casing behavior for Lithuanian (Firefox bug 1322992), as seen in this example.
* We've implemented the `line-break` property of CSS Text (Firefox bug 1011369 and Firefox bug 1531715).
* The `contain` property — which allows developers to define that an element and its contents are mostly independent of the rest of the DOM tree — got implemented Firefox bug 1487493.
### SVG
* We've added support for gzip-compressed SVG-in-OpenType (Firefox bug 1359240).
* The `SVGGeometryElement.isPointInFill()` and `SVGGeometryElement.isPointInStroke()` methods have been implemented (Firefox bug 1325319).
### JavaScript
* Public class fields are enabled by default (Firefox bug 1555464). See also Class fields for more information.
* The promise rejection events `unhandledrejection` and `rejectionhandled` are now enabled by default (Firefox bug 1362272). To learn more about how these work, see Promise rejection events.
### HTTP
* The HTTP headers `Access-Control-Expose-Headers`, `Access-Control-Allow-Methods`, and `Access-Control-Allow-Headers` now accept a wildcard value "`*`" for requests without credentials (Firefox bug 1309358). This change has also been uplifted to Firefox 68 ESR.
### APIs
#### New APIs
* The Resize Observer API is supported by default (Firefox bug 1543839).
* The Microtask API (`queueMicrotask()`) has been implemented (Firefox bug 1480236).
#### DOM
* The `DOMMatrix`, `DOMPoint`, and related objects are now supported in workers (Firefox bug 1420580).
* The `pageX` and `pageY` properties have been moved from `UIEvent` to `MouseEvent`, for better spec compliance (Firefox bug 1178763). These properties are no longer exposed to the `CompositionEvent`, `FocusEvent`, `InputEvent`, `KeyboardEvent`, and `TouchEvent` interfaces, which all inherit from `UIEvent`.
* The `Blob.text()`, `Blob.arrayBuffer()`, and `Blob.stream()` methods are now implemented (Firefox bug 1557121).
* `DOMMatrix.fromMatrix()` has been implemented (Firefox bug 1560462).
* We now support the six-parameter version of the `DOMMatrix.scale()` method (Firefox bug 1397945).
* The arguments for `DOMMatrix.translate()`, `DOMMatrix.skewX()`, and `DOMMatrix.skewY()` are now all optional, as per spec (Firefox bug 1397949).
* The `Navigator.userAgent`, `Navigator.platform`, and `Navigator.oscpu` properties no longer reveal whether a user is running 32-bit Firefox on a 64-bit OS (Firefox bug 1559747). They now say `Linux x86_64` instead of `Linux i686 on x86_64`, and `Win64` instead of `WOW64`.
* The remaining methods of `HTMLDocument` have been moved to `Document`. This should have no appreciable impact on your work in most cases. In particular, the `close()`, `open()`, and `write()` methods have been moved. So have the various editor related methods, including `execCommand()` as well as various properties (Firefox bug 1549560).
* We have implemented `AbstractRange` and `StaticRange` (Firefox bug 1444847).
#### Media, Web Audio, and WebRTC
* For improved user security, and in-keeping with the latest versions of the Media Capture and Streams specification, the `navigator.mediaDevices` property is no longer present if the context is insecure. To use `getUserMedia()`, `getDisplayMedia()`, `enumerateDevices()`, and so forth, be sure your content is loaded using HTTPS (Firefox bug 1528031).
* The Web Audio API's `AudioParam.value` property now returns the actual value of the property at the current time, taking into account all scheduled or graduated value changes. Previously, Firefox only returned the most recent explicitly-set value (as through using the `value` setter) (Firefox bug 893020).
* We've updated `MediaStreamAudioSourceNode` to use the new, lexicographical, ordering for tracks. Previously, track ordering was up to the individual browser, and could even change arbitrarily. In addition, attempting to create a `MediaStreamAudioSourceNode` using a stream that has no audio tracks now throws an `InvalidStateError` exception (Firefox bug 1553215).
* The `facingMode`, `deviceId`, and `groupId` settings are now included as members of the `MediaTrackSettings` object returned by calls to `MediaStreamTrack.getSettings()` (Firefox bug 1537986).
#### Removals
* The `DOMMatrix.scaleNonUniformSelf()` method has been removed (Firefox bug 1560119).
### WebDriver conformance (Marionette)
#### Other
* Marionette now dynamically handles the opening and closing of modal dialogs and user prompts (Firefox bug 1477977), which also means that multiple open prompts will be handled (Firefox bug 1487358).
* Tracking protection and DOM push features are now disabled by default to avoid the removal of parts of the DOM, and extra notifications (Firefox bug 1542244).
* Automatic unloading of background tabs if Firefox runs into a low memory condition is now disabled — this badly interacts with automation when switching between tabs (Firefox bug 1553748).
Changes for add-on developers
-----------------------------
### API changes
* The UserScripts API is now enabled by default.
* The `topSites.get()` method now has new options available — `includePinned` and `includeSearchShortcuts` (Firefox bug 1547669).
### Other changes
* There are now Group Policy options to blacklist all extensions except the ones that have been whitelisted (Firefox bug 1522823).
See also
--------
* Hacks release post: Firefox 69 — a tale of Resize Observer, microtasks, CSS, and DevTools
Older versions
--------------
* Firefox 68 for developers
* Firefox 67 for developers
* Firefox 66 for developers
* Firefox 65 for developers
* Firefox 64 for developers
* Firefox 63 for developers
* Firefox 62 for developers
* Firefox 61 for developers
* Firefox 60 for developers
* Firefox 59 for developers
* Firefox 58 for developers
* Firefox 57 for developers
* Firefox 56 for developers
* Firefox 55 for developers
* Firefox 54 for developers
* Firefox 53 for developers
* Firefox 52 for developers
* Firefox 51 for developers
* Firefox 50 for developers
* Firefox 49 for developers
* Firefox 48 for developers
* Firefox 47 for developers
* Firefox 46 for developers
* Firefox 45 for developers
* Firefox 44 for developers
* Firefox 43 for developers
* Firefox 42 for developers
* Firefox 41 for developers
* Firefox 40 for developers
* Firefox 39 for developers
* Firefox 38 for developers |
Firefox 22 for developers - Mozilla | Firefox 22 for developers
=========================
Changes for Web developers
--------------------------
### HTML
* The HTML5 `<data>` element has been implemented (Firefox bug 839371).
* The HTML5 `<time>` element has been implemented (Firefox bug 629801).
* The `range` state of the `<input>` element (`<input type="range">`) has been implemented, behind the preference `dom.experimental_forms_range`, only enabled by default on Nightly and Aurora channel (Firefox bug 841948).
* The support for the `<template>` element, part of the Web component specification has been implemented (Firefox bug 818976).
### JavaScript
* Asm.js optimizations are enabled, making it possible to compile C/C++ applications to a subset of JavaScript for better performance.
* ES2015 Arrow Function syntax has been implemented (Firefox bug 846406).
* The new Object.is function has been added (Firefox bug 839979).
* `arguments` in generator expressions is now inherited from enclosing lexical scope (Firefox bug 848051).
* The ES2015 Proxy `preventExtensions` trap have been implemented (Firefox bug 789897).
### DOM
* Support for the `multipart` property on `XMLHttpRequest` and `multipart/x-mixed-replace` responses in `XMLHttpRequest` has been removed. This was a Gecko-only feature that was never standardized. Server-Sent Events, Web Sockets or inspecting `responseText` from progress events can be used instead.
* Support for Web Notifications has been landed (Firefox bug 782211).
* The `FormData` `append` method now accepts a third optional `filename` parameter (Firefox bug 690659).
* `Node.isSupported` has been removed (Firefox bug 801562).
* `Node.setUserData` and `Node.getUserData` has been removed for web content and are deprecated for chrome content (Firefox bug 842372).
* The `Element.attributes` property has been moved there from `Node` as required by the spec (Firefox bug 844134).
* The Mac OS X backend for **Ambient Light Events** has been implemented.
* Elements in the HTML namespace with local names `<bgsound>`, `<multicol>`, and `<image>` no longer implement the `HTMLSpanElement` interface. `<bgsound>` implements `HTMLUnknownElement` and `<image>` implements `HTMLElement`.
* The `NodeIterator.detach` method has been changed to do nothing (Firefox bug 823549).
* The `BlobEvent` interface has been implemented (Firefox bug 834165).
* The properties `HTMLMediaElement.crossorigin` and `HTMLInputElement.inputmode` has been removed to match the spec in `HTMLMediaElement.crossOrigin` and `HTMLInputElement.inputMode`, respectively (Firefox bug 847370 and Firefox bug 850346).
* WebRTC: the Media Stream API and Peer Connection API are now supported by default.
* Web Components: the `Document.register` method has been implemented (Firefox bug 783129).
* The `ProgressEvent.initProgressEvent()` constructor method has been removed. Use the standard constructor, `ProgressEvent()` to construct and initialize `ProgressEvent` (Firefox bug 843489).
* Manipulated data associated with a `cut`, `copy`, or `paste` event can now be accessed via the `ClipboardEvent.clipboardData` property (Firefox bug 407983).
* The `HTMLTimeElement` interface has been implemented (Firefox bug 629801).
* When a `Worker` constructor is passed an invalid URL, it now throws `DOMException` of type `SECURITY_ERR` (Firefox bug 587251).
### CSS
* Support for CSS Flexbox layout has been enabled by default (Firefox bug 841876).
* Following a spec change, the initial value for `min-width` and `min-height` has been changed back to `0`, even on flex items (Firefox bug 848539).
* Support for CSS Conditionals (`@supports` and `CSS.supports()`) has been enabled by default (Firefox bug 855455).
* Support for `background-clip` and `background-origin` properties in the `background` shorthand has been implemented (Firefox bug 570896).
Changes for add-on and Mozilla developers
-----------------------------------------
* The `properties` parameter has been removed from the `nsITreeView.getCellProperties()`, `nsITreeView.getColumnProperties()` and `nsITreeView.getRowProperties()` methods of `nsITreeView`. These methods should now return a string of space-separated property names (Firefox bug 407956).
* The `inIDOMUtils.getCSSPropertyNames()` method has been implemented and will return all supported CSS property names.
* See here for more changes.
### Firefox Developer Tools
* Font inspector shows which fonts on your computer are applied to the page.
* Visual paint feedback mode shows when and where a page is repainted.
* The dev tools may now be docked to the right side, not just the bottom of the browser.
* Some panes within the dev tools have switched from XUL to HTML. For example, the CSS rule viewer is now chrome://browser/content/devtools/cssruleview.xhtml, not `cssruleview.xul`. Instead of adding an overlay directly to extend features of these panes, you may add an overlay and script to the outer xul document, to add load listeners and change these HTML documents.
* The stack trace is now shown as a breadcrumb near the top, and the script listing is now at the left panel of the debugger.
See also
--------
* Firefox 22 Beta Release Notes
* Add-on Compatibility for Firefox 22
### Versions
* Firefox 21 for developers
* Firefox 20 for developers
* Firefox 19 for developers
* Firefox 18 for developers
* Firefox 17 for developers
* Firefox 16 for developers
* Firefox 15 for developers
* Firefox 14 for developers
* Firefox 13 for developers
* Firefox 12 for developers
* Firefox 11 for developers
* Firefox 10 for developers
* Firefox 9 for developers
* Firefox 8 for developers
* Firefox 7 for developers
* Firefox 6 for developers
* Firefox 5 for developers
* Firefox 4 for developers
* Firefox 3.6 for developers
* Firefox 3.5 for developers
* Firefox 3 for developers
* Firefox 2 for developers
* Firefox 1.5 for developers |
Firefox 123 for developers - Mozilla | Firefox 123 for developers
==========================
This article provides information about the changes in Firefox 123 that affect developers. Firefox 123 is the current Nightly version of Firefox and ships on February 20, 2024.
Changes for web developers
--------------------------
### Developer Tools
### HTML
#### Removals
### CSS
#### Removals
### JavaScript
#### Removals
### SVG
#### Removals
### HTTP
#### Removals
### Security
#### Removals
### APIs
#### DOM
#### Media, WebRTC, and Web Audio
#### Removals
### WebAssembly
#### Removals
### WebDriver conformance (WebDriver BiDi, Marionette)
#### General
#### WebDriver BiDi
#### Marionette
Changes for add-on developers
-----------------------------
* Addition of fhe `contextualIdentities.move` function enables items to be moved in the list of contextual identities. This function enables extensions to customize the order in which contextual identities display in the UI (Firefox bug 1333395).
### Removals
### Other
Experimental web features
-------------------------
These features are newly shipped in Firefox 123 but are disabled by default. To experiment with them, search for the appropriate preference on the `about:config` page and set it to `true`. You can find more such features on the Experimental features page.
Older versions
--------------
* Firefox 122 for developers
* Firefox 121 for developers
* Firefox 120 for developers
* Firefox 119 for developers
* Firefox 118 for developers
* Firefox 117 for developers
* Firefox 116 for developers
* Firefox 115 for developers
* Firefox 114 for developers
* Firefox 113 for developers
* Firefox 112 for developers
* Firefox 111 for developers
* Firefox 110 for developers
* Firefox 109 for developers
* Firefox 108 for developers
* Firefox 107 for developers
* Firefox 106 for developers
* Firefox 105 for developers
* Firefox 104 for developers
* Firefox 103 for developers
* Firefox 102 for developers
* Firefox 101 for developers
* Firefox 100 for developers
* Firefox 99 for developers
* Firefox 98 for developers
* Firefox 97 for developers
* Firefox 96 for developers
* Firefox 95 for developers
* Firefox 94 for developers
* Firefox 93 for developers
* Firefox 92 for developers |
Firefox 80 for developers - Mozilla | Firefox 80 for developers
=========================
This article provides information about the changes in Firefox 80 that will affect developers. Firefox 80 was released on August 25, 2020.
Changes for web developers
--------------------------
### Developer Tools
* You can now block and unblock network requests using the `:block` and `:unblock` helper commands in the Web Console (Firefox bug 1546394).
* When adding a class to an element in the Page Inspector's Rules pane, existing classes are suggested with autocomplete (Refer to Firefox bug 1492797).
* When the Debugger breaks on an exception, the tooltip in the source pane now shows a disclosure triangle that reveals a stack trace (Firefox bug 1643633).
* In the Network Monitor request list, a turtle icon is shown for "slow" requests that exceed a configurable threshold for the waiting time (Firefox bug 1648373).
### HTML
*No changes.*
### CSS
* The standard, unprefixed `appearance` property is now supported; existing `-moz-appearance` and `-webkit-appearance` are now aliases of the unprefixed property (Firefox bug 1620467).
### JavaScript
* The ECMAScript 2021 `export * as namespace` syntax for the `export` statement is now supported (Firefox bug 1496852).
### HTTP
* Previously, when the fullscreen directive was applied to an `<iframe>` (i.e. via the `allow` attribute), it didn't work unless the `allowfullscreen` attribute was also present This has now been fixed (Firefox bug 1608358).
### APIs
#### DOM
* Web Animations API compositing operations are now enabled — see `KeyframeEffect.composite` and `KeyframeEffect.iterationComposite` (Firefox bug 1652676).
#### Removals
* The `outerHeight` and `outerWidth` features of `Window.open()` are no longer exposed to web content (Firefox bug 1623826).
### WebAssembly
* Atomic operations are now allowed on non-shared memories (Firefox bug 1619196).
### WebDriver conformance (Marionette)
* Using `WebDriver:NewWindow` to open a new tab no longer returns too early when running tests in headless mode (Firefox bug 1653281).
* We removed the `name` argument for `WebDriver:SwitchToWindow` — it is not supported for W3C-compatible mode, and shouldn't be used anymore (Firefox bug 1588424).
* We've started to add Fission support for the following commands: `WebDriver:FindElement`, `WebDriver:FindElements`, `WebDriver:GetElementAttribute`, `WebDriver:GetElementProperty`.
* **Known issue**: Opening a new tab by using `WebDriver:NewWindow`, or via an arbitrary script that calls `window.open()`, now automatically switches to that new window (Firefox bug 1661495).
Changes for add-on developers
-----------------------------
*No changes.*
Older versions
--------------
* Firefox 79 for developers
* Firefox 78 for developers
* Firefox 77 for developers
* Firefox 76 for developers
* Firefox 75 for developers
* Firefox 74 for developers
* Firefox 73 for developers
* Firefox 72 for developers
* Firefox 71 for developers
* Firefox 70 for developers
* Firefox 69 for developers
* Firefox 68 for developers
* Firefox 67 for developers
* Firefox 66 for developers
* Firefox 65 for developers
* Firefox 64 for developers
* Firefox 63 for developers
* Firefox 62 for developers
* Firefox 61 for developers
* Firefox 60 for developers
* Firefox 59 for developers
* Firefox 58 for developers
* Firefox 57 for developers
* Firefox 56 for developers
* Firefox 55 for developers
* Firefox 54 for developers
* Firefox 53 for developers
* Firefox 52 for developers
* Firefox 51 for developers
* Firefox 50 for developers
* Firefox 49 for developers |
Firefox 40 for developers - Mozilla | Firefox 40 for developers
=========================
To test the latest developer features of Firefox, install Firefox Developer Edition Firefox 40 was released on August 11, 2015. This article lists key changes that are useful not only for web developers, but also Firefox and Gecko developers as well as add-on developers.
Changes for Web developers
--------------------------
### Developer Tools
Highlights:
* Improvements to the Animations view
* Get help from MDN for CSS property syntax
* Edit filters in the Page Inspector
* Web Console now shows messages from workers
* Filter requests by URL in the Network Monitor
* Many new context menu options in the Network Monitor
* Show when network resources are fetched from the browser cache
* Filter rules in the Page Inspector
More:
* Break at debugger; statements in unnamed eval sources
* Copy URL/Open in New Tab context menu items for Debugger source list pane
* console.dirxml support in the Web Console
* Style Editor: "Open Link In New Tab" item added to stylesheet list
* Inspector selector search now includes class/id results even without css prefix
* Tooltips in box-model view saying which CSS rule caused the value
* Switch between color unit format in the Inspector using Shift+click
* Implement "Scroll Into View" menu item for the Inspector
* Linkify url/id/resource attributes in the Inspector
* IP address tooltip in the Network Monitor
Everything: all devtools bugs fixed between Firefox 39 and Firefox 40.
### CSS
* Prefixed rules (`-moz-`) for `text-decoration-color`, `text-decoration-line`, and `text-decoration-style` have been removed (Firefox bug 1097922).
* The property `text-align` now supports the `match-parent` value (Firefox bug 645642).
* In Quirks Mode, `empty-cells` now defaults to `show`, like in standard mode (Firefox bug 1020400).
* The `-moz-orient` non-standard property, used to style `<meter>` and `<progress>` element has been adapted for vertical writing-modes: the value `auto` has been dropped and the values `inline` and `block` added, with `inline` being the new default value (Firefox bug 1028716).
* The property `font-size-adjust` has been fixed so that `0` is treated as a multiplier (leading to a `0` height for the font, hence hiding it) instead of the `none` value (leading to no adjustment, or a `1.0` value) (Firefox bug 1144885).
* Fix text-overflow doesn't work in vertical writing mode (Firefox bug 1117227).
### HTML
*No change.*
### JavaScript
* Unreachable code after `return` statement (including unreachable expression after semicolon-less return statements) will now show a warning in the console (Firefox bug 1005110, Firefox bug 1151931).
* `Symbol.match` has been added (Firefox bug 1054755).
* Passing an object which has a property named `Symbol.match` with a truthy value to `String.prototype.startsWith`, `String.prototype.endsWith`, and `String.prototype.contains` now throws a `TypeError` (Firefox bug 1054755).
* `RegExp` function returns pattern itself if called without `new` and pattern object has a property named `Symbol.match` with a truthy value, and the pattern object's `constructor` property equals to `RegExp` function. (Firefox bug 1147817).
* Support for the non-standard JS1.7 destructuring for-in has been dropped (Firefox bug 1083498).
* Non-standard initializer expressions in `for...in` loops are now ignored and will present a warning in the console. (Firefox bug 748550 and Firefox bug 1164741).
* `\u{xxxxxx}` Unicode code point escapes have been added (Firefox bug 320500).
* `String.prototype.contains` has been replaced with `String.prototype.includes`, `String.prototype.contains` is kept as an alias (Firefox bug 1102219).
* If the `DataView` constructor is called as a function without the `new` operator, a `TypeError` is now thrown as per the ES2015 specification.
* An issue regressed in Firefox 21, where proxyfied arrays without the `get` trap were not working properly, has been fixed. If the `get` trap in a `Proxy` was not defined, `Array.length` returned `0` and the `set` trap didn't get called. A workaround was to add the `get` trap even if was not necessary in your code. This issue has been fixed now (Firefox bug 895223).
* `WeakMap.prototype` and `WeakSet.prototype` have been updated to be just ordinary objects, per ES2015 specification (Firefox bug 1055473).
### Interfaces/APIs/DOM
#### New APIs
* The Push API has been experimentally implemented (Firefox bug 1038811). Controlled by the `services.push.enabled` pref, it is disabled by default.
#### Web Animations API
Improvement in our experimental Web Animations implementation, mostly to match latest spec changes:
* `AnimationPlayer.currentTime` now can also be set (Firefox bug 1072037).
* `Animatable.getAnimationPlayers()`, available on `Element` has been renamed to `Element.getAnimations()` (Firefox bug 1145246).
* `Animation` and `AnimationEffect` have been merged into the newly created `KeyframeEffectReadOnly` (Firefox bug 1153734).
* `AnimationPlayer` has been renamed to `Animation` (Firefox bug 1154615).
* `AnimationTimeline` is now an abstract class, with `DocumentTimeline` its only implementation (Firefox bug 1152171).
#### CSSOM
* The CSS Font Loading API is now enabled by default in Nightly and Developer Edition releases (Firefox bug 1088437). It is still deactivated by default in Beta and Release browsers.
* The `CSSCharsetRule` interface has been removed and such objects are no longer available in CSSOM (Firefox bug 1148694). This matches the spec (recently adapted) and Chrome behavior.
#### WebRTC
* WebRTC: the `negotiationneeded` event is now also sent for initial negotiations, not only for re-negotiations (Firefox bug 1149838).
#### DOM & HTML DOM
* When unable to parse the `srcset`, the `HTMLImageElement.currentSrc` method doesn't return `null` anymore but `""`, as requested by the latest specification (Firefox bug 1139560).
* Like for images, Firefox now throttles `Window.requestAnimationFrame()` for non-visible `<iframe>` (Firefox bug 1145439).
* `Navigator.taintEnabled` is no longer available for Web workers (Firefox bug 1154878).
#### Web Audio API
New extensions to the Web Audio API:
* The `AudioContext.state` and `AudioContext.onstatechange` properties as well as the methods `AudioContext.suspend()`, `AudioContext.resume()`, and `AudioContext.close()` have been added (Firefox bug 1094764).
* `AudioBufferSourceNode` now implements the `AudioBufferSourceNode.detune` k-rate attribute (Firefox bug 1153783).
#### Web Workers
* Slight improvement in our Service Worker API: the `update()` method has been moved from `ServiceWorkerGlobalScope` to `ServiceWorkerRegistration` (Firefox bug 1131350).
* `ServiceWorkerRegistration` is now available in Web workers (Firefox bug 1131327).
* `DataStore` is now available in Web workers (Firefox bug 916196).
#### IndexedDB
* `IDBTransaction` are now non-durable by default (Firefox bug 1112702). This favors performance over reliability and matches what other browsers are doing. For more information, read our durability definition.
#### Dev Tools
* The property `console.timeStamp()` has been added (Firefox bug 922221).
### MathML
*No change.*
### SVG
*No change.*
### Audio/Video
*No change.*
Networking
----------
*No change.*
Security
--------
* Using an asterisk (`*`) in a CSP does not include the schemes `data:`, `blob:` or `:filesystem` anymore when matching source expressions. So those schemes now need to be explicitly defined within the related header to match the CSP (Firefox bug 1086999).
Changes for add-on and Mozilla developers
-----------------------------------------
### XUL
* It is no longer possible to create transparent top-level windows Firefox bug 1162649.
### JavaScript code modules
* Dict.jsm has been removed Firefox bug 1123309. Use `Map` instead.
### XPCOM
* The `nsIClassInfo.implementationLanguage` attribute has been removed, along with the `nsClassInfo::GetImplementationLanguage()` function.
* The following XPCOM interfaces have been removed; you should use the standard HTML interfaces instead:
+ `nsIDOMHTMLBRElement`
+ `nsIDOMDivElement`
+ `nsIDOMHTMLHeadingElement`
+ `nsIDOMHTMLTableCaptionElement`
+ `nsIDOMHTMLTableElement`
+ `nsIDOMHTMLTitleElement`
### Other
* Places Keywords API has been deprecated and will be removed soon (Firefox bug 1140395).
* The automated testing system now supports skipping individual test functions. See running conditional tests in XPCShell testing.
Older versions
--------------
* Firefox 39 for developers
* Firefox 38 for developers
* Firefox 37 for developers
* Firefox 36 for developers
* Firefox 35 for developers
* Firefox 34 for developers
* Firefox 33 for developers
* Firefox 32 for developers
* Firefox 31 for developers
* Firefox 30 for developers
* Firefox 29 for developers
* Firefox 28 for developers
* Firefox 27 for developers
* Firefox 26 for developers
* Firefox 25 for developers
* Firefox 24 for developers
* Firefox 23 for developers
* Firefox 22 for developers
* Firefox 21 for developers
* Firefox 20 for developers
* Firefox 19 for developers
* Firefox 18 for developers
* Firefox 17 for developers
* Firefox 16 for developers
* Firefox 15 for developers
* Firefox 14 for developers
* Firefox 13 for developers
* Firefox 12 for developers
* Firefox 11 for developers
* Firefox 10 for developers
* Firefox 9 for developers |
Firefox 98 for developers - Mozilla | Firefox 98 for developers
=========================
This article provides information about the changes in Firefox 98 that affect developers. Firefox 98 was released on March 8, 2022.
Changes for web developers
--------------------------
### HTML
* The HTML `<dialog>` element is now available by default. This element and its associated DOM APIs provide support for HTML-based modal dialog boxes (Firefox bug 1733536).
### CSS
* The `hyphenate-character` property sets a string that is used instead of a hyphen character (`-`) at the end of a hyphenation line break (Firefox bug 1751024).
### JavaScript
No notable changes
### APIs
* `navigator.registerProtocolHandler()` can now register protocol handlers for the `ftp`, `sftp`, and `ftps` schemes (Firefox bug 1705202).
#### DOM
* `HTMLElement.outerText` is now supported (Firefox bug 1709790).
* The properties `colorSpaceConversion`, `resizeWidth` and `resizeHeight` can be passed to the method `createImageBitmap()` using the `options` object (Firefox bug 1748868 and Firefox bug 1733559).
#### Removals
* The deprecated WebVR API is now disabled by default on all builds (previously it was enabled on Windows, macOS, and all nightly/dev builds).
It can be re-enabled in `about:config` by setting `dom.vr.enabled` to `true` (Firefox bug 1750902).
### WebDriver conformance (Marionette)
* Improved initial page load checks for newly opened tabs (Firefox bug 1747359).
Changes for add-on developers
-----------------------------
* Web extensions using `webRequest` were started early during Firefox startup. This has changed to only trigger early start-up for extensions using `webRequest` blocking calls. Non-blocking calls no longer cause the early startup of an extension. (Firefox bug 1749871)
* `cookieStoreId` added to `userScripts.register`. This enables extensions to register container-specific user scripts (Firefox bug 1738567).
Older versions
--------------
* Firefox 97 for developers
* Firefox 96 for developers
* Firefox 95 for developers
* Firefox 94 for developers
* Firefox 93 for developers
* Firefox 92 for developers
* Firefox 91 for developers
* Firefox 90 for developers
* Firefox 89 for developers
* Firefox 88 for developers
* Firefox 87 for developers
* Firefox 86 for developers
* Firefox 85 for developers
* Firefox 84 for developers
* Firefox 83 for developers
* Firefox 82 for developers
* Firefox 81 for developers
* Firefox 80 for developers
* Firefox 79 for developers
* Firefox 78 for developers
* Firefox 77 for developers
* Firefox 76 for developers
* Firefox 75 for developers
* Firefox 74 for developers
* Firefox 73 for developers
* Firefox 72 for developers
* Firefox 71 for developers
* Firefox 70 for developers
* Firefox 69 for developers
* Firefox 68 for developers
* Firefox 67 for developers |
Firefox 71 for Developers - Mozilla | Firefox 71 for Developers
=========================
This article provides information about the changes in Firefox 71 that will affect developers. Firefox 71 was released on December 3, 2019.
Changes for web developers
--------------------------
### Developer tools
Console:
* The Console's multi-line mode is now available by default.
* Console configuration options are now combined in a new toolbar settings menu (Firefox bug 1523868).
JavaScript debugger:
* Inline variable preview has been enabled (Firefox bug 1576679).
* Logging on events is now available (Firefox bug 1110276), as is the ability to filter by event type.
* The new debugger paused overlay can now be disabled using the `devtools.debugger.features.overlay` pref (Firefox bug 1579768).
* We've got new keyboard shortcuts for opening the debugger: `Ctrl` + `Shift` + `Z` on Linux/Windows and `Cmd` + `Opt` + `Z` on macOS (Firefox bug 1583042).
* Pausing on a DOM Mutation Breakpoints now mentions the DOM node that has the breakpoint and, if available, the child node that was added/removed (Firefox bug 1576145).
* Locations in pretty printed sources are now correct after pretty-printing and when jumping to the source from the Inspector's events listener tooltip (Firefox bug 1500222).
Network Monitor:
* The Web sockets inspector is now enabled by default (Firefox bug 1573805).
* You can now do a full-text search of request/response bodies, headers, and cookies.
* You can now enter patterns to block specific URLs from loading.
* The Timings tab now exposes timing data sent in the `Server-Timing` header (Firefox bug 1403051).
Page Inspector:
* Color swatches are now shown next to CSS variable definitions that have color values (Firefox bug 1456167).
* `:visited` styles are now shown in the CSS rules view (Firefox bug 713106).
### CSS
* Added the subgrid value from CSS Grid Level 2 to `grid-template-columns` and `grid-template-rows` (Firefox bug 1580894)
* Added support for the `column-span` property to Multiple-column Layout (Firefox bug 1426010)
* Added support for the `path()` value of `clip-path` (Firefox bug 1488530)
* Mapped the `height` and `width` HTML attributes on the `<img>` element to an internal `aspect-ratio` property (Firefox bug 1585637). See the guide to this feature on MDN.
#### Removals
* CSS Radial Gradients no longer accept negative radii (Firefox bug 1583736).
### JavaScript
* The `Promise.allSettled()` method is now supported (Firefox bug 1549176). This method lets you easily wait until every promise in a set of promises is either fulfilled or rejected before running further code.
#### Removals
* The non-standard Array generic methods have been removed in Firefox 71 (Firefox bug 1222547). They were first introduced in Firefox 1.5 and deprecated from Firefox 68 onwards. If your use case is to use array generics on array-like objects, you can convert your object to a proper array using `Array.from()` and then use standard array methods.
### MathML
* MathML elements now implement a MathML DOM and their class is `MathMLElement`. With a proper MathML DOM, you can now use `mathmlEl.style`, or global event handlers, for example. Prior to this change, MathML elements only implemented the `Element` class (Firefox bug 1571487).
### APIs
#### New APIs
The Media Session API is now partially implemented. This API provides a standard mechanism for your content to share with the underlying operating system information about the state of media it's playing. This includes metadata such as artist, album, and track name, as well as potentially album artwork (Firefox bug 1580602).
The API also provides a way to receive notifications when the device's media controls (such as play, pause, and seek buttons) are activated by the user. To that end, the `MediaSession` interface is now partially implemented, with support for setting and fetching the currently-playing media's metadata and for the `setActionHandler()` method. To access the `MediaSession` API, use the `navigator.mediaSession` property.
#### DOM
* The `StaticRange()` constructor is now supported (Firefox bug 1575980).
* The MathML `MathMLElement` interface has been implemented (Firefox bug 1571487).
#### Media, Web Audio, and WebRTC
* The `MediaRecorder` interface now implements the `audioBitsPerSecond` and `videoBitsPerSecond` properties (Firefox bug 1514158).
#### Canvas and WebGL
* The `OVR_multiview2` and `OES_fbo_render_mipmap` WebGL extensions are now exposed by default (Firefox bug 1584277, Firefox bug 1583878).
#### Removals
The following non-standard `DataTransfer` members have been removed (Firefox bug 1345192):
* `DataTransfer.mozItemCount`
* `DataTransfer.mozClearDataAt()`
* `DataTransfer.mozGetDataAt()`
* `DataTransfer.mozSetDataAt()`
* `DataTransfer.mozTypesAt()`
### WebDriver conformance (Marionette)
* Both the `WebDriver:TakeScreenshot` and `WebDriver:TakeElementScreenshot` commands have been updated to respect the unhandled prompt behavior setting (Firefox bug 1584927).
* The command `Marionette:Quit` has been updated to also allow quitting or restarting of other Gecko-driven applications besides Firefox (Firefox bug 1298921).
* For GeckoView-based browsers on Android, the returned `browserName` in the session capabilities will now always be `firefox` (Firefox bug 1587364).
Changes for add-on developers
-----------------------------
### API changes
* `downloads.download` now identifies and reports as errors the following HTTP response codes:
+ 404 returning `SERVER_BAD_CONTENT`
+ 403 returning `SERVER_FORBIDDEN`
+ 402 and Proxy 407 returning `SERVER_UNAUTHORIZED`
+ Anything else above 400 returning `SERVER_FAILED` (Firefox bug 1576333)
* `downloads.download` now includes the optional `options` parameter property `allowHttpErrors`. When set to `true`, this `boolean` flag enables a download to continue after encountering an HTTP error. When set to `false`, a download is canceled when an HTTP error is encountered. Default value: `false`. (Firefox bug 1578955)
#### Removals
* The `proxy.register()` and `proxy.unregister()` functions have been removed (Firefox bug 1443259). `proxy.onRequest` should now be used to handle the proxying of requests.
See also
--------
* Hacks release post: Firefox 71: A year-end arrival
Older versions
--------------
* Firefox 70 for developers
* Firefox 69 for developers
* Firefox 68 for developers
* Firefox 67 for developers
* Firefox 66 for developers
* Firefox 65 for developers
* Firefox 64 for developers
* Firefox 63 for developers
* Firefox 62 for developers
* Firefox 61 for developers
* Firefox 60 for developers
* Firefox 59 for developers
* Firefox 58 for developers
* Firefox 57 for developers
* Firefox 56 for developers
* Firefox 55 for developers
* Firefox 54 for developers
* Firefox 53 for developers
* Firefox 52 for developers
* Firefox 51 for developers
* Firefox 50 for developers
* Firefox 49 for developers
* Firefox 48 for developers
* Firefox 47 for developers
* Firefox 46 for developers
* Firefox 45 for developers
* Firefox 44 for developers
* Firefox 43 for developers
* Firefox 42 for developers
* Firefox 41 for developers
* Firefox 40 for developers |
Firefox 94 for developers - Mozilla | Firefox 94 for developers
=========================
This article provides information about the changes in Firefox 94 that will affect developers. Firefox 94 was released on November 2nd, 2021
Changes for web developers
--------------------------
### HTML
No notable changes
### CSS
No notable changes
### JavaScript
No notable changes
### APIs
* The `structuredClone()` global function is now supported for copying complex JavaScript objects (Firefox bug 1722576).
#### DOM
* Developers can now provide a hint for the enter key label/icon used on virtual keyboards, using either `HTMLElement.enterkeyhint` or the global attribute `enterkeyhint` (Firefox bug 1648332).
* The `HTMLScriptElement.supports()` static method is now supported. This provides a simple and unified method for feature checking whether a browser supports particular types of scripts, such as JavaScript modules or classic scripts (Firefox bug 1729239).
* The `ShadowRoot.delegatesFocus` property is now supported, allowing code to check whether the `delegatesFocus` property was set when the shadow DOM was attached (Firefox bug 1413836).
### WebDriver conformance (Marionette)
* `WebDriver:GetWindowHandle` and `WebDriver:GetWindowHandles` now return handles for browser windows instead of tabs, when chrome scope is enabled (Firefox bug 1729291)
### HTTP
* The `cache` directive of the `Clear-Site-Data` response header has been disabled by default.
It can be enabled using the preference `privacy.clearsitedata.cache.enabled` (Firefox bug 1729291).
Changes for add-on developers
-----------------------------
* Support for `partitionKey`, the first-party URL of a cookie when it's in storage that is partitioned by top-level site, is added to `cookies.get`, `cookies.getAll`, `cookies.set`, `cookies.remove`, and `cookies.cookie`. (Firefox bug 1669716)
* When a context menu is activated, `menus.OnClickData.srcUrl` returns the raw value of the `src` attribute of the clicked element, instead of the current URL (after redirects). (Firefox bug 1659155)
Older versions
--------------
* Firefox 93 for developers
* Firefox 92 for developers
* Firefox 91 for developers
* Firefox 90 for developers
* Firefox 89 for developers
* Firefox 88 for developers
* Firefox 87 for developers
* Firefox 86 for developers
* Firefox 85 for developers
* Firefox 84 for developers
* Firefox 83 for developers
* Firefox 82 for developers
* Firefox 81 for developers
* Firefox 80 for developers
* Firefox 79 for developers
* Firefox 78 for developers
* Firefox 77 for developers
* Firefox 76 for developers
* Firefox 75 for developers
* Firefox 74 for developers
* Firefox 73 for developers
* Firefox 72 for developers
* Firefox 71 for developers
* Firefox 70 for developers
* Firefox 69 for developers
* Firefox 68 for developers
* Firefox 67 for developers
* Firefox 66 for developers
* Firefox 65 for developers
* Firefox 64 for developers
* Firefox 63 for developers |
Firefox 36 for developers - Mozilla | Firefox 36 for developers
=========================
Firefox 36 was released on February 24th, 2015. This article lists key changes that are useful not only for web developers, but also Firefox and Gecko developers as well as add-on developers.
Changes for Web developers
--------------------------
### Developer Tools
Highlights:
* eval sources now appear in the Debugger
* Simpler process for connecting to Firefox for Android
* Box Model Highlighter works on remote targets
* "Invert the call tree" option in the Profiler
* Inspect DOM promises in the console
* Extra "Paste" commands in the Inspector
All devtools bugs fixed between Firefox 35 and Firefox 36.
### CSS
* The `will-change` property has been enabled by default (Firefox bug 961871).
* The `white-space` property is now working on `<textarea>` HTML elements (Firefox bug 82711).
* The `unicode-range` descriptor is now supported by `@font-face` (Firefox bug 475891), but not enabled by default.
* The properties `text-decoration-color`, `text-decoration-line`, and `text-decoration-style` are unprefixed (Firefox bug 825004). The prefixed version are still available for some time to ease transition (Firefox bug 1097922).
* The `text-decoration` property is turned into shorthand property (Firefox bug 1039488).
* The properties `object-fit` and `object-position` are now supported (Firefox bug 624647)
* The `contents` value of the `display` property has been experimentally implemented. It is preffed off by default (Firefox bug 907396).
* In Quirks mode, the `:active` and `:hover` quiver quirk has been altered to be applied less often: it is now used only on links, only if there are no pseudo-element or other pseudo-class in the element and if it isn't part of a pseudo-class element (Firefox bug 783213).
* The `isolation` property has been implemented (Firefox bug 1077872).
* CSS `<gradient>` now applies on the premultiplied colors, matching the spec and other browsers, and getting rid of unexpected gray colors appearing in them (Firefox bug 591600).
* Interpolation hint syntax has been added to `<gradient>` (Firefox bug 1074056).
* The `scroll-behavior` property has been implemented (Firefox bug 1010538).
### HTML
* Support for `<meta name="referrer">` has been added (Firefox bug 704320).
* In Firefox, `<input>` filters specified in the `accept` attribute will always be selected by default, unless there is an unknown value, that is an unknown mime type or badly formatted value in the `accept` attribute. Previously specified filters were only selected by default for `image/*`, `video/*` and `audio/*` values (Firefox bug 826185).
### JavaScript
* The ECMAScript 2015 Symbol data type has been enabled by default (was available in the Nightly channel since version 33) (Firefox bug 1066322):
+ `Symbol`
+ `Symbol.for()`
+ `Symbol.keyFor()`
+ `Object.getOwnPropertySymbols()`
* The old placeholder string `"@@iterator"` has been replaced with the real ES2015 well-known symbol `Symbol.iterator` for the iterable interface property key (Firefox bug 918828).
* The spec-internal abstract operation `ToNumber(string)` now supports binary (`0b`) and octal (`0o`) literals, this is a potentially breaking change from ES5 (Firefox bug 1079120).
+ `Number("0b11")` now returns `3`, not `NaN`.
+ `"0o11" == 9` now returns `true`, not `false`.
* The `const` declaration is now block-scoped and requires an initializer (Firefox bug 611388). It also can not be redeclared anymore (Firefox bug 1095439).
+ `{const a=1}; a;` now throws a `ReferenceError` and does not return `1` anymore due to block-scoping.
+ `const a;` now throws a `SyntaxError` ("missing = in const declaration`"`): An initializer is required.
+ `const a = 1; a = 2;` now also throws a `SyntaxError` ("invalid assignment to const a").
* The ES2016 method `Array.prototype.includes` has been implemented, but for now, it is only enabled in Nightly builds (Firefox bug 1069063).
* The `delete` operator now triggers the "temporal dead zone" when using with `let` and `const` (Firefox bug 1074571).
* The non-standard `let` blocks and `let` expressions are deprecated and will now log a warning in the console. Do not use them anymore, they will be removed in the future.
* WeakMap constructor now handles optional iterable argument (Firefox bug 1092537).
### Interfaces/APIs/DOM
* The `CanvasRenderingContext2D.resetTransform()` method of the Canvas API has been implemented (Firefox bug 1099148).
* ECDSA is now supported in the Web Crypto API (Firefox bug 1034854).
* Our experimental implementation of WebGL 2.0 is going forward!
+ The `WebGLQuery` interface is available (Firefox bug 1048719).
+ The `WebGL2RenderingContext.invalidateFrameBuffer()` method has been implemented (Firefox bug 1076456).
* The `MediaDevices` interface, containing the `Promise`-based version of `getUserMedia()`, has been added. It is available via `Navigator.mediaDevices` (Firefox bug 1033885).
* The EME-related `Navigator.requestMediaKeySystemAccess()` method, and the related `MediaKeySystemAccess`, is now supported (Firefox bug 1095257).
* The `keyschange` event is now sent when an EME-related CDM change keys in a session (Firefox bug 1081755).
* The default values of the options for `MutationObserver.observe()` have been updated to match the latest specification (Firefox bug 973638).
* Experimental support for virtual reality devices has landed behind the `dom.vr.enabled` preference, off by default (Firefox bug 1036604).
* The function associated with `RTCPeerConnection.onsignalingstatechange` now receives an event as parameter, as per spec (Firefox bug 1075133).
* The experimental implementation of Web Animations make progress: the method `AnimationPlayer.play()` and `AnimationPlayer.pause()` are now supported (Firefox bug 1070745), as well as `AnimationPlayer.playState` (Firefox bug 1037321).
* The non-standard `DOMRequest` interface has now a `DOMRequest.then()` method (Firefox bug 839838).
* The CSSOM View scroll behavior controlling methods, `Element.scroll()`, `Element.scrollTo()`, `Element.scrollBy()`, and `Element.scrollIntoView()`, have been implemented or extended (Firefox bug 1045754 and Firefox bug 1087559).
* Assigning to `Element.innerHTML` on an `SVGElement` now create elements in the SVG namespace (Firefox bug 886390).
* The `nsIWebBrowserPersist.saveURI()` method now requires 8 arguments, in an order incompatible with previous releases.
* Support for Media Source Extensions (MSE) is activated by default in non-build releases (Nightly and Developer Edition only) (Firefox bug 1000686). It keeps being preffed off on Beta and Release version.
### MathML
*No change.*
### SVG
*No change.*
### Audio/Video
*No change.*
Networking
----------
* Support for SPDY/3 has been removed; support for SPDY/3.1 is still available (Firefox bug 1097944).
Security
--------
* RC4 is now considered as insecure and all UI indicators will react as such; SSLv3 has been disabled by default in Firefox 34, but the UI has been changed to help the user better understand what is happening (Firefox bug 1093595).
* Also, RC4 is no longer offered in the initial handshake of TLS (Firefox bug 1088915).
* The `form-action` directive of CSP 1.1 is now supported (Firefox bug 529697).
* In the preferences of Firefox, The Do not track selection widget is again an on/off switch (Firefox bug 1071747).
Changes for add-on and Mozilla developers
-----------------------------------------
### Add-on SDK
#### Highlights
* The `sdk/test/httpd` module was removed, use the addon-httpd npm module instead.
* Add badges to `sdk/ui` buttons (Firefox bug 994280).
* Implemented global `require` function to access sdk modules anywhere (Firefox bug 1070927), using:
```js
var { require } = Cu.import(
"resource://gre/modules/commonjs/toolkit/require.js",
{},
);
```
#### Details
GitHub commits made between Firefox 35 and Firefox 36.
### JavaScript code modules
* `PromiseUtils.resolveOrTimeout` is implemented (Firefox bug 1080466).
* `PromiseUtils.defer` (a replacement for `Promise.defer()`) is implemented (Firefox bug 1093021).
### Interfaces
#### nsIContentPolicy
New constants have been added to `nsIContentPolicy` to allow Gecko internals and add-on code to better differentiate different types of requests. These are:
`TYPE_FETCH`
Indicates a content load request initiated by the `fetch()` method.
`TYPE_IMAGESET`
Indicates a request to load an `<img>` (with the `srcset` attribute or `<picture>` element.
### XUL
*No change.*
### Other
* Firefox `-remote` command line option has been removed (Firefox bug 1080319).
Older versions
--------------
* Firefox 35 for developers
* Firefox 34 for developers
* Firefox 33 for developers
* Firefox 32 for developers
* Firefox 31 for developers
* Firefox 30 for developers
* Firefox 29 for developers
* Firefox 28 for developers
* Firefox 27 for developers
* Firefox 26 for developers
* Firefox 25 for developers
* Firefox 24 for developers
* Firefox 23 for developers
* Firefox 22 for developers
* Firefox 21 for developers
* Firefox 20 for developers
* Firefox 19 for developers
* Firefox 18 for developers
* Firefox 17 for developers
* Firefox 16 for developers
* Firefox 15 for developers
* Firefox 14 for developers
* Firefox 13 for developers
* Firefox 12 for developers
* Firefox 11 for developers
* Firefox 10 for developers
* Firefox 9 for developers
* Firefox 8 for developers
* Firefox 7 for developers
* Firefox 6 for developers
* Firefox 5 for developers |
Firefox 106 for developers - Mozilla | Firefox 106 for developers
==========================
This article provides information about the changes in Firefox 106 that will affect developers. Firefox 106 was released on October 18, 2022.
Changes for web developers
--------------------------
### HTML
* The `<source>` element now supports `height` & `width` attributes when it is a child of a `<picture>` element.
This functionality is an experimental feature enabled using the `dom.picture_source_dimension_attributes.enabled` preference (Firefox bug 1694741).
### MathML
* The `<semantics>` and `<maction>` MathML elements now only render the first child element by default (Firefox bug 1588733).
### CSS
* The @supports at-rule now supports the `font-tech()` and `font-format()` functions.
These functions can be used to test whether a browser supports a given font technology or format and CSS styles can be applied based on the result (Firefox bug 1786493).
### JavaScript
No notable changes.
### HTTP
No notable changes.
### Security
No notable changes.
### APIs
#### DOM
* The `HTMLMetaElement.media` property is now supported. This property enables you to set different theme colors based on `media` values (e.g. `max-width: 600px`).
Meta elements with `media` properties allow the browser to use the `content` value in conjunction with `theme-color` to set the page or UI colors for a given media query (Firefox bug 1706179).
### WebAssembly
No notable changes.
### WebDriver conformance (WebDriver BiDi, Marionette)
#### WebDriver BiDi
* Added basic support for the `script.getRealms` command that is currently limited to the `WindowRealmInfo` type which includes window realms and sandbox realms (Firefox bug 1766240).
* Added support for the `browsingContext.load` event, which is emitted when a `load` event is triggered on a BrowsingContext's window (Firefox bug 1756619).
* Added an object reference store to hold strong references for serialized remote values (Firefox bug 1770736).
* Added support for de-serializing remote references created in the object reference store (Firefox bug 1788124).
* Added full support for the `script.evaluate`, `script.callFunction` and `script.disown` commands (Firefox bug 1778976).
#### Marionette
* Added support for `wheel` input source for Actions, which is associated with a wheel-type input device (Firefox bug 1746601).
* Added support for opening and closing tabs in GeckoView based applications (eg. Firefox for Android) (Firefox bug 1506782).
Changes for add-on developers
-----------------------------
* The ability to set the `"background"` manifest key property `"persistent"` to `false` for Manifest V2 (to make a background page non-persistent) is now available by default.
* The `object-src` directive in the `"content_security_policy"` manifest key is now optional (Firefox bug 1766881). See object-src directive on the `"content_security_policy"` manifest key page for more details.
Older versions
--------------
* Firefox 105 for developers
* Firefox 104 for developers
* Firefox 103 for developers
* Firefox 102 for developers
* Firefox 101 for developers
* Firefox 100 for developers
* Firefox 99 for developers
* Firefox 98 for developers
* Firefox 97 for developers
* Firefox 96 for developers
* Firefox 95 for developers
* Firefox 94 for developers
* Firefox 93 for developers
* Firefox 92 for developers
* Firefox 91 for developers
* Firefox 90 for developers
* Firefox 89 for developers
* Firefox 88 for developers
* Firefox 87 for developers
* Firefox 86 for developers
* Firefox 85 for developers
* Firefox 84 for developers
* Firefox 83 for developers
* Firefox 82 for developers
* Firefox 81 for developers
* Firefox 80 for developers
* Firefox 79 for developers
* Firefox 78 for developers
* Firefox 77 for developers
* Firefox 76 for developers
* Firefox 75 for developers |
Firefox 65 for developers - Mozilla | Firefox 65 for developers
=========================
This article provides information about the changes in Firefox 65 that will affect developers. Firefox 65 was released on January 29, 2019.
Changes for web developers
--------------------------
### Developer tools
* The Flexbox inspector is now enabled by default.
* Support has been added to the JavaScript Debugger for XHR Breakpoints (Firefox bug 821610).
* Right-click on an item in the accessibility tree from the Accessibility viewer to print it as JSON to the JSON viewer.
* The color contrast display of the Accessibility Picker has been updated so that if a text's background is complex (e.g. a gradient or complex image), it shows a range of color contrast values.
* The Headers tab of the Network Monitor now displays the Referrer Policy for the selected request (Firefox bug 1496742).
* When displaying stack traces (e.g. in console logs or the JavaScript debugger), calls to framework methods are identified and collapsed by default, making it easier to home in on your code.
* In the same fashion as native terminals, you can now use reverse search to find entries in your JavaScript console history (`F9` on Windows/Linux or `Ctrl` + `R` on macOS, then type a search term, followed by `Ctrl` + `R`/`Ctrl` + `S` to toggle through results).
* The JavaScript console's `$0` shortcut (references the currently inspected element on the page) now has autocomplete available, so for example you could type `$0.te` to get autocomplete suggestions for properties like `$0.textContent`.
* The edits you make in the Rules view of the Inspector are now listed in the Changes panel (Firefox bug 1503920).
### HTML
* Events are now dispatched on disabled HTML elements, i.e. `<button>`, `<fieldset>`, `<input>`, `<select>`, and `<textarea>` elements with `disabled` attributes set on them (Firefox bug 329509).
* Removing the `src` attribute of an `<iframe>` element now causes `about:blank` to be loaded into it, giving it parity with Chrome and Safari (Firefox bug 1507842). Previously removing `src` had no effect on the `iframe` content.
* We have added support for the `referrerpolicy` attribute on `<script>` elements (Firefox bug 1460920).
### CSS
* The `image-rendering` property's `crisp-edges` value has now been unprefixed (Firefox bug 1496617).
* A `scrollbar-color` value of `auto` now resolves to `auto`, rather than two colors (Firefox bug 1501418).
* The `break-*` properties have been implemented, and the legacy `page-break-*` properties have been aliased to them (Firefox bug 775618):
+ `break-before` is now an alias for `page-break-before`.
+ `break-after` is now an alias for `page-break-after`.
+ `break-inside` is now an alias for `page-break-inside`.
* The `overflow-wrap` property's `anywhere` value has been implemented (Firefox bug 1505786).
* The new step position keywords `jump-start`, `jump-end`, `jump-none`, and `jump-both` — usable inside the `steps()` timing function — have been implemented (Firefox bug 1496619). This also coincides with the removal of the `frames()` timing function, which was the previous way of implementing such functionality, now deprecated.
* Some new `-webkit-appearance` values have been added, for compatibility with other browsers. In particular:
+ `meter`, which is now used as the default value for `<meter>` elements in UA stylesheets. The existing value `meterbar` is now an alias for `meter` (Firefox bug 1501483).
+ `progress-bar`, which is now used as the default value for `<progress>` elements in UA stylesheets. The existing value `progressbar` is now an alias for `progress-bar` (Firefox bug 1501506).
+ `textarea`, which is now used as the default value for `<textarea>` elements in UA stylesheets. The existing value `textfield-multiline` is now an alias for `textarea` (Firefox bug 1507905).
* The behavior of `user-select` has been changed to make it align more with other browsers (Firefox bug 1506547). Specifically:
+ `user-select: all` set on an element no longer overrides other values of `user-select` set on children of that element. So for example in the following snippet:
html
```html
<div style="-webkit-user-select: all">
All
<div style="-webkit-user-select: none">None</div>
</div>
```
The `<div>` with `none` set on it is now non-selectable. Previously this value would have been overridden by the `all` value set on the parent element.
+ non-`contenteditable` elements nested inside `contenteditable` elements are now selectable.
+ `user-select` now behaves consistently inside and outside shadow DOM.
+ The proprietary `-moz-text` value has been removed.
* CSS environment variables (the `env()` function) have been implemented (Firefox bug 1462233).
#### Removals
* The `layout.css.shape-outside.enabled` pref has been removed; `shape-outside`, `shape-margin`, and `shape-image-threshold` can no longer be disabled in `about:config` (Firefox bug 1504387).
* Several Firefox-only values of the `user-select` property have been removed — `-moz-all`, `-moz-text`, `tri-state`, `element`, `elements`, and `toggle`. See Firefox bug 1492958 and Firefox bug 1506547.
* As mentioned above, the `frames()` timing function has been removed (Firefox bug 1496619).
### SVG
*No changes.*
### JavaScript
* `Intl.RelativeTimeFormat` is now supported (Firefox bug 1504334).
* Strings now have a maximum length of `2**30 - 2` (~1GB) instead of `2**28 - 1` (~256MB) (Firefox bug 1509542).
* The `globalThis` property, which always refers to the top-level global object, has been implemented (Firefox bug 1317422).
### APIs
#### New APIs
* Readable Streams have been enabled by default (Firefox bug 1505122).
* The Storage Access API has been enabled by default (Firefox bug 1513021).
#### DOM
* `Performance.toJSON()` has been exposed to Web Workers (Firefox bug 1504958).
* `XMLHttpRequest` requests will now throw a `NetworkError` if the requested content type is a `Blob`, and the request method is not `GET` (Firefox bug 1502599).
* The `-moz-` prefixed versions of many of the Fullscreen API features have been deprecated, and will now display deprecation warnings in the JavaScript console when encountered (Firefox bug 1504946).
* `createImageBitmap()` now supports SVG images (`SVGImageElement`) as an image source (Firefox bug 1500768).
#### DOM events
* Going forward, only one `Window.open()` call is allowed per event (Firefox bug 675574).
* The `keyup` and `keydown` events are now fired during IME composition, to improve cross-browser compatibility for CJKT users (Firefox bug 354358.
#### Web workers
* `SharedWorkerGlobalScope.connect`'s event object is a `MessageEvent` instance — its `data` property is now an empty string value rather than `null` (Firefox bug 1508824).
#### Fetch and Service workers
* The `Response.redirect()` method now correctly throws a `TypeError` if a non-valid URL is specified as the first parameter (Firefox bug 1503276).
* The `ServiceWorkerContainer.register()` and `WorkerGlobalScope.importScripts()` (when used by a service worker) methods will now accept any files with a valid JavaScript MIME type (Firefox bug 1354577).
* The `FetchEvent.replacesClientId` and `FetchEvent.resultingClientId` properties are now supported (Firefox bug 1264177).
* The `ServiceWorkerGlobalScope.onmessageerror` and `ServiceWorkerContainer.onmessageerror` handler properties have been implemented (Firefox bug 1399446).
* The `Origin` header is no longer set on Fetch requests with a method of `HEAD` or `GET` (Firefox bug 1508661).
#### Media, Web Audio, and WebRTC
* The WebRTC `RTCIceCandidateStats` dictionary has been updated according to the latest spec changes (Firefox bug 1324788, Firefox bug 1489040; RTCIceCandidateStats has been updated to the latest spec for more details on exactly what has changed).
* The `MediaRecorder` `pause` and `resume` events (and their corresponding event handler properties were not previously implemented, even though compatibility tables claimed they had been. They have now been implemented (Firefox bug 1458538, Firefox bug 1514016).
#### Canvas and WebGL
* The WebGL `EXT_texture_compression_bptc` and `EXT_texture_compression_rgtc` texture compression extensions have been exposed to WebGL1 and WebGL2 contexts (Firefox bug 1507263).
#### Removals
* Mutation events have been disabled in shadow trees (Firefox bug 1489858).
* The non-standard `MediaStream` property `currentTime` has been removed (Firefox bug 1502927).
* The `dom.webcomponents.shadowdom.enabled` and `dom.webcomponents.customelements.enabled` prefs have been removed — Shadow DOM and Custom Elements can no longer be disabled in `about:config` (Firefox bug 1503019).
* The non-standard DOM `text` event — fired to notify the browser editor UI of IME composition string data and selection range — has been removed (Firefox bug 1288640).
* The `keypress` event is no longer fired for non-printable keys (Firefox bug 968056), except for the `Enter` key, and the `Shift` + `Enter` and `Ctrl` + `Enter` key combinations (these were kept for cross-browser compatibility purposes).
### Security
* Additional CORS restrictions are now being enforced on allowable request headers (Firefox bug 1483815, see also whatwg fetch issue 382: CORS-safelisted request headers should be restricted according to RFC 7231 for more details).
### Networking
*No changes.*
### Plugins
*No changes.*
### WebDriver conformance (Marionette)
#### API changes
* `WebDriver:ElementSendKeys` now handles `<input type=file>` more relaxed for interactability checks, and allows those elements to be hidden without raising a `not interactable` error anymore. If a strict interactability check is wanted the capability `strictFileInteractability` can be used (Firefox bug 1502864).
#### Bug fixes
* The window manipulation commands `WebDriver:FullscreenWindow`, `WebDriver:MinimizeWindow`, `WebDriver:MaximizeWindow`, and `WebDriver:SetWindowRect` have been made more stable (Firefox bug 1492499). It means that under special conditions they don't cause an infinite hang anymore, but instead timeout after 5s if the requested window state cannot be reached (Firefox bug 1521527).
* `WebDriver:ElementClick` now correctly calculates the center point of the element to click, which allows interactions with dimensions of 1x1 pixels (Firefox bug 1499360).
#### Others
* For `unexpected alert open` errors more informative messages are provided (Firefox bug 1502268).
### Other
* Support for WebP images has been added (Firefox bug 1294490).
+ In addition, to facilitate cross-browser compatibility in certain situations the WebP MIMEType (`image/webp`) has been added to the standard HTTP Request `Accept` header for HTML files (Firefox bug 1507691).
* The AV1 codec is now supported by default on Windows (Firefox bug 1452146).
Changes for add-on developers
-----------------------------
### API changes
#### Tabs
* The tabs API has been enhanced to support tab successors — a tab can have a successor assigned to it, which is the ID of the tab that will be active once it is closed (Firefox bug 1500479, also see this blog post for more information). In particular:
+ The `tabs.Tab` type now has a `successorId` property, which can be used to store/retrieve the ID of the tab's successor.
+ The `tabs.onActivated` event listener's callback has a new parameter available, `previousTabId`, which contains the ID of the previous activated tab, if it is still open.
+ The `tabs.update()` function's `updateProperties` object has a new optional property available on it, `successorTabId`, so can be used to update it.
+ `successorTabId` is also returned by functions like `tabs.get()` and `tabs.query()`.
+ The new function `tabs.moveInSuccession()` allows manipulation of tab successors in bulk.
### Manifest changes
*No changes.*
### Other
* The `headerURL`/`theme_frame` properties for WebExtension themes are now supported on Firefox for Android (Firefox bug 1429488).
See also
--------
* Hacks release post: Firefox 65: WebP support, Flexbox Inspector, new tooling & platform updates
Older versions
--------------
* Firefox 64 for developers
* Firefox 63 for developers
* Firefox 62 for developers
* Firefox 61 for developers
* Firefox 60 for developers
* Firefox 59 for developers
* Firefox 58 for developers
* Firefox 57 for developers
* Firefox 56 for developers
* Firefox 55 for developers
* Firefox 54 for developers
* Firefox 53 for developers
* Firefox 52 for developers
* Firefox 51 for developers
* Firefox 50 for developers
* Firefox 49 for developers
* Firefox 48 for developers
* Firefox 47 for developers
* Firefox 46 for developers
* Firefox 45 for developers
* Firefox 44 for developers
* Firefox 43 for developers
* Firefox 42 for developers
* Firefox 41 for developers
* Firefox 40 for developers
* Firefox 39 for developers
* Firefox 38 for developers
* Firefox 37 for developers
* Firefox 36 for developers
* Firefox 35 for developers
* Firefox 34 for developers |
Firefox 54 for developers - Mozilla | Firefox 54 for developers
=========================
Firefox 54 was released on June 13, 2017. This article lists key changes that are useful for web developers.
Changes for Web developers
--------------------------
### Developer Tools
* The network request summary now includes the amount of data actually transferred ("transferred size"), as does the performance analysis view (Firefox bug 1168376).
* The network request headers view now links to the related documentation on MDN (Firefox bug 1320233).
### CSS
* `clip-path` now supports basic shapes (Firefox bug 1247229).
* Firefox's implementations of CSS Flexbox and CSS alignment now implement updated spec language for interactions between the properties `align-items` and `align-self` as well as between `justify-items` and `justify-self` (Firefox bug 1340309).
* `<input>` elements of types `checkbox` and `radio` with `-moz-appearance``: none;` set on them are now non-replaced elements, for compatibility with other browsers (Firefox bug 605985).
* Previously, an element styled with `display`: `inline-block` with a child element of type `HTMLInputElement` styled with `display:block` had a wrong baseline (Firefox bug 1330962). This is now fixed.
* When Mozilla introduced dedicated content threads to Firefox (through the Electrolysis or e10s project), support for styling `<option>` elements was removed temporarily. Starting in Firefox 54, you can apply foreground and background colors to `<option>` elements again, using the `color` and `background-color` attributes. See Firefox bug 910022 for more information. Note that this is still disabled in Linux due to lack of contrast (see Firefox bug 1338283 for progress on this).
* CSS Animations now send the `animationcancel` event as expected when an animation aborts prematurely (Firefox bug 1302648).
* Transparent colors (i.e. those with an alpha channel of 0) were being serialized to the `transparent` color keyword in certain situations; this has been fixed so that Firefox follows the spec (as well as other browsers' implementations). See (Firefox bug 1339394 for further information.
* The proprietary `:-moz-table-border-nonzero` pseudo-class is no longer available to web content; it is now restricted to Firefox's internal UA stylesheet (Firefox bug 1341925).
* [css-grid] Intrinsic content with overflow:auto overlaps in grid (Firefox bug 1348857).
* [css-grid] Transferred min-size contribution of percentage size grid item with an intrinsic ratio (Firefox bug 1349320).
### JavaScript
* `\b` and `\B` in `RegExp` with the `"u"` (Unicode) and `"i"` (case insensitive) flags now treat U+017F (LATIN SMALL LETTER LONG S) and U+212A (KELVIN SIGN) as word characters (Firefox bug 1338373).
* The `DataView` constructor now throws a `RangeError` if the `byteOffset` parameter is out of `Number.MAX_SAFE_INTEGER` (>= 2 \*\* 53) (Firefox bug 1317382).
* The `Date.UTC()` method has been updated to conform to ECMAScript 2017 when fewer than two arguments are provided (Firefox bug 1050755).
* The `Function.prototype.toString()` method has been updated to match the latest proposed specification (Firefox bug 1317400).
### DOM & HTML DOM
* The `URL.toJSON()` method has been implemented (Firefox bug 1337702).
* The `URLSearchParams()` constructor now accepts a record containing strings as an init object (Firefox bug 1331580).
* Values returned in `KeyboardEvent.key` for printable keys when the control key is also pressed have been corrected on macOS (except when the Command key is pressed) (Firefox bug 1342865).
* The `dom.workers.latestJSVersion` preference, which was mainly implemented to work around problems using `let` in workers (due to Firefox bug 855665, which has since been fixed) has been removed (see Firefox bug 1219523).
* The `event.timeStamp` property now returns a high-resolution monotonic time (`DOMHighResTimeStamp`) instead of a value representing Unix time in milliseconds.
### Web Workers and Service Workers
* `WorkerGlobalScope.close` is now available on `DedicatedWorkerGlobalScope` and `SharedWorkerGlobalScope` instead. This change was made to stop `close()` being available on service workers, as it isn't supposed to be used there and always throws an exception when called (see Firefox bug 1336043).
* The `origin` property has been implemented (see Firefox bug 1306170).
* The `Client.type` property has been implemented (see Firefox bug 1339844).
* `Clients.matchAll()` now returns `Client` objects in most recently focused order (see Firefox bug 1266747).
* Some changes have been made to the observed behavior when the `Request()` constructor is passed an existing `Request` object instance to make a new instance. The following new behaviors are designed to retain security while making the constructor less likely to throw exceptions:
+ If this object exists on another origin to the constructor call, the `Request.referrer` is stripped out.
+ If this object has a `Request.mode` of `navigate`, the `mode` value is converted to `same-origin`.
### Audio/Video
#### General
* 5.1 surround sound playback is now enabled by default on Windows, macOS, and Linux (Firefox bug 1334508, Firefox bug 1321502, and Firefox bug 1323659).
#### Media Capture and Streams API
* Usage of a `MediaStream` object as the input parameter to `URL.createObjectURL()` has been deprecated — the console will now show a warning (see Firefox bug 1334564). You are advised to use `HTMLMediaElement.srcObject` instead.
#### Web Audio API
* The method `AnalyserNode.getFloatFrequencyData()` now correctly represents silent samples in the returned buffer with the value `-Infinity` (Firefox bug 1336098).
* `AudioParam.setValueCurveAtTime()` now throws a `TypeError` exception if any of the specified values aren't finite (Firefox bug 1308437).
#### Encrypted MediaExtensions API
* The `MediaKeySession.keySystem` string has been removed from the specification, and as such we've taken it out of Firefox 54 (Firefox bug 1335555).
* Support has been added for the VP9 codec in encrypted streams using Clear Key and Widevine (Firefox bug 1338064).
* Previously, MSE was only allowed to use WebM/VP8 video if the system was considered "fast enough." Now playback of VP8-encoded `webm/video` media is always supported, regardless of system performance.
#### WebRTC
* TCP ICE candidate support, originally added in Firefox 41, is now enabled by default. This allows the ICE layer to consider candidates that use TCP rather than the preferred UDP for transmission. This can be useful in environments in which UDP is blocked (Firefox bug 1176382). This blog post explains the feature in more details.
Removals from the web platform
------------------------------
### CSS
* Removed the `-moz` prefixed versions of `isolate`, `isolate-override`, and `plaintext` values for the `unicode-bidi` property (Firefox bug 1333675).
### HTTP
* HTTP/1 Pipelining support has been removed in Firefox 54. Maintaining it as we make the move into a new world full of HTTP/2 and other substantial, standardized improvements to networking performance is not worthwhile given pipelining's compatibility and performance issues. The `network.http.pipelining` preference (as well as the other preferences that start with "network.http.pipelining") is now ignored. See Firefox bug 1340655 for further information.
Older versions
--------------
* Firefox 53 for developers
* Firefox 52 for developers
* Firefox 51 for developers
* Firefox 50 for developers
* Firefox 49 for developers
* Firefox 48 for developers
* Firefox 47 for developers
* Firefox 46 for developers
* Firefox 45 for developers
* Firefox 44 for developers
* Firefox 43 for developers
* Firefox 42 for developers
* Firefox 41 for developers
* Firefox 40 for developers
* Firefox 39 for developers
* Firefox 38 for developers
* Firefox 37 for developers
* Firefox 36 for developers
* Firefox 35 for developers
* Firefox 34 for developers
* Firefox 33 for developers
* Firefox 32 for developers
* Firefox 31 for developers
* Firefox 30 for developers
* Firefox 29 for developers
* Firefox 28 for developers
* Firefox 27 for developers
* Firefox 26 for developers
* Firefox 25 for developers
* Firefox 24 for developers
* Firefox 23 for developers |
Firefox 48 for developers - Mozilla | Firefox 48 for developers
=========================
To test the latest developer features of Firefox, install Firefox Developer Edition Firefox 48 was released on August 2, 2016. This article lists key changes that are useful not only for web developers, but also Firefox and Gecko developers as well as add-on developers.
Changes for Web developers
--------------------------
### Developer Tools
* The position of elements can now be changed within the content (Firefox bug 1139187).
* Implemented `console.clear()` to clear the console output (Firefox bug 659625).
* Added HTTP log inspection to the Web Console (Firefox bug 1211525).
* Added a Firebug theme (Firefox bug 1244054).
* Added the DOM Inspector (Firefox bug 1201475).
* Font inspector has been enabled by default again (Firefox bug 1280121).
* Improved suggestions for CSS properties (Firefox bug 1168246).
* Cookies, localstorage and sessionstorage entries are editable via double-click (Firefox bug 1231154, Firefox bug 1231179, Firefox bug 1231155).
### HTML
* The `<details>` and `<summary>` elements have been activated by default on Nightly and Aurora (DevTools), but not on Beta or Release:
+ The default style for these elements has been adapted to match the spec (Firefox bug 1258657).
+ The `toggle` event is now sent to the `<details>` element when this one is opened or closed (Firefox bug 1225412).
* The `meta` attributes now also supports the `no-referrer-when-downgrade` and `origin-when-cross-origin` values (Firefox bug 1178337).
### CSS
* The `calc()` has been improved to be closer to the specification:
+ `calc()` is now supported on the `line-height` property (Firefox bug 594933).
+ Added support for nested CSS `calc()` (Firefox bug 968761).
* Our experimental implementation of CSS grids has been updated:
+ Fragmentation for grid layout has been implemented (Firefox bug 1144096).
+ [css-grid] Percentage tracks are now treated as `auto` if grid container size is indefinite (Firefox bug 1264607).
+ `<fieldset>` now supports grid and flex layouts (Firefox bug 1230207).
* The `luminance` value for `mask-mode` has been added; the `auto` value has been renamed to `match-source`, to match the spec (Firefox bug 1228354).
* Interpolation of `clip-path` basic shapes in CSS animations and transitions is now supported (Firefox bug 1110460).
* Support for horizontal-in-vertical (*tate-chu-yoko*) text has been added via the `all` value of the `text-combine-upright` property (Firefox bug 1097499).
* Support for the experimental `color-adjust` property has been added, allowing pages to specify that background colors and images should be printed (Firefox bug 1209273).
* The `::first-letter` pseudo-element now also matches punctuation characters of type Pd that precede or immediately follow the actual first letter; this is a new requirement of CSS Pseudo-element module level 4 (Firefox bug 1260366).
* Several `-webkit` prefixed properties and values have been added for web compatibility, behind the preference `layout.css.prefixes.webkit`, defaulting to `false`:
+ `-webkit-text-fill-color` (Firefox bug 1247777).
+ `-webkit-text-stroke`, `-webkit-text-stroke-color`, `-webkit-text-stroke-width` (Firefox bug 1248708).
+ `-webkit-background-clip` (as background-clip) text value (Firefox bug 759568).
+ `-webkit-box-direction`, `-webkit-box-orient` (Firefox bug 1262049.
+ The value `-webkit-inline-box` is now an alias of `inline-flex` on the `display` property. (Firefox bug 1257661).
+ `-webkit-flex-direction`, `-webkit-flex-wrap`, `-webkit-flex-flow`, `-webkit-order`, `-webkit-flex`, `-webkit-flex-grow`, `-webkit-flex-shrink`, `-webkit-flex-basis`, `-webkit-justify-content`, `-webkit-align-items`, `-webkit-align-self` and `-webkit-align-content` were added as aliases for the unprefixed properties and the values `-webkit-flex` and `-webkit-inline-flex` for the `display` property as aliases for the unprefixed values (Firefox bug 1274096).
+ Added `-webkit-box-flex`, `-webkit-box-ordinal-group`, `-webkit-box-align` and `-webkit-box-pack` properties and `-webkit-box` value to `display` as aliases for modern CSS Flexbox (Firefox bug 1208635).
* The `text` value of `background-clip` is now available in all type of Firefox (and not only non-release builds) (Firefox bug 1263516).
* The `absolute` value of `position` properties on the top layer element (Firefox bug 1236828).
* Added an internal-only syntax for `@supports` to detect pref (Firefox bug 1259889).
### JavaScript
#### New APIs
* The `String.prototype.padStart()` and `String.prototype.padEnd()` methods have been implemented (Firefox bug 1260509).
* The ES2015 `Symbol.unscopables` and `Array.prototype[@@unscopables]` properties have been implemented (Firefox bug 1054759 and Firefox bug 1258163).
* The ES2015 `Symbol.isConcatSpreadable` symbol has been implemented (Firefox bug 1041586).
* The ES2015 `Array[@@species]` getter has been implemented (Firefox bug 1165052).
* The ES2015 `ArrayBuffer[@@species]` getter and `%TypedArray%[@@species]` getter have been implemented (Firefox bug 1165053).
* The `Intl.getCanonicalLocales()` method of the ECMAScript Internationalization API draft has been implemented (Firefox bug 1263040).
#### Deprecations and removals
* The deprecated old Proxy API (`Proxy.create` and `Proxy.createFunction()`) has been removed. Use the standard `Proxy` object instead (Firefox bug 892903).
* The `String.prototype.contains()` method has been removed (it was deprecated since version 40). Use the `String.prototype.includes()` method instead (Firefox bug 1103588).
* The non-standard `RegExp.multiline` property (not `RegExp.prototype.multiline`) has been removed. Use the standard m flag instead (Firefox bug 1219757).
* The `Object.prototype.__defineGetter__()` and `Object.prototype.__defineSetter__()` methods can no longer be called at the global scope without any object. (Firefox bug 1253016).
### Interfaces/APIs/DOM
#### DOM & HTML DOM
* Dropped the "Moz" prefix from the `CSSKeyframeRule` and `CSSKeyframesRule` interfaces (Firefox bug 1256178).
* The `NavigatorConcurrentHardware` mixin has been implemented, which adds the `Navigator.hardwareConcurrency` property to the `Navigator` interface. This lets websites and apps get at least an approximation of how many processing cores are available to run `Worker`s in (Firefox bug 1008453).
* The `Node.isSameNode()` method, which was removed in Firefox 10, has returned after being added back into the specification after a lengthy absence (Firefox bug 1256299).
* Firefox now returns proper exceptions instead of numbers when things go wrong during a call to `Navigator.registerProtocolHandler()`.
* `Element.animate()` is now activated by default (Firefox bug 1245000).
* The two methods `Element.insertAdjacentText()` and `Element.insertAdjacentElement()` have been implemented (Firefox bug 811259).
* `Document.scrollingElement` got enabled by default (Firefox bug 1265032).
* `Node.localName`, `Node.namespaceURI` and `Node.prefix` were moved to the `Element` and `Attr` APIs (Firefox bug 1055776).
* Per the latest specification, the values of `KeyboardEvent.code` returned for the following keys have been changed see (Firefox bug 1264150):
+ `"OSLeft"` and `"OSRight"` are now `"MetaLeft"` and `"MetaRight"`.
+ `"VolumeDown"`, `"VolumeUp"`, and `"VolumeMute"` are now `"AudioVolumeDown"`, `"AudioVolumeUp"`, and `"AudioVolumeMute"`.
+ `"IntlHash"` has been removed.
+ All keys whose `code` values were reported as "" in earlier versions of Firefox are now reported as "Unidentified".
#### Canvas 2D
* The `CanvasRenderingContext2D.ellipse()` method has been implemented (Firefox bug 910138).
#### WebRTC
* The two methods `MediaStream.clone()` and `MediaStreamTrack.clone()` have been implemented (Firefox bug 1208371).
* The `iceRestart` entry is now supported in the `RTCOfferOptions` code dictionary, allowing `createOffer()` to be used to request ICE restarts (Firefox bug 906986).
* The `RTCPeerConnection.createOffer()` method now prefers the VP9 video codec by default; previously VP8 was preferred (Firefox bug 1242324.
* WebM/VP8 video that includes video resolution changes that has been recorded using `MediaRecorder` can now be played back successfully.
#### Others
* The Web Crypto API is now available in Web workers (Firefox bug 842818).
* The `CustomEvent` interface is now available in Web Workers (Firefox bug 1003432).
* The `DOMApplicationsManager.getNotInstalled()` method has been removed (Firefox bug 1255036).
* Several Firefox OS APIs that were erroneously exposed to the Web have now been hidden as they should have been — `mozContact`, `MozContactChangeEvent`, `navigator.mozContacts`, `MozPowerManager`, `MozSettingsEvent` (see Firefox bug 1043562, Firefox bug 1256414, and Firefox bug 1256046).
* Support for UTF-16 has been removed from `TextEncoder` (Firefox bug 1257877).
* `RTCStatsReport` is now a true `maplike` interface: in addition to `forEach()`, `get()`, and `has()`, the methods `entries()`, `values()`, `keys()`, as well as the `size` getter have been implemented (Firefox bug 906986).
* The `Request.cache` property has been added allowing to control the cache behavior (Firefox bug 1120715).
* Handling of dead keys on Mac OS X has been changed to work the same as other platforms; they no longer fire a `keypress` event when no text is generated when the focused element isn't editable (when the focused element is editable, dead key causes composition events instead of keyboard events on Mac OS X). Also, like on other platforms, the value of `KeyboardEvent.key` is now `"Dead"` for dead keypresses which don't generate text in other situations.
HTTP
----
* Support for the `Upgrade-Insecure-Requests` header has been added (Firefox bug 1243586).
* The `block-all-mixed-content` CSP directive has been implemented (Firefox bug 1122236)
Changes for add-on and Mozilla developers
-----------------------------------------
* The Social Worker API has been removed.
* Added the `-moz-bool-pref()` CSS `@supports` function to allow hiding portions of chrome stylesheets behind boolean preferences. (Firefox bug 1259889)
Older versions
--------------
* Firefox 47 for developers
* Firefox 46 for developers
* Firefox 45 for developers
* Firefox 44 for developers
* Firefox 43 for developers
* Firefox 42 for developers
* Firefox 41 for developers
* Firefox 40 for developers
* Firefox 39 for developers
* Firefox 38 for developers
* Firefox 37 for developers
* Firefox 36 for developers
* Firefox 35 for developers
* Firefox 34 for developers
* Firefox 33 for developers
* Firefox 32 for developers
* Firefox 31 for developers
* Firefox 30 for developers
* Firefox 29 for developers
* Firefox 28 for developers
* Firefox 27 for developers
* Firefox 26 for developers
* Firefox 25 for developers
* Firefox 24 for developers
* Firefox 23 for developers
* Firefox 22 for developers
* Firefox 21 for developers
* Firefox 20 for developers
* Firefox 19 for developers
* Firefox 18 for developers
* Firefox 17 for developers |
Firefox 102 for developers - Mozilla | Firefox 102 for developers
==========================
This article provides information about the changes in Firefox 102 that will affect developers. Firefox 102 was released on June 28, 2022.
Changes for web developers
--------------------------
### HTML
No notable changes.
### CSS
The `update` media feature that can be used to query the ability of the output device to modify the appearance of content after it is rendered is now available by default (Firefox bug 1422312).
### JavaScript
No notable changes.
### APIs
* The non-standard interfaces `IDBMutableFile`, `IDBFileHandle`, `IDBFileRequest`, and the method `IDBDatabase.createMutableFile()` have been disabled by default in preparation for removal in a future release (Firefox bug 1764771).
* Transform streams are now supported, allowing you to pipe from `ReadableStream` to a `WritableStream`, executing a transformation on the chunks.
The update includes the new interfaces `TransformStream` and `TransformStreamDefaultController` and the method `ReadableStream.pipeThrough()` (Firefox bug 1767507).
* Readable byte streams are now supported, allowing efficient zero-byte transfer of data from an underlying byte source to a consumer (bypassing the stream's internal queues).
The new interfaces are `ReadableStreamBYOBReader`, `ReadableByteStreamController` and `ReadableStreamBYOBRequest` (Firefox bug 1767342).
### Security
* Support of the `wasm-unsafe-eval` CSP policy directive has been implemented.
A document with a CSP that restricts scripts will no longer load and execute WebAssembly unless the CSP uses `'wasm-unsafe-eval'` or the existing `'unsafe-eval'` keyword (Firefox bug 1740263).
#### DOM
* The Firefox-only property `Window.sidebar` has been moved behind a preference (and permanently removed in version 119) (Firefox bug 1768486).
### WebDriver conformance
#### WebDriver BiDi
* There are some improvements to Webdriver BiDi's `browsingContext.navigate`
+ Fixed edge cases where the navigation could incorrectly timeout (Firefox bug 1766217).
+ Added support for hash changes (Firefox bug 1763127).
+ Added support navigation to error pages (Firefox bug 1763124).
#### Marionette
* Allow marionette to connect to a windowless instance of Firefox (Firefox bug 1726465).
* Fixed issue where `WebDriver:Navigate` with a PageLoadStrategy of "none" returns before navigation has started (Firefox bug 1754132).
* Fixed a potential race condition in `WebDriver:SwitchToWindow` when switching to a different tab (Firefox bug 1749666).
Changes for add-on developers
-----------------------------
* The `scripting` API, which provides features to execute script, insert and remove CSS, and manage the registration of content scripts is available to Manifest V2 extensions (Firefox bug 1766615).
* The `nonPersistentCookies` option of the `privacy.websites` `cookieConfig` property has been deprecated (Firefox bug 1754924).
* Manifest V3 preview features:
+ With the introduction of support for the 'wasm-unsafe-eval' CSP keyword in Firefox (Firefox bug 1740263), Manifest V3 extensions are now required to specify this keyword in the content\_security\_policy manifest key to use WebAssembly. For backwards-compatibility, Manifest V2 extensions can still use WebAssembly without the keyword (Firefox bug 1766027).
Older versions
--------------
* Firefox 101 for developers
* Firefox 100 for developers
* Firefox 99 for developers
* Firefox 98 for developers
* Firefox 97 for developers
* Firefox 96 for developers
* Firefox 95 for developers
* Firefox 94 for developers
* Firefox 93 for developers
* Firefox 92 for developers
* Firefox 91 for developers
* Firefox 90 for developers
* Firefox 89 for developers
* Firefox 88 for developers
* Firefox 87 for developers
* Firefox 86 for developers
* Firefox 85 for developers
* Firefox 84 for developers
* Firefox 83 for developers
* Firefox 82 for developers
* Firefox 81 for developers
* Firefox 80 for developers
* Firefox 79 for developers
* Firefox 78 for developers
* Firefox 77 for developers
* Firefox 76 for developers
* Firefox 75 for developers
* Firefox 74 for developers
* Firefox 73 for developers
* Firefox 72 for developers
* Firefox 71 for developers |
Firefox 90 for developers - Mozilla | Firefox 90 for developers
=========================
This article provides information about the changes in Firefox 90 that will affect developers. Firefox 90 was released on July 13th, 2021.
**Note:** See also Getting lively with Firefox 90 on Mozilla Hacks.
Changes for web developers
--------------------------
### Developer Tools
* The response view now shows a preview for web fonts (Firefox bug 872078).
### HTML
* A fix to the way that form payloads are handled around newline normalization and escaping in multipart/formdata. This meets the updated specification, and matches other browser implementations. (Firefox bug 1686765).
* Firefox now sets an image's intrinsic size and resolution based on EXIF information (if present and self-consistent). This allows a server to, for example, send a low-quality placeholder image to speed up loading. It also enables a number of other use cases (Firefox bug 1680387).
### CSS
* `-webkit-image-set()` has been implemented as an alias of the standard `image/image-set()` function (Firefox bug 1709415).
### JavaScript
* Private class static and instance fields and methods are now supported by default (Firefox bug 1708235 and Firefox bug 1708236).
* The `in` operator can now be used to check if a class private method or field has been defined. This offers a more compact approach for handling potentially undefined features, as oppose to wrapping code in `try/catch` blocks (Firefox bug 1648090).
* Custom date/time formats specified as options to the `Intl.DateTimeFormat()` constructor can now include `dayPeriod` — a value indicating that the approximate time of day (e.g. "in the morning", "at night", etc.) should be included as a `narrow`, `short`, or `long` string (Firefox bug 1645115).
* The relative indexing method `at()` has been added to the `Array`, `String` and `TypedArray` global objects. (Firefox bug 1681371)
### HTTP
* The HTTP fetch metadata request headers (`Sec-Fetch-*`) are now supported. These headers provide servers with additional context about requests, including whether they are same-origin, cross-origin, same-site, or user-initiated, and where/how the requested data is to be used. This allows servers to mitigate against several types of cross-origin attacks (Firefox bug 1695911).
#### Removals
* FTP has now been removed from Firefox (Firefox bug 1574475). This follows deprecation in Firefox 88. Note that web extensions can still register themselves as FTP protocol handlers.
### APIs
#### DOM
* Support was added for the deprecated `WheelEvent` properties: `WheelEvent.wheelDelta`, `WheelEvent.wheelDeltaX`, and `WheelEvent.wheelDeltaY`. This allows Firefox to work with a small subset of pages that were broken by recent compatibility improvements to `WheelEvent` (Firefox bug 1708829).
* The `CanvasRenderingContext2D` interface of the `Canvas API` now provides a `createConicGradient()` method. This returns a `CanvasGradient` much like the existing `linear` and `radial` gradients, but allows a gradient to move around a point defined by coordinates. See Firefox bug 1627014 for more details.
* Support for the `matrix` protocol has been added and can now be passed into the `Navigator.registerProtocolHandler()` method as a valid scheme.
### WebDriver conformance (Marionette)
* Marionette now restricts to a single active WebDriver session (Firefox bug 1691047).
* Added support for the new type of user prompts in Firefox (Firefox bug 1686741)
* Window handles make use of a unique id now, and don't change for process
swaps as caused by cross-group navigations (Firefox bug 1680479).
* Fixed an inappropriate abortion of the current WebDriver command when a
new user prompt was opened in a background tab (Firefox bug 1701686).
* Fixed the `WebDriver:GetWindowHandles` command to now correctly
handle unloaded tabs (Firefox bug 1682062).
* Fixed the `WebDriver:NewSession` command to always return the
`proxy` capability even if empty (Firefox bug 1710935).
#### Removals
* With the removal of the FTP support in Firefox 90
the `ftpProxy` capability is no longer evaluated, and when used will
throw an `invalid argument` error (Firefox bug 1703805).
Changes for add-on developers
-----------------------------
* The `matrix` URI scheme is now supported and can be defined as a protocol within the `protocol_handlers` key in an extensions `manifest.json`
* Starting with this version, the Cache API can be used in the extension pages and worker globals. For more details, see (Firefox bug 1575625).
Older versions
--------------
* Firefox 89 for developers
* Firefox 88 for developers
* Firefox 87 for developers
* Firefox 86 for developers
* Firefox 85 for developers
* Firefox 84 for developers
* Firefox 83 for developers
* Firefox 82 for developers
* Firefox 81 for developers
* Firefox 80 for developers
* Firefox 79 for developers
* Firefox 78 for developers
* Firefox 77 for developers
* Firefox 76 for developers
* Firefox 75 for developers
* Firefox 74 for developers
* Firefox 73 for developers
* Firefox 72 for developers
* Firefox 71 for developers
* Firefox 70 for developers
* Firefox 69 for developers
* Firefox 68 for developers
* Firefox 67 for developers
* Firefox 66 for developers
* Firefox 65 for developers
* Firefox 64 for developers
* Firefox 63 for developers
* Firefox 62 for developers
* Firefox 61 for developers
* Firefox 60 for developers
* Firefox 59 for developers |
Firefox 32 for developers - Mozilla | Firefox 32 for developers
=========================
Changes for Web developers
--------------------------
### Developer Tools
Highlights:
* Web Audio Editor
* *Code completion and inline documentation in Scratchpad]*
* User agent styles in the Inspector's Rules view
* Element picker button has moved
* Node dimensions added to the Inspector's infobar
* Full page screenshot button added
* HiDPI images added to the tools
* Nodes that have `display:none` are shown differently in the Inspector
All devtools bugs fixed between Firefox 31 and Firefox 32.
### CSS
* Enabled `mix-blend-mode` by default (Firefox bug 952643).
* Enabled `position:sticky` by default in release builds (only enabled on Nightly and Aurora before) (Firefox bug 916315).
* Implemented `box-decoration-break` and removed the non-standard `-moz-background-inline-policy` (Firefox bug 613659).
* Allowed `flex-grow` and `flex-shrink` to transition between zero and nonzero values, like 'flex-grow: 0.6'(Firefox bug 996945).
### HTML
* Experimentally implemented, behind a pref, `<img>` `srcset` property, To activate it set `dom.image.srcset.enable` to `true` (Firefox bug 870021).
* **id** and **class** are now true global attributes and also apply to XML elements, in a namespace or not (Firefox bug 741295).
### JavaScript
* The following new ECMAScript 2015 built-in methods got implemented:
+ `Array.from()` (Firefox bug 904723),
+ `Array.prototype.copyWithin()` (Firefox bug 934423),
+ `Number.isSafeInteger()` (Firefox bug 1003764).
### Interfaces/APIs/DOM
* The `Navigator.languages` property and `languagechange` event have been implemented (Firefox bug 889335).
* The `Navigator.vibrate()` method behavior has been adapted to the latest specification: too long vibrations are now truncated (Firefox bug 1014581).
* The `KeyboardEvent.getModifierState()` and `MouseEvent.getModifierState()` methods have been extended to support the `Accel` virtual modifier (Firefox bug 1009388).
* The `KeyboardEvent.code` property have been experimentally implemented: it is disabled on release build (Firefox bug 865649).
* Scoped selectors for `Document.querySelector()` and `Document.querySelectorAll()`, for example `querySelector(":scope > li")` have been implemented (Firefox bug 528456).
* The experimental implementation of the `Document.timeline` interface, related to the Web Animation API, has been added (Firefox bug 998246). It is controlled by `layout.web-animations.api.enabled` preference, enabled only on Nightly and Aurora for the moment.
* The Data Store API has been made available to Web Workers (Firefox bug 949325). It still is only activated for certified applications.
* The ServiceWorker `InstallPhaseEvent` and `InstallEvent` interfaces have been implemented (Firefox bug 967264).
* The MSISDN Verification API, only activated for privileged apps, has been added (Firefox bug 988469).
* The Gamepad API is now supported on Firefox for Android (Firefox bug 852935).
* To match the spec and the evolution of the CSS syntax, minor changes have been done to `CSS.escape()`. The identifier now can begins with `'--'` and the second dash must not be escaped. Also vendor identifier are no more escaped. (Firefox bug 1008719)
* To complete our Hit Regions implementation, `MouseEvent.region` has been implemented (Firefox bug 979692).
* The `CanvasRenderingContext2D.drawFocusIfNeeded()` method is now enabled by default (Firefox bug 1004579).
* The `Navigator.doNotTrack` properties now returns `'1'` or `'0'`, reflecting the HTTP value, instead of `'yes'` or `'no'` (Firefox bug 887703).
* XMLHttpRequest.responseURL was implemented (Firefox bug 998076)..
### MathML
* Add support for the `<menclose>` notation `phasorangle`.
### SVG
*No change.*
### WebRTC
* New constraints for WebRTC's `getUserMedia()`, `width`, `height`, and `framerate`, have been added, to limit stream dimensions and frame rate (Firefox bug 907352):
```js
{
mandatory: {
width: { min: 640 },
height: { min: 480 },
},
optional: [
{ width: 650 },
{ width: { min: 650 }},
{ frameRate: 60 },
{ width: { max: 800 }},
]
}
```
* WebRTC methods which previously used callback functions as input parameters are now also available using JavaScript promises.
### Audio/Video
*No change.*
Security
--------
* Privileged code now gets Xray vision for JavaScript `Object` and `Array` instances.
Changes for add-on and Mozilla developers
-----------------------------------------
Xray vision is now applied to JavaScript objects that are not themselves DOM objects: Xrays for JavaScript objects.
A `getDataDirectory()` method has been added to `Addon` instances. This method returns the preferred location, within the current profile, for add-ons to store data.
### Add-on SDK
#### Highlights
* Added `exclude` option to `PageMod`.
* Added `anonymous` option to `Request`.
* Add-on Debugger now includes a Console and a Scratchpad.
#### Details
GitHub commits made between Firefox 31 and Firefox 32. This will not include any uplifts made after this release entered Aurora.
Bugs fixed between Firefox 31 and Firefox 32. This will not include any uplifts made after this release entered Aurora.
### XPCOM
* The `nsIUDPSocket` interface now provides multicast support through the addition of the new `nsIUDPSocket.multicastLoopback`, `nsIUDPSocket.multicastInterface`, and `nsIUDPSocket.multicastInterfaceAddr` attributes, as well as the `nsIUDPSocket.joinMulticast()` and `nsIUDPSocket.leaveMulticast()` methods.
### Older versions
* Firefox 31 for developers
* Firefox 30 for developers
* Firefox 29 for developers
* Firefox 28 for developers
* Firefox 27 for developers
* Firefox 26 for developers
* Firefox 25 for developers
* Firefox 24 for developers
* Firefox 23 for developers
* Firefox 22 for developers
* Firefox 21 for developers
* Firefox 20 for developers
* Firefox 19 for developers
* Firefox 18 for developers
* Firefox 17 for developers
* Firefox 16 for developers
* Firefox 15 for developers
* Firefox 14 for developers
* Firefox 13 for developers
* Firefox 12 for developers
* Firefox 11 for developers
* Firefox 10 for developers
* Firefox 9 for developers
* Firefox 8 for developers
* Firefox 7 for developers
* Firefox 6 for developers
* Firefox 5 for developers
* Firefox 4 for developers
* Firefox 3.6 for developers
* Firefox 3.5 for developers
* Firefox 3 for developers
* Firefox 2 for developers
* Firefox 1.5 for developers |
Firefox 79 for developers - Mozilla | Firefox 79 for developers
=========================
This article provides information about the changes in Firefox 79 that will affect developers. Firefox 79 was released on July 28, 2020.
See also Firefox 79: The safe return of shared memory, new tooling, and platform updates on Mozilla hacks.
Changes for web developers
--------------------------
### Developer Tools
#### Console
* Network messages with response codes in the 400-499 and 500-599 ranges are now considered errors, and are displayed even if Response or XHR filters are disabled. (Firefox bug 1635460)
* Network messages for requests that are blocked (by the browser or an extension) are now styled with a "prohibited" icon in the Console. (Firefox bug 1629875)
#### Debugger
* "Blackbox" a source file is now called "ignore" a source file. (Firefox bug 1642811)
* Inline preview is now available on exceptions. (Firefox bug 1581708)
* Items in the Watch Expressions and Scopes sections now have tooltips on hover, showing their values (Firefox bug 1631545)
* In the Call Stack section, there is now a context menu option to **Restart Frame**, to execute the current stack frame from its beginning. (Firefox bug 1594467)
#### Other tools
* The new Application panel is now available, which initially provides inspection and debugging support for service workers and web app manifests.
* The Messages tab of the Network Monitor has been merged with the Responses tab. (Firefox bug 1636421)
* The Accessibility Inspector is automatically turned on when you access its tab; you no longer need to explicitly enable it. (Firefox bug 1602075)
* In Responsive Design Mode, when touch simulation is enabled, mouse-drag events are now interpreted as touch-drag or swipe events. (Firefox bug 1621781)
* When remote debugging, the URL bar now has **Back** and **Forward** buttons to help with navigation on the remote browser. (Firefox bug 1639425)
### HTML
* The `<iframe>` element's `sandbox` attribute now supports the `allow-top-navigation-by-user-activation` token (Firefox bug 1359867).
* Setting `target="_blank"` on `<a>` and `<area>` elements implicitly provides the same behavior as also setting `rel="noopener"` (Firefox bug 1522083).
### CSS
* External style sheets are now cached per document group (Firefox bug 1599160). Firefox will minimize retrieval and revalidation of cached style sheets when navigating pages on the same origin. A simple reload (for example, `F5`) will not revalidate the cached CSS files. To load current versions of the style sheets, reload the page bypassing the cache (`Cmd`/`Ctrl` + `F5`).
#### Removals
* The `prefers-color-scheme` media feature's `no-preference` value has been removed from the media queries spec, and from Firefox (Firefox bug 1643656).
### JavaScript
* `SharedArrayBuffer` has been re-enabled in a post-Spectre-safe manner. It is available to cross-origin isolated sites (Firefox bug 1619649).
+ To cross-origin isolate your site, you need to set the new `Cross-Origin-Embedder-Policy` (COEP) and `Cross-Origin-Opener-Policy` (COOP) headers.
* `Promise.any()` is now available (Firefox bug 1599769).
* `WeakRef` objects have been implemented (Firefox bug 1639246).
* Logical assignment operators are now supported (Firefox bug 1639591)
+ Logical nullish assignment (`??=`)
+ Logical AND assignment (`&&=`)
+ Logical OR assignment (`||=`)
* `Atomics` objects now also work with non-shared memory (Firefox bug 1630706).
* The `Intl.DateTimeFormat()` constructor now supports the `dateStyle` and `timeStyle` options (Firefox bug 1557718).
* The `Intl.NumberFormat()` constructor now supports more numbering systems (Firefox bug 1413504).
### HTTP
* Cross-origin isolation has been implemented using the new `Cross-Origin-Embedder-Policy` (COEP) and `Cross-Origin-Opener-Policy` (COOP) headers. This allows you to access certain features such as `SharedArrayBuffer` objects and unthrottled timers in `Performance.now()`.
### APIs
#### DOM
* The `FileReader` interface's `loadstart` event is now dispatched asynchronously, as per the spec (Firefox bug 1502403).
* `CanvasPattern.setTransform()` now supports a `DOMMatrix` object as an input parameter, as well as an `SVGMatrix` object (Firefox bug 1565997).
#### Media, WebRTC, and Web Audio
* Firefox now supports remote timestamps on statistics records whose `RTCStats.type` is `remote-outbound-rtp`. The `RTCRemoteOutboundRtpStreamStats` dictionary which is used to provide these statistics now includes the `remoteTimestamp` property, which states the timestamp on the remote peer at which the statistics were collected or generated (Firefox bug 1615191).
#### Removals
* A number of internal Gecko events — including `DOMWindowClose` — which were accidentally exposed to the web, are now internal-only as intended (Firefox bug 1557407).
### WebAssembly
* WebAssembly Bulk memory operations are now shipped (Firefox bug 1528294).
* WebAssembly Reference types are now shipped (Firefox bug 1637884).
* WebAssembly Threads (Shared memory & Atomics) are now shipped (Firefox bug 1389458, Firefox bug 1648685).
Changes for add-on developers
-----------------------------
* New API: `tabs.warmup()` (bug 1402256)
* Storage quotas are now enforced for the `sync` storage area (bug 1634615) (addons.mozilla.org blog post)
Older versions
--------------
* Firefox 78 for developers
* Firefox 77 for developers
* Firefox 76 for developers
* Firefox 75 for developers
* Firefox 74 for developers
* Firefox 73 for developers
* Firefox 72 for developers
* Firefox 71 for developers
* Firefox 70 for developers
* Firefox 69 for developers
* Firefox 68 for developers
* Firefox 67 for developers
* Firefox 66 for developers
* Firefox 65 for developers
* Firefox 64 for developers
* Firefox 63 for developers
* Firefox 62 for developers
* Firefox 61 for developers
* Firefox 60 for developers
* Firefox 59 for developers
* Firefox 58 for developers
* Firefox 57 for developers
* Firefox 56 for developers
* Firefox 55 for developers
* Firefox 54 for developers
* Firefox 53 for developers
* Firefox 52 for developers
* Firefox 51 for developers
* Firefox 50 for developers
* Firefox 49 for developers
* Firefox 48 for developers |
Firefox 50 for developers - Mozilla | Firefox 50 for developers
=========================
To test the latest developer features of Firefox, install Firefox Developer EditionFirefox 50 was released on November 15, 2016. This article lists key changes that are useful not only for web developers, but also Firefox and Gecko developers as well as add-on developers.
Changes for Web developers
--------------------------
### HTML
* The default style of `<bdo>` now sets `unicode-bidi` with the `isolate-override` value (Firefox bug 1249497).
* Setting the `<track>` element's `src` attribute now works correctly (Firefox bug 1281418).
* The `referrerpolicy` attribute on `<area>`, `<a>`, `<img>`, `<iframe>` and `<link>` elements is now available by default (Firefox bug 1223838, Firefox bug 1264165).
### CSS
* Border-radiused corners with dashed and dotted styles are now rendered with the specified style instead of a solid style (Firefox bug 382721).
* The non-standard `:-moz-full-screen-ancestor` pseudo-class selector has been removed (Firefox bug 1199529).
* The `box-sizing``: padding-box` has been removed, since it's no longer a part of the spec and Firefox was the only major browser implementing it (Firefox bug 1166728).
* The three values `isolate`, `isolate-override`, and `plaintext` of the `unicode-bidi` property have been unprefixed (Firefox bug 1141895).
* In quirks mode, the bullet of a list item now inherits the size of the list, like in standards mode (Firefox bug 648331).
* The `:in-range` and `:out-of-range` pseudo-classes have changed behavior to not match disabled or read-only inputs (Firefox bug 1264157).
* The `:any-link` pseudo-class is now unprefixed (Firefox bug 843579).
* The `space` value for `border-image-repeat` has been implemented (Firefox bug 720531).
### JavaScript
* The ES2015 `Symbol.hasInstance` property has been implemented (Firefox bug 1054906).
* The ES2017 `Object.getOwnPropertyDescriptors()` method has been implemented (Firefox bug 1245024).
* The behavior of \W in `RegExp` with unicode and ignoreCase flags is changed to match recent draft spec. Now it doesn't match to K, S, k, s, and KELVIN SIGN (U+212A), and LATIN SMALL LETTER LONG S (U+017F) (Firefox bug 1281739).
### Developer Tools
* The Web Console now understands source maps.
* The Storage Inspector now lets you delete individual items from IndexedDB object stores.
* The Memory tool is enabled by default.
* The Box model view is moved into the Computed view.
* The Web Console now displays stack traces for XHR or Fetch() network requests.
All devtools bugs fixed between Firefox 49 and Firefox 50.
### HTTP
* The experimental (and deprecated) SPDY 3.1 is now disabled by default Firefox bug 1287132.
* Support for `X-Content-Type-Options` has been added (Firefox bug 471020).
* The cookie prefixes `__Host-` and `__Secure-` have been implemented. See `Set-Cookie` and Firefox bug 1283368.
* The `Referrer-Policy` header has been implemented Firefox bug 1264164.
### Security
* The `ping` attribute of `<a>` element now abides by the `connect-src` CSP 1.1 policy directive (Firefox bug 1100181).
* Support for the `sandbox` CSP directive has been added (Firefox bug 671389).
* It's now possible to set a content security policy for workers (Firefox bug 959388).
* The `Navigator.sendBeacon()` method no longer throws an exception if the beacon data couldn't be sent due to a Content Security Policy restriction; instead, it returns `false` as expected (Firefox bug 1234813).
* Support for RC4 encryption was deprecated in Firefox 36 and disabled by default in Firefox 44. The one-year grace period has ended, so Firefox 50 removes all support for RC4 (Google Chrome removed support for RC4 in August 2016). From now on, any time Firefox encounters RC4 encryption, it will report an `SSL_ERROR_NO_CYPHER_OVERLAP` error.
### Networking
* When an error has happened during an asynchronous `XMLHttpRequest`, the `XMLHttpRequest.getAllResponseHeaders()` method now returns an empty string (Firefox bug 1286744).
* Instead of returning a `NetworkError`, asynchronous `XMLHttpRequest` that fails for CORS or other network constraints now raises an `error` that can be caught like any other error (Firefox bug 709991).
* `XMLHttpRequest.getResponseHeader()` and `XMLHttpRequest.getAllResponseHeaders()` now also return empty headers by default. This can be controlled via the preference `network.http.keep_empty_response_headers_as_empty_string` (Firefox bug 918721).
* The `only-if-cached` option has been added to `Request.cache` (Firefox bug 1272436).
### DOM
* The `once` option for `EventTarget.addEventListener()` is now supported (Firefox bug 1287706).
* The interface `NodeList` are now iterable and the methods `forEach()`, `values()`, `NodeList.entries()` and `NodeList.keys()` are now available (Firefox bug 1290636).
* The interface `DOMTokenList` are now iterable and the methods `forEach()`, `values()`, `DOMTokenList.entries()` and `DOMTokenList.keys()` are now available (Firefox bug 1290636).
* The methods `Document.createElement()` and `Document.createElementNS()` now have an optional `options` parameter for creating custom elements (Firefox bug 1276579).
### SVG
* The `allowReorder` attribute has been dropped and the behavior it was setting is now the default for SVG `<switch>` elements (Firefox bug 1279690).
* The `defer` keyword for the `preserveAspectRatio` attribute on SVG `<image>` elements has been removed to follow the latest SVG2 specification (Firefox bug 1280425).
### Drag and Drop API
* The `DataTransfer.items` property has been implemented, allowing access to multiple items being dragged and dropped using the HTML Drag and Drop API. To allow this, the `DataTransferItem` and `DataTransferItemList` interfaces are now supported as well (Firefox bug 906420). This is enabled by default.
* The old, obsolete Firefox specific drag and drop API events `dragdrop` and `draggesture` are no longer supported. Be sure to update any code still using them to use the HTML drag and drop API (Firefox bug 1162050.
### Pointer Lock API
* The Pointer Lock API is now unprefixed (Firefox bug 991899).
* Before Firefox 50, `requestPointerLock()` asked for permission using a doorhanger, and pointer lock would not be enabled until the user granted permission. From Firefox 50, pointer lock is like the fullscreen API: it's granted immediately, but a notification is displayed explaining to the user how to exit (Firefox bug 1273351).
### IndexedDB
* A `close` event is now sent to the `IDBDatabase` object when the corresponding database is unexpectedly closed (Firefox bug 1151017).
### Service Workers
* The `WindowClient.navigate()` method has been implemented. This method lets you open a specified URL into a client window which is being controlled by the service worker (Firefox bug 1218148).
### WebGL
* The `EXT_shader_texture_lod` WebGL extension has been implemented (Firefox bug 1111689).
* The texImage methods have been updated for WebGL 2 to implement PBOs (`PIXEL_UNPACK_BUFFER`) (Firefox bug 1280499).
### WebRTC
* Adding a track to a `MediaStream` now generates the `addtrack` event as described in the specification. The event is of type `MediaStreamTrackEvent` and is fired on the stream to which the track was added. You can use either `MediaStream.addEventListener('addtrack', ...)` or the `onaddtrack` property to handle `"addtrack"` events.
* The `MediaStreamTrack` interface now supports the `ended` event and its event handler.
* Firefox now supports the `MediaStreamTrack.readyState` property, which indicates whether the track is live or permanently ended.
* The `MediaStreamTrack` methods `getConstraints()` and `getSettings()` have been implemented; these let you get the most recently applied set of customized property constraints and the actual values of all of the track's constrainable properties, respectively. The accompanying data types have been documented as well.
* The `RTCDataChannel.stream` property has been removed. This was replaced with `RTCDataChannel.id` in Firefox 24, but was supported for backward compatibility. Please be sure to update your code to use the `id` property if you haven't done so yet.
### Web Audio API
* The `PannerNode` interface now supports the 3D Cartesian space properties for the position (`PannerNode.positionX`, `PannerNode.positionY`, and `PannerNode.positionZ`) and directionality (`PannerNode.orientationX`, `PannerNode.orientationY`, `PannerNode.orientationZ`) of an audio source.
* The interface `IIRFilterNode`, which implements a general infinite impulse response (IIR) filter, has been implemented.
* Throttling in background tabs of timers created by `setInterval()` and `setTimeout()` no longer occurs if a Web Audio API `AudioContext` is actively playing sound. This should help prevent issues with timing-sensitive audio playback (such as music players generating individual notes using timers) in the background (Firefox bug 1181073).
### Audio/Video
* The `AlignSetting` enum (representing possible values for `VTTCue.align`) incorrectly previously included the value `"middle"` instead of `"center"`. This has been corrected (Firefox bug 1276130).
* The non-standard and experimental method `HTMLMediaElement.seekToNextFrame()` now seeks to the next frame in the media asynchronously, rather than synchronously, and returns a `Promise` which resolves once the seek is complete.
* The implementation of `HTMLTrackElement` has been corrected to allow `<track>` elements to load resources even if not in a document (Firefox bug 871747).
### Battery API
* The `Navigator.battery` property, which has been deprecated since Firefox 43, is now obsolete and has been removed. Use the `navigator.getBattery()` method instead to get a battery `Promise`, which will resolve when the `BatteryManager` is available for use; the `BatteryManager` is passed into the fulfillment handler for the promise (Firefox bug 12593355).
### Files and directories
* A subset of the File and Directory Entries API has been implemented, to improve compatibility with sites that were previously only compatible with Google Chrome (Firefox bug 1265767).
+ The asynchronous API interfaces have been implemented, with the caveat that only reading of files is supported; for example, the `FileSystemFileEntry.createWriter()` method is a no-op.
+ These interfaces have been implemented:
- `FileSystem`
- `FileSystemEntry` (properties only; the methods have not been implemented)
- `FileSystemFileEntry` (except for `createWriter()`)
- `FileSystemDirectoryEntry` (except for `removeRecursively()`)
- `FileSystemDirectoryReader`
+ `HTMLInputElement.webkitdirectory` as well as the `webkitdirectory` attribute of the `<input>` element have been implemented; this lets you configure a file input to accept directories instead of files (Firefox bug 1258489).
+ `HTMLInputElement.webkitEntries` has been implemented; this returns an array of `FileSystemEntry`-based objects representing the selected items.
+ `File.webkitRelativePath` has been implemented; this contains the path of the file relative to the root of the containing `FileSystemDirectoryEntry` that was among the items in the list returned by `HTMLInputElement.webkitGetEntries()`.
+ See File and Directory Entries API support in Firefox for details about what we do and do not support in this API.
+ These APIs are now enabled by default; some were previously available but only behind a preference (Firefox bug 1288683).
* We've implemented `DataTransferItem.webkitGetAsEntry()` as part of the File and Directory Entries API; this lets you obtain a `FileSystemEntry` representing a dropped file (Firefox bug 1289255). This is enabled by default.
* The `HTMLInputElement.directory` property, part of the Directory Upload API proposal, has been renamed to `allowdirs` (Firefox bug 1288681). This property is hidden behind a preference.
Older versions
--------------
* Firefox 49 for developers
* Firefox 48 for developers
* Firefox 47 for developers
* Firefox 46 for developers
* Firefox 45 for developers
* Firefox 44 for developers
* Firefox 43 for developers
* Firefox 42 for developers
* Firefox 41 for developers
* Firefox 40 for developers
* Firefox 39 for developers
* Firefox 38 for developers
* Firefox 37 for developers
* Firefox 36 for developers
* Firefox 35 for developers
* Firefox 34 for developers
* Firefox 33 for developers
* Firefox 32 for developers
* Firefox 31 for developers
* Firefox 30 for developers
* Firefox 29 for developers
* Firefox 28 for developers
* Firefox 27 for developers
* Firefox 26 for developers
* Firefox 25 for developers
* Firefox 24 for developers
* Firefox 23 for developers
* Firefox 22 for developers
* Firefox 21 for developers
* Firefox 20 for developers
* Firefox 19 for developers |
Firefox 61 for developers - Mozilla | Firefox 61 for developers
=========================
This article provides information about the changes in Firefox 61 that will affect developers. Firefox 61 was released on June 26, 2018.
Changes for web developers
--------------------------
### Developer tools
* The new-look Console UI has been enabled by default for the Browser Console & Browser Toolbox (Firefox bug 1362023/Firefox bug 1347127). The old UI has been removed.
* In the Network Monitor, clicking *Open in New Tab* in a `POST` request's context menu correctly resends the request with the expected `POST` parameters (Firefox bug 1407515).
* CSS variables now autocomplete with color swatches, allowing you to see exactly what color value is stored in each variable (Firefox bug 1451211).
+ In addition, hovering over a CSS variable name brings up a tooltip showing what color value is stored in that variable (Firefox bug 1431949).
* The main toolbox's toolbar has been redesigned. Highlights are better responsiveness for narrow and wide viewports with a new overflow dropdown, cleaned up meatball menu, and sortable tabs to let you move up your most used panels (Firefox bug 1226272).
* The Network Monitor's toolbar now includes a dropdown menu providing easier access to the 'Copy All As HAR' and 'Save All As HAR' commands, as well as an 'Import…' option (Firefox bug 1403530).
* The Network Monitor's details pane now includes a Cache tab, which displays information about previously cached resources (Firefox bug 859051).
* The Network Monitor's main toolbar got redesigned to be more responsive on smaller viewports and visually aligned with the Console.
* The Network Monitor's main toolbar now includes a Throttling dropdown which was only available in the Responsive Design Mode before. It allows you to throttle your network speed to emulate various different network speed conditions (Firefox bug 1349559).
* The Browser Console now hides CSS errors by default for readability and performance reasons (Firefox bug 1452143).
* The Browser Console now includes a command to restart the browser. Use `Ctrl` + `Alt` + `R` (Windows, Linux) or `Cmd` + `Alt` + `R` (Mac) to restart the browser with the same tabs open as before the restart.
* DevTools' web extension APIs `devtools.network.onRequestFinished` (Firefox bug 1311171) and `devtools.network.getHAR` (Firefox bug 1311177) got implemented (enabling extensions like har-export-trigger).
* The Firebug theme got removed since the transition of Firebug users into DevTools is complete (Firefox bug 1378108).
### HTML
*No changes.*
### CSS
* CSS parsing has been parallelized (Firefox bug 1346988).
* Support for `font-variation-settings` and `font-optical-sizing` has been enabled by default (Firefox bug 1447163).
* The `grid-gap`, `grid-row-gap`, and `grid-column-gap` properties have been renamed to `gap`, `row-gap`, and `column-gap`, as they are no longer grid-specific (Firefox bug 1398482). See Box alignment; Gaps between boxes for additional details. The old names have been kept as aliases for web compatibility purposes.
* The `flex-basis` `content` value is now supported (Firefox bug 1105111).
* Percentage values of `column-gap` are now supported in CSS multi-column layout (Firefox bug 1398537).
* The CSS `:host` pseudo-class is now supported; this selects a custom element from inside its shadow DOM (Firefox bug 992245).
* `overflow` now accepts two-value syntax (Firefox bug 1453148).
* Flex items that are sized according to their content are now sized using `max-content`, not `fit-content` (Firefox bug 1282821). See the `width` value definitions for more details of these values.
* `font-weight`, `font-stretch` and `font-style` now support additional values as defined by CSS Fonts level 4 (Firefox bug 1436048):
+ `font-weight` now accepts a floating-point value between 1 and 1000 inclusive.
+ `font-stretch` now accepts percentage values.
+ `font-style` now accepts an angle after the `oblique` keyword.
* The `@font-face` descriptor equivalents of the three properties mentioned in the above entry also support the new syntax listed above, and additionally now support a two-value syntax allowing us to specify a range of descriptor values supported by a font-face (Firefox bug 1436061, Firefox bug 1436048).
### SVG
* The `ping`, `rel`, `referrerPolicy`, `relList`, `hreflang`, `type` and `text` properties have been added to the `<a>` element (`SVGAElement`) to be consistent with the HTML `<a>` element (Firefox bug 1451823).
* The `<textPath>` element (`SVGTextPathElement`) now supports the SVG2 `path` and `side` attributes (Firefox bug 1446617 and Firefox bug 1446650).
* The `SVGGeometryElement` interface is now supported for more elements and not just for the `<path>` element (Firefox bug 1325320).
### JavaScript
* The `String.prototype.trimStart()` and `String.prototype.trimEnd()` methods have been implemented (see Firefox bug 1434007). `trimLeft` and `trimRight` remain as aliases for web compatibility reasons.
### APIs
#### New APIs
* The `PerformanceServerTiming` API has been implemented. It surfaces server-side metrics sent via the `Server-Timing` header (Firefox bug 1423495).
#### DOM
* The `anchors`, `applets`, `embeds`, `forms`, `head`, `images`, `links`, `plugins`, and `scripts` properties have been moved from the `HTMLDocument` interface onto `Document` (Firefox bug 1415588).
* `DOMTokenList.replace()` now returns a boolean value to indicate whether the replacement occurred successfully, rather than void (Firefox bug 1444909).
* The Fetch API's `Request.credentials` property now defaults to `"same-origin"` per the latest revision of the specification (Firefox bug 1394399).
* The `Request.destination` property has been implemented (Firefox bug 1402892).
* The `MutationObserver` option dictionary, `MutationObserverInit`, no longer has `false` as the default value of all of its Boolean properties. Now, only `childList` and `subtree` have default values (of `false` still). The other properties have no default values (Firefox bug 973638).
* The Payment Request API method `PaymentRequest.show()` now supports using a `Promise` to let the client side code provide updated payment details prior to activating the payment interface (Firefox bug 1441709).
#### DOM events
*No changes.*
#### Service workers
The "Forget" button, available in Firefox's customization options, now clears service workers and their caches (Firefox bug 1252998).
#### Web Audio, Media and WebRTC
* The `AudioContext()` constructor now accepts an optional `options` parameter. This lets you configure the preferred latency and/or sample rate for the new context.
* Firefox now throws the correct exceptions when instantiation of an `AudioBuffer` fails.
#### WebVR
* The WebVR API has been enabled by default on macOS (Firefox bug 1244242).
#### Canvas and WebGL
*No changes.*
#### CSSOM
* The `CSSStyleRule.selectorText` property is now fully implemented and no longer read-only (Firefox bug 37468).
* The `MediaList` interface implementation is now a little closer to the specification. It is not all the way there yet; for example, stringifier attributes haven't been implemented yet (Firefox bug 1455807).
### HTTP
* The cookie directive `SameSite` has been implemented. See Set-Cookie and HTTP cookies (Firefox bug 795346).
### Networking
* Firefox 61 and later no longer support using the FTP protocol (that is, URLs with the `"ftp://"` scheme) to load subresources from within HTML content. FTP is still supported as a top-level URL entered directly into the URL bar or loaded as a standalone document (Firefox bug 1404744).
### Security
*No changes.*
### Plugins
*No changes.*
### Other
*No changes.*
Removals from the web platform
------------------------------
### Developer tools
`Cmd`/`Ctrl` + `Shift` + `O` no longer shows/hides the DevTools options panel — use `F1` instead (Firefox bug 1409456).
### HTML
*No changes.*
### CSS
`@-moz-document` has been disabled in content pages (Firefox bug 1422245).
### APIs
* The `File` interface's property `lastModifiedDate` has been removed (Firefox bug 1458883).
* The `Node.setUserData` and `Node.getUserData` methods have been removed from the platform completely (Firefox bug 749981).
* The `Element.createShadowRoot()` method has been removed. Use `Element.attachShadow()` instead (Firefox bug 1453789).
* The `MediaStream` overload of the `URL.createObjectURL()` method has been removed (Firefox bug 1454889).
### SVG
* The deprecated (and never properly implemented) `SVGViewElement``.viewTarget` property has been removed (Firefox bug 1455763).
* The following deprecated properties have been removed from `SVGSVGElement` (Firefox bug 1133172):
+ `pixelUnitToMillimeterX`
+ `pixelUnitToMillimeterY`
+ `screenPixelToMillimeterX`
+ `screenPixelToMillimeterY`
* The non-standard `SVGNumber()` constructor has been removed (Firefox bug 1455940).
### Other
*No changes.*
Changes for add-on and Mozilla developers
-----------------------------------------
### WebExtensions
* Autocomplete popups are now themeable (Firefox bug 1417883).
* `tabs.onUpdated` now has a filter template (Firefox bug 1329507).
* The default document colors can now be overridden, using `browserSettings.overrideDocumentColors` (Firefox bug 1417810).
* tabs.query has been optimized with the implementation of some useful search/filter option parameters (Firefox bug 1445316).
* You can now use `permissions.request` from an `about:addons` preferences page (Firefox bug 1382953).
* You can now force web pages to use system fonts instead of the fonts they specify using the `browserSettings.useDocumentFonts` property (Firefox bug 1400805).
* You can now cause browser search autocomplete suggestions to automatically open in a new tab rather than the current tab using the `browserSettings.openUrlbarResultsInNewTabs` property (Firefox bug 1432645).
* You can control whether the user can close a tab using double-click with the `browserSettings.closeTabsByDoubleClick` property (Firefox bug 1435142).
* The `toolbar`, `toolbar_text`, `toolbar_field`, `toolbar_field_text`, and `toolbar_field_border` theme manifest properties now also apply to the findbar (Firefox bug 1418605).
* In `sidebarAction.getPanel()`, `sidebarAction.getTitle()`, `sidebarAction.setPanel()`, `sidebarAction.setTitle()`, and `sidebarAction.setIcon()`, you can now specify a `windowId` so that the features will be set/got only for a specific window (Firefox bug 1390464).
* `tabs.hide()` and `tabs.show()` are now enabled by default (Firefox bug 1455040).
+ The first time an extension hides a tab, the browser will tell the user that the tab is being hidden, show them how they can access the hidden tab, and give them the option of disabling the extension instead (Firefox bug 1438363).
Older versions
--------------
* Firefox 60 for developers
* Firefox 59 for developers
* Firefox 58 for developers
* Firefox 57 for developers
* Firefox 56 for developers
* Firefox 55 for developers
* Firefox 54 for developers
* Firefox 53 for developers
* Firefox 52 for developers
* Firefox 51 for developers
* Firefox 50 for developers
* Firefox 49 for developers
* Firefox 48 for developers
* Firefox 47 for developers
* Firefox 46 for developers
* Firefox 45 for developers
* Firefox 44 for developers
* Firefox 43 for developers
* Firefox 42 for developers
* Firefox 41 for developers
* Firefox 40 for developers
* Firefox 39 for developers
* Firefox 38 for developers
* Firefox 37 for developers
* Firefox 36 for developers
* Firefox 35 for developers
* Firefox 34 for developers
* Firefox 33 for developers
* Firefox 32 for developers
* Firefox 31 for developers
* Firefox 30 for developers |
Firefox 88 for developers - Mozilla | Firefox 88 for developers
=========================
This article provides information about the changes in Firefox 88 that will affect developers. Firefox 88 was released on April 19, 2021.
**Note:** See also Never too late for Firefox 88 on Mozilla Hacks.
Changes for web developers
--------------------------
### Developer Tools
* The toggle button for switching between raw and formatted response views has been implemented (Firefox bug 1693147). For examples, see Network request details > Response tab.
### HTML
*No changes.*
### CSS
* The `:user-valid` and `:user-invalid` pseudo-classes have been implemented (Firefox bug 1694141).
* The `image/image-set()` functional notation is now enabled (Firefox bug 1698133), and was made available for `content` and `cursor` in Firefox bug 1695402 and Firefox bug 1695403.
* The default `monospace` font for MacOS has been changed to Menlo (Firefox bug 1342741).
* The `collapse` value of `visibility` is now implemented for ruby annotations (Firefox bug 1697529).
* The `alternate` value for `ruby-position` has been implemented, and is the new initial value for the property (Firefox bug 1694748).
* The `outline` CSS property has been updated to follow the outline created by `border-radius`. As part of this work the non-standard `-moz-outline-radius` property has been removed. (Firefox bug 315209 and Firefox bug 1694146.)
#### Removals
* The `:-moz-submit-invalid` pseudo-class has been hidden behind a preference, thereby removing it from web content (Firefox bug 1694129).
* Default styling for the non-standard `:-moz-ui-invalid` and `:-moz-ui-valid` has been removed (Firefox bug 1693969).
### JavaScript
* Added support for RegExp match indices (Firefox bug 1519483).
* `Intl.DisplayNames()` and `Intl.ListFormat()` now have stricter checking that `options` passed to the constructor are objects, and will throw an exception if a string or other primitive is used instead (Firefox bug 1696881).
### HTTP
* FTP has been disabled on all releases (preference `network.ftp.enabled` now defaults to `false`), with the intent of removing it altogether in Firefox 90 (Firefox bug 1691890). Complementing this change, the extension setting `browserSettings.ftpProtocolEnabled` has been made read-only, and web extensions can now register themselves as protocol handlers for FTP (Firefox bug 1626365).
### Security
*No changes.*
### APIs
#### DOM
* Code can now use the new static method `AbortSignal.abort()` to return an `AbortSignal` that is already set as `aborted` (Firefox bug 1698468).
### WebDriver conformance (Marionette)
* Marionette will no longer be enabled unless the `--marionette` command line argument or the `MOZ_MARIONETTE` environment variable is specified. As such the `marionette.enabled` preference is no longer used. With this change the state of `navigator.webdriver` now correctly reflects the enabled state of Marionette (Firefox bug 1593343).
* Fixed a bug where pointer actions other than `down` and `up` inappropriately led to buttons being pressed (Firefox bug 1686361).
* Fixed a race condition in `WebDriver:GetCurrentURL` that could have led the command to return the URL of the previously opened page, or even a hang in Marionette (Firefox bug 1664881).
Changes for add-on developers
-----------------------------
* `url` can now be used to limit the properties for which the `tabs.onUpdated` event is triggered (Firefox bug 1680279).
Older versions
--------------
* Firefox 87 for developers
* Firefox 86 for developers
* Firefox 85 for developers
* Firefox 84 for developers
* Firefox 83 for developers
* Firefox 82 for developers
* Firefox 81 for developers
* Firefox 80 for developers
* Firefox 79 for developers
* Firefox 78 for developers
* Firefox 77 for developers
* Firefox 76 for developers
* Firefox 75 for developers
* Firefox 74 for developers
* Firefox 73 for developers
* Firefox 72 for developers
* Firefox 71 for developers
* Firefox 70 for developers
* Firefox 69 for developers
* Firefox 68 for developers
* Firefox 67 for developers
* Firefox 66 for developers
* Firefox 65 for developers
* Firefox 64 for developers
* Firefox 63 for developers
* Firefox 62 for developers
* Firefox 61 for developers
* Firefox 60 for developers
* Firefox 59 for developers
* Firefox 58 for developers
* Firefox 57 for developers |
Firefox 95 for developers - Mozilla | Firefox 95 for developers
=========================
This article provides information about the changes in Firefox 95 that will affect developers.
Firefox 95 was released on December 7, 2021.
Changes for web developers
--------------------------
### HTML
* The `inputmode` global attribute is now supported on all platforms, instead of just Android.
This provides a hint to browsers about the type of virtual keyboard that would be best suited to editing a particular element (Firefox bug 1205133).
### CSS
* The CSS `cursor` property is now supported on Firefox for Android,
making it easier for Android users with a mouse to determine which elements are clickable (Firefox bug 1672609).
### JavaScript
No notable changes
### APIs
* The `Crypto.randomUUID()` function is now supported. This returns a cryptographically strong 36 character fixed-length UUID (Firefox bug 1723674).
#### Media, WebRTC, and Web Audio
* `SpeechSynthesisEvent.elapsedTime` now returns the elapsed time in seconds rather than milliseconds, matching an update to the specification (see Firefox bug 1732498).
### WebDriver conformance (Marionette)
* The `port` used by Marionette is now written to the `MarionetteActivePort` file in the profile directory. This can be used to easily retrieve the `port`, which before was only possible by parsing the `prefs.js` file of the profile. (Firefox bug 1735162).
* `WebDriver:NewSession` now waits for the initial tab to have completed loading to prevent unexpected unloads of the window proxy. (Firefox bug 1736323).
Changes for add-on developers
-----------------------------
* Added `overrideContentColorScheme` in `browserSettings` to provide the ability to control the preference `layout.css.prefers-color-scheme.content-override` and set pages' preferred color scheme (light or dark) independently of the browser theme (Firefox bug 1733461).
* Added `globalPrivacyControl` in `privacy.network` to provide visibility into whether the user has enabled Global Privacy Control inside the browser. (Firefox bug 1670058).
* Added the `"webRequestFilterResponse.serviceWorkerScript"` API permission. This permission provides access to `webRequest.filterResponseData` for requests originated for service worker scripts. This permission can be provided as an optional permission. See `webRequest.filterResponseData` for more information on using these permissions (Firefox bug 1636629).
Older versions
--------------
* Firefox 94 for developers
* Firefox 93 for developers
* Firefox 92 for developers
* Firefox 91 for developers
* Firefox 90 for developers
* Firefox 89 for developers
* Firefox 88 for developers
* Firefox 87 for developers
* Firefox 86 for developers
* Firefox 85 for developers
* Firefox 84 for developers
* Firefox 83 for developers
* Firefox 82 for developers
* Firefox 81 for developers
* Firefox 80 for developers
* Firefox 79 for developers
* Firefox 78 for developers
* Firefox 77 for developers
* Firefox 76 for developers
* Firefox 75 for developers
* Firefox 74 for developers
* Firefox 73 for developers
* Firefox 72 for developers
* Firefox 71 for developers
* Firefox 70 for developers
* Firefox 69 for developers
* Firefox 68 for developers
* Firefox 67 for developers
* Firefox 66 for developers
* Firefox 65 for developers
* Firefox 64 for developers |
Firefox 37 for developers - Mozilla | Firefox 37 for developers
=========================
Firefox 37 was released on March 31st, 2015. This article lists key changes that are useful not only for web developers, but also Firefox and Gecko developers as well as add-on developers.
Changes for Web developers
--------------------------
### Developer Tools
Highlights:
* Security panel in the Network Monitor
* Animations panel in the Page Inspector
* *Support for running a custom build step in WebIDE*
All devtools bugs fixed between Firefox 36 and Firefox 37.
### CSS
* `display: contents` is now activated by default (Firefox bug 1102374 and Firefox bug 1105369).
* CSS multi-column layout is now working on elements with `display: table-caption` (Firefox bug 1109571).
* Relative positioning (`position: relative`) of table cells has been implemented (Firefox bug 35168).
* The quirks mode behavior of `empty-cells` has been removed: it now defaults to `show` like in standard mode (Firefox bug 1020400).
### HTML
* The value `<a rel="noreferrer">` now also works when the link is opened in new tab (Firefox bug 1031264).
* The `'.'` followed by the extension is now allowed in `<input accept>`: when used, a file selector filters with this given extension to be proposed to the user (Firefox bug 826176).
### JavaScript
* The `Map`, `Set`, `WeakMap` and `WeakSet` constructors now ignore null iterable (Firefox bug 1092538).
* The `Map`, `Set`, `WeakMap` and `WeakSet` constructors now supports monkey-patched `prototype.set` or `prototype.add` (Firefox bug 804279).
* The Non-standard `String.prototype.quote()` method has been removed (Firefox bug 1103181).
* The `RegExp.prototype.flags` property has been implemented (Firefox bug 1108467).
* Several `Array` methods have been implemented for typed arrays as well:
+ The `every()` and `some()` methods (Firefox bug 1116390).
+ The `find()` and `findIndex()` methods (Firefox bug 1078975).
+ The `fill()` method (Firefox bug 1113722).
+ The `indexOf()` and `lastIndexOf()` methods (Firefox bug 1107601).
+ The `join()` method (Firefox bug 1115817).
+ The `reduce()` and `reduceRight()` methods (Firefox bug 1117350).
+ The `reverse()` method (Firefox bug 1111516).
+ The `keys()`, `values()`, and `entries()` methods (Firefox bug 1119217).
* The ES2015 `Proxy` enumerate trap for `for...in` statements is implemented (Firefox bug 783829).
* The `configurable` attribute of the `Function.length` property is now `true` per the ES2015 specification (Firefox bug 911142).
* The development of ParallelJS (PJS) has been discontinued due to the limited future prospects, little attention and code complexity. The experimental implementation that had been enabled only on the Nightly channel, including the `Array.prototype.mapPar`, `filterPar` and `reducePar` methods, has been completely removed.
### Interfaces/APIs/DOM
* The `StereoPannerNode` Web Audio node has been implemented (Firefox bug 1100349).
* The `Promise`-based version of `OfflineAudioContext` is now available (Firefox bug 1087944).
* The experimental, not activated by default, implementation of Service Workers progresses: `ServiceWorkerGlobalScope.update()` has been implemented Firefox bug 1065366.
* The IndexedDB API can now be used in Web workers (Firefox bug 701634).
* Our experimental implementation of WebGL 2.0 is going forward!
+ The `WebGL2RenderingContext.getBufferSubData()` method has been implemented to provide access to Buffer Objects (Firefox bug 1048731).
* In keeping with the evolving WebRTC specification, we have deprecated `RTCIceServer.url` in favor of `RTCIceServer.urls`, which lets you specify more than one URL for a given ICE server.
* Some key names of `KeyboardEvent.key` are changed for conforming the latest DOM Level 3 Events spec. See the tables of `KeyboardEvent.key` values in MDN. The green cells are new values. And purple values are still unstable. Be careful if you use them (meta bug for these changes is Firefox bug 900372).
* The `console` interface is now working on `ServiceWorker` and `SharedWorker`. It was previously available but not working (Firefox bug 1058644).
* The value of `KeyboardEvent.key` was incorrectly being reported as `"RomanCharacters"` when the `英数` (`Eisu`) key was pressed. Now it correctly returns `"Eisu"`.
### MathML
*No change.*
### SVG
* SVG2's `<marker orient="auto-start-reverse">` has been implemented (Firefox bug 1107584).
### Audio/Video
*No change.*
Networking
----------
* WebSockets now supports the `permessage` compression method, if the server does support it (Firefox bug 792831).
Security
--------
* The usage of weak protocols or ciphers, like SSL 3.0 and RC4, are now logged in the console, to warn sites that are using it (Firefox bug 1092835).
* The CSP 1.1 `referrer` directive is now supported (Firefox bug 965727).
Changes for add-on and Mozilla developers
-----------------------------------------
### Add-on SDK
*No change.*
### XUL
*No change.*
Older versions
--------------
* Firefox 36 for developers
* Firefox 35 for developers
* Firefox 34 for developers
* Firefox 33 for developers
* Firefox 32 for developers
* Firefox 31 for developers
* Firefox 30 for developers
* Firefox 29 for developers
* Firefox 28 for developers
* Firefox 27 for developers
* Firefox 26 for developers
* Firefox 25 for developers
* Firefox 24 for developers
* Firefox 23 for developers
* Firefox 22 for developers
* Firefox 21 for developers
* Firefox 20 for developers
* Firefox 19 for developers
* Firefox 18 for developers
* Firefox 17 for developers
* Firefox 16 for developers
* Firefox 15 for developers
* Firefox 14 for developers
* Firefox 13 for developers
* Firefox 12 for developers
* Firefox 11 for developers
* Firefox 10 for developers
* Firefox 9 for developers
* Firefox 8 for developers
* Firefox 7 for developers
* Firefox 6 for developers |
Firefox 107 for developers - Mozilla | Firefox 107 for developers
==========================
This article provides information about the changes in Firefox 107 that will affect developers. Firefox 107 was released on November 15, 2022.
Changes for web developers
--------------------------
### HTML
No notable changes
### MathML
* Deprecated `lquote` and `rquote` attributes of the `<ms>` MathML element for custom opening and closing quotes are now disabled.
This behavior is configured via the `mathml.ms_lquote_rquote_attributes.disabled` preference which is set to `true` by default (Firefox bug 1793387).
### CSS
* The `contain-intrinsic-size` shorthand CSS property can now be applied to specify the size of a UI element that is subject to size containment.
This allows a user agent to determine the size of an element without needing to render its child elements.
The shorthand properties `contain-intrinsic-width` and `contain-intrinsic-height` are also supported, along with the logical properties `contain-intrinsic-block-size` and `contain-intrinsic-inline-size`.
(Firefox bug 1597529).
* Color font is now supported via the font-palette property (Firefox bug 1791558). Support has also been added for the @font-palette-values CSS at-rule and its descriptors font-family, base-palette, and override-colors. Together they help to define the color palette (Firefox bug 1791558).
### JavaScript
No notable changes
### APIs
#### Removals
* The non-standard and deprecated `SVGSVGElement.useCurrentView` property has been removed.
(See Firefox bug 1174097 for more details.)
### WebDriver conformance (WebDriver BiDi, Marionette)
#### WebDriver BiDi
* Added Realm support to `target` argument for `script.evaluate`, `script.callFunction`, and `script.disown` commands (Firefox bug 1779231).
* Added support for JSON serialization of complex objects with container value fields, eg. `WeakMap` and `Uint8Array` (Firefox bug 1770754).
* Added support for the `context` parameter of the `browsingContext.create` command, which allows opening a new tab related to an existing one (Firefox bug 1765619).
* Improved reliability of the `browsingContext.navigate` command when called with the `wait` parameter set to `none` (Firefox bug 1763109).
#### Marionette
* The command `WebDriver:ElementSendKeys` now only sets the caret if the element is not focused yet (Firefox bug 1791736).
* Updated the command `WebDriver:PerformAction` to no longer accept `undefined` as value for various parameters of the `pointerMove` and `wheel` actions (Firefox bug 1781066).
* Updated the Selenium Atoms to match a recent WebDriver specification change (Firefox bug 1771942).
Changes for add-on developers
-----------------------------
### Other
* The `error` property returned when an error occurs in `scripting.executeScript` now represents any value the script throws or rejects with, instead of being just an object with a message property Firefox bug 1740608.
Older versions
--------------
* Firefox 106 for developers
* Firefox 105 for developers
* Firefox 104 for developers
* Firefox 103 for developers
* Firefox 102 for developers
* Firefox 101 for developers
* Firefox 100 for developers
* Firefox 99 for developers
* Firefox 98 for developers
* Firefox 97 for developers
* Firefox 96 for developers
* Firefox 95 for developers
* Firefox 94 for developers
* Firefox 93 for developers
* Firefox 92 for developers
* Firefox 91 for developers
* Firefox 90 for developers
* Firefox 89 for developers
* Firefox 88 for developers
* Firefox 87 for developers
* Firefox 86 for developers
* Firefox 85 for developers
* Firefox 84 for developers
* Firefox 83 for developers
* Firefox 82 for developers
* Firefox 81 for developers
* Firefox 80 for developers
* Firefox 79 for developers
* Firefox 78 for developers
* Firefox 77 for developers
* Firefox 76 for developers |
Firefox 64 for developers - Mozilla | Firefox 64 for developers
=========================
This article provides information about the changes in Firefox 64 that will affect developers. Firefox 64 was released on December 11, 2018.
Changes for web developers
--------------------------
### Developer tools
* The Accessibility info-bar has been enhanced to include information about the color contrast ratio of text or images on the page (Firefox bug 1473037).
* Responsive Design Mode device selection is now saved between sessions (Firefox bug 1248619).
* Resources that are potentially affected by Tracking Protection are now indicated in the Network Monitor (Firefox bug 1333994).
* The Web Console got improvements around entering and evaluating code:
+ Autocomplete for Console expressions is now case-insensitive (Firefox bug 672733).
+ You can now step through the Console expression history with bash-like reverse search (Firefox bug 1024913).
+ Evaluated code in the Console is now syntax-highlighted in both the input and output (Firefox bug 1463669).
* Stepping in the JavaScript Debugger also had some improvements:
+ Stepping out of a function in the Debugger now skips the return value (Firefox bug 923975).
#### Removals
* The Developer Tools GCLI has been removed (Firefox bug 1429421).
### HTML
*No changes.*
### CSS
* CSS Scrollbars spec functionality has been enabled by default (Firefox bug 1492012).
* Interaction Media Features implemented, including `pointer:coarse` (Firefox bug 1035774). For `any-pointer` and `any-hover` implementation, see Firefox bug 1483111.
* The `prefers-reduced-motion` media feature is now supported in Firefox for Android (Firefox bug 1478505).
* CSS `<gradient>` values now support multi-position color stop syntax, e.g. `yellow 25%, yellow 50%` can now be written `yellow 25% 50%` (Firefox bug 1352643).
* The `text-transform` property now accepts the `full-size-kana` value (Firefox bug 1498148).
* Support added for `-webkit-appearance` to alleviate associated web compat issues (Firefox bug 1368555).
* Closely associated with the above update, we've also removed most of the Firefox-specific `-moz-appearance` values (Firefox bug 1496720).
* `display`: `list-item` is now supported on `<legend>` elements (Firefox bug 1486602).
* SVG `path()`s, as usable in `offset-path`, are now animatable (Firefox bug 1486094).
* If a selector chain or group includes a `-webkit-`prefixed pseudo-element, that pseudo-element no longer invalidates it (see Firefox bug 1424106 for the details, and Firefox bug 1486325 for enabling this feature).
#### Removals
* The non-standard `-moz-box` and `-moz-inline-box` `display` values have been hidden from web content (Firefox bug 1496961).
* The non-standard `::-moz-tree` pseudo-element has been hidden from web content (Firefox bug 1496961).
* The `layout.css.filters.enabled` preference has been removed; CSS filters can no longer be disabled (Firefox bug 1408841).
* A previous change — to swap the values of the 2-value `overflow` syntax so block is specified first and inline second (Firefox bug 1481866) — has been reverted (Firefox bug 1492567). See Bug 1481866 comment 14 for why.
### SVG
*No changes.*
### JavaScript
* The TC39 Well-formed JSON.stringify proposal has been implemented, to prevent `JSON.stringify` from returning ill-formed Unicode strings (Firefox bug 1469021).
* Proxied functions can now be passed to `Function.prototype.toString``.call()` (Firefox bug 1440468).
* In the `WebAssembly.Global()` constructor, if no value is specified a typed 0 value is used. This is specified by the `DefaultValue` algorithm (Firefox bug 1490286).
### APIs
#### DOM
* A number of changes related to the Fullscreen API have been implemented:
+ The API has been unprefixed (Firefox bug 1269276).
+ The `Element.requestFullscreen()` and `Document.exitFullscreen()` methods both now return a `Promise`, which is resolved when the mode change is complete (Firefox bug 1188256 and Firefox bug 1491212).
+ Previously, `fullscreenchange` and `fullscreenerror` events were dispatched to the `Document` first, then the `Element`. This has been reversed so that the element gets the event first. This matches the latest specification as well as the behavior of Google Chrome (Firefox bug 1375319).
* The WebVR API (1.1) is now re-enabled in macOS (Firefox bug 1476091).
* `Window.screenLeft` and `Window.screenTop` have been implemented, as aliases of `Window.screenX` and `Window.screenY` (Firefox bug 1498860).
* The `XMLHttpRequest.getAllResponseHeaders()` method now returns header names all in lowercase, as per spec (Firefox bug 1398718).
* The legacy `HTMLAllCollection` interface has been updated as per recent spec updates (Firefox bug 1398354).
* `Navigator.buildID` now returns a fixed timestamp as a privacy measure (Firefox bug 583181).
* The following `Document.execCommand()` UI feature commands have been disabled by default (Firefox bug 1490641:
+ `enableObjectResizing`
+ `enableInlineTableEditing`
+ `enableAbsolutePositionEditor`
#### Service workers
* The `ServiceWorkerContainer.startMessages()` method has been implemented (Firefox bug 1263734).
#### Media, Web Audio, and WebRTC
* The `PannerNode.refDistance`, `PannerNode.maxDistance`, `PannerNode.rolloffFactor`, and `PannerNode.coneOuterGain` properties now correctly throw exceptions when set to values outside their accepted ranges (Firefox bug 1487963).
* `RTCRtpEncodingParameters` settings changed via `RTCRtpSender.setParameters()` used to not update if the changes were made during a call. They will now update live, without renegotiation (Firefox bug 1253499).
* `RTCIceCandidateStats.relayProtocol` has been implemented — this is the standardized version of `RTCIceCandidateStats.mozLocalTransport`, which has now been deprecated (Firefox bug 1435789).
* Automatic Gain Control (AGC) is now enabled by default; this can be changed using the preference `media.getusermedia.agc_enabled` (Firefox bug 1496714).
#### Removals
* The `Window.event` property, added in Firefox 63 to aid with web compat issues, has been put behind a pref (`dom.window.event.enabled`) and disabled by default in release versions for now due to other issues that have been uncovered (Firefox bug 1493869). Note that this was actually done late in the Firefox 63 release cycle, but we are mentioning it here just in case.
* The `LocalMediaStream` interface and its `stop()` method have been removed (Firefox bug 1258143). This method is no longer available with the deprecation of `LocalMediaStream`. See the Stopping a video stream section to learn how to stop an entire stream.
* The `AudioStreamTrack` and `VideoStreamTrack` interfaces have been removed, as both have been deprecated for some time (Firefox bug 1377146). Their functionality has been merged into `MediaStreamTrack`; tracks are now identified by the value of their `kind` property, such as `audio` or `video`.
### Security
* The Symantec CA Distrust plan has been implemented (see Firefox bug 1409257; see also the Mozilla's Plan for Symantec Roots discussion for more details).
* `Referrer-Policy` can now be used to govern resources fetched via stylesheets (Firefox bug 1330487) — see Integration with CSS for more information.
### Plugins
*No changes.*
### WebDriver conformance (Marionette)
#### API changes
* Deprecated command end-points without the `Marionette:`, `L10n:`, or `Addon:` prefix (including `singeTap`) have been removed (Firefox bug 1504478, Firefox bug 1504940).
#### Bug fixes
* Synthesized `Shift` key events by using `WebDriver:PerformActions` didn't result in capitalized letters (Firefox bug 1405370).
* `WebDriver:Navigate` could cause an infinite hang if the tab's underlying content process is changed multiple times during that navigation (Firefox bug 1504807).
* To improve the performance, and to reduce the memory footprint of Firefox the default page to be loaded for a new tab or window is no longer `about:newtab` but `about:blank` (Firefox bug 1506643).
* The content blocking introduction panel, which was shown on various web pages and caused element interactions to fail is disabled by default now (Firefox bug 1488826).
Changes for add-on developers
-----------------------------
### API changes
#### Menus
* A new API, ``menus.overrideContext()``, can be called from the `contextmenu` DOM event to set a custom context menu in extension pages. This API allows extensions to hide all default Firefox menu items in favor of providing a custom context menu UI. This context menu can consist of multiple top-level menu items from the extension, and may optionally include tab or bookmark context menu items from other extensions. See this blog post for more details.
+ ``menus.overrideContext()`` was implemented in (Firefox bug 1280347).
+ The `showDefaults: false` option, which can be used to hide the default context menu options, was implemented in (Firefox bug 1367160).
+ `documentURLPatterns` can now be used to match a `moz-extension://` document URL, even if ``menus.overrideContext()`` is used. This way, it can reliably be used to restrict custom menu items to certain documents (Firefox bug 1498896).
* You can now restrict where context menus can appear in an add-on using the new `viewTypes` property in `menus.create()` and `menus.update()` (Firefox bug 1416839).
* `menus.update()` can now be used to update the icon of an existing menu item (Firefox bug 1414566).
* Extensions can now detect which mouse button was used when a menu item was clicked — this can be found using the new `button` property of `menus.OnClickData` (Firefox bug 1469148).
#### Windows
* The `windows.create()` method now has a new option available — `cookieStoreId` — which specifies the `CookieStoreId` to use for all tabs that were created when the window is opened (Firefox bug 1393570).
#### Privacy
* The `privacy.websites` `cookieConfig` property is an object that can accept a `behavior` property — this property can now take a new value, `reject_trackers`, which instructs the extension to reject tracking cookies (Firefox bug 1493057).
#### devtools.panels API
* The `devtools.panels.elements` `Sidebar.setPage()` method is now supported (Firefox bug 1398734).
### Manifest changes
* The new `pinned` property of the `page_action` manifest key enables extensions to control whether their page actions should be pinned to the location bar on install or not (Firefox bug 1494135).
* In native manifests on Windows, the 32-bit registry view (Wow6432Node) will be checked first for registry keys, followed by the "native" registry view; you should use whichever is appropriate for your application (Firefox bug 1494709).
* The `chrome_settings_overrides` field's `search_provider` object can now include new properties — `suggest_url` and `suggest_url_post_params` (Firefox bug 1486819), and `search_url_post_params`.
See also
--------
* Hacks release post: Firefox 64 Released
Older versions
--------------
* Firefox 63 for developers
* Firefox 62 for developers
* Firefox 61 for developers
* Firefox 60 for developers
* Firefox 59 for developers
* Firefox 58 for developers
* Firefox 57 for developers
* Firefox 56 for developers
* Firefox 55 for developers
* Firefox 54 for developers
* Firefox 53 for developers
* Firefox 52 for developers
* Firefox 51 for developers
* Firefox 50 for developers
* Firefox 49 for developers
* Firefox 48 for developers
* Firefox 47 for developers
* Firefox 46 for developers
* Firefox 45 for developers
* Firefox 44 for developers
* Firefox 43 for developers
* Firefox 42 for developers
* Firefox 41 for developers
* Firefox 40 for developers
* Firefox 39 for developers
* Firefox 38 for developers
* Firefox 37 for developers
* Firefox 36 for developers
* Firefox 35 for developers
* Firefox 34 for developers
* Firefox 33 for developers |
Firefox 55 for developers - Mozilla | Firefox 55 for developers
=========================
Firefox 55 was released on August 8, 2017. This article lists key changes that are useful for web developers.
Changes for Web developers
--------------------------
### Developer Tools
* Added filtering of network requests by column values and other properties (Firefox bug 1041895, Firefox bug 1354508, Firefox bug 1354507) and by using regular expressions (Firefox bug 1354495).
* Made it possible to show and hide columns within the Network Monitor (Firefox bug 862855).
* Added remote IP (Firefox bug 1344523), protocol (Firefox bug 1345489), scheme (Firefox bug 1356867), cookies and set cookies columns (Firefox bug 1356869) to Network Monitor.
* The `SourceMap` HTTP header is now supported (prior versions supported the deprecated `X-SourceMap` header, see Firefox bug 1346936).
### HTML
* Elements on which `contenteditable` has been set to `true` now use `<div>` elements to separate different lines of text, to give Firefox parity with other modern browsers (Firefox bug 1297414). See Differences in markup generation for more details.
* Enable `dom.forms.datetime` by default on Nightly (Firefox bug 1366188).
### CSS
* Exposed the `transform-box` property by default (Firefox bug 1208550).
* Implemented the `frames()` timing function (Firefox bug 1248340).
* Implemented the `text-justify` property (Firefox bug 1343512, Firefox bug 276079).
* [css-grid] `fit-content` unexpectedly reserves space for full clamp size in `repeat()` (Firefox bug 1359060).
* The `float` / `clear` logical values — `inline-start` and `inline-end` — which were previously implemented but preffed off in release channels, are now available in all channels by default (Firefox bug 1253919).
* The `layout.css.variables.enabled` preference has been removed completely meaning that the CSS variables feature is enabled all the time and can no longer be disabled (Firefox bug 1312328).
* Implemented the proprietary `-moz-context-properties` property (Firefox bug 1058040).
* Zero (0) angle value without degree unit is not correctly interpreted in `gradient/linear-gradient()` (Firefox bug 1363292).
* The `::cue` pseudo-element is now supported; it matches on text cues presented within a media element (Firefox bug 1318542).
### SVG
* The `<radialGradient>` `fr` attribute has been implemented (Firefox bug 1240275).
### JavaScript
* The `SharedArrayBuffer` and `Atomics` objects are now enabled by default. See A Taste of JavaScript's New Parallel Primitives for an introduction to JavaScript Shared Memory and Atomics.
* The rest operator (`...`) is now supported in object destructuring and the spread operator (`...`) now works in object literals (Stage 3 ECMAScript proposal: Object Rest/Spread Properties, Firefox bug 1339395).
* Async generator methods are now supported (Firefox bug 1353693).
* The `String.prototype.toLocaleLowerCase()` and `String.prototype.toLocaleUpperCase()` methods now support an optional `locale` parameter to specify a language tag for locale-specific case mappings (Firefox bug 1318403).
* The `Intl.Collator` object now supports the `caseFirst` option (Firefox bug 866473).
* The Intl API now uses the browser's default locale instead of the operating system's default locale when no locale setting is provided (Firefox bug 1346674).
* Template call sites objects are now canonicalized per realm, based upon their list of raw strings (Firefox bug 1108941).
* `TypedArray` constructors (like `Int8Array`, `Float32Array`, etc.) have been updated to ES2017. They now use the `ToIndex` operation and allow constructors without arguments, which return zero-length typed arrays (Firefox bug 1317383).
### APIs
#### New APIs
* The Collaborative Scheduling of Background Tasks API (also known as the **Background Tasks API** or the `requestIdleCallback` API) is now enabled by default after being available behind a preference since Firefox 53. This API lets you schedule tasks to be executed when the browser determines that there's free time available before the next repaint occurs, so that your code can make use of that time without causing visible performance lag (Firefox bug 1314959).
* The WebVR 1.1 API is now turned on by default on Windows (and is available on macOS in Nightly). This API exposes virtual reality devices — for example head-mounted displays like the Oculus Rift or HTC Vive — to web apps, enabling developers to translate position and movement information from the display into movement around a 3D scene, and present content into such displays.
* The Intersection Observer API — which provides a way to asynchronously observe changes in the intersection of a target element with an ancestor element or with a top-level document's viewport — has been added (Firefox bug 1321865).
#### DOM
* The `Window` properties `scrollX` and `scrollY` (as well as their aliases `pageXOffset` and `pageYOffset` have been updated to be subpixel precise. Instead of returning an integer, these now return a floating-point value which more accurately describes the scroll position on subpixel-precise displays (Firefox bug 1151421). If need be, you can use `Math.round()` to convert them into integers.
* `MediaQueryList` (and other related features) have been updated to match the latest spec. See Firefox bug 1354441, and also see `MediaQueryList` and `MediaQueryListEvent`.
* Methods of the `DOMTokenList` that modify the list value now automatically trim whitespace and remove duplicate tokens (Firefox bug 869788, also see Trimming of whitespace and removal of duplicates).
* The `HTMLInputElement`'s `maxLength` property can now be dynamically altered with JavaScript after the equivalent HTML has been created (Firefox bug 1352799).
* The `URL()` constructor can no longer accept a `DOMString` as its base (2nd parameter) — it only accepts a `USVString`. It can still use an existing `URL` object for the base, which stringifies itself to the object's `href` attribute (Firefox bug 1368950).
#### DOM events
* The event types supported by the `Document.createEvent()` method have been updated as per the latest DOM spec (Firefox bug 1251198).
* The `MessageEvent.origin` property value is now of type `USVString`, not `DOMString`, and the `MessageEvent.source` property now takes a `MessageEventSource` value (which can be a WindowProxy, `MessagePort`, or `ServiceWorker` object) (Firefox bug 1311324).
* The pinch-to-zoom gesture has now been mapped to the `wheel` event plus the + `Ctrl` key. This mapping was implemented to allow developers to implement simple zooming functionality using the pinch-to-zoom gesture on mobile screens/trackpads (mousewheel + `Ctrl` commonly zooms) (Firefox bug 1052253).
#### Selection API
* The Selection API has been updated so that it has parity with other browsers in terms of how editing hosts are given focus when the selection moves inside them (Firefox bug 1318312). See Behavior of Selection API in terms of editing host focus changes for more details.
* The `Selection` API has been updated to match some recent spec changes (Firefox bug 1359371):
+ The `collapse()` and `extend()` methods' `offset` parameter is now optional.
+ The `collapse()` method's `node` parameter is now nullable.
+ The `containsNode()` method's `partialContainment` parameter is now optional.
+ The `deleteFromDocument()` method has been added.
* Also in the `Selection` API, `Selection.empty()` and `Selection.setPosition()` have been added as aliases of `Selection.removeAllRanges()` and `Selection.collapse()`, for web compat and WebKit/Blink parity reasons (Firefox bug 1359387).
* The `StorageManager.persist()` and `StorageManager.persisted()` methods of the Storage API have been implemented and exposed to `Window` contexts (Firefox bug 1286717).
#### Workers
* Workers and shared workers can now be created with an identifying `name` property. See the `Worker()` and `SharedWorker()` constructors, and the `DedicatedWorkerGlobalScope` and `SharedWorkerGlobalScope` interfaces. (Firefox bug 1364297).
* `setTimeout()` and `setInterval()` are now subject to minimum interval throttling for tracking scripts in background tabs — see Throttling of tracking timeout scripts (Firefox bug 1355311).
#### Service Workers/Push
* Messages sent to service worker contexts (e.g. as the event object of `onmessage` are now represented by `MessageEvent` objects, for consistency with other web messaging features.
* The `PushManager.subscribe()` method now accepts `ArrayBuffer`s and Base64-encoded strings as `applicationServerKey` values (Firefox bug 1337348).
#### Web Audio API
* A non-standard constructor (which accepted a string enum value indicating the purpose for which the context would be used) for `AudioContext` interface was causing errors to be thrown when the `options` parameter was provided. We have removed the non-standard constructor. However, please note that the `options` parameter is not yet supported in Firefox and is currently ignored (Firefox bug 1361475).
#### WebRTC
* `getUserMedia()` now provides a stereo audio stream by default if the source device provides stereo sound; support to specifically request mono input will come in Firefox 56. This only works on desktop at this time; mobile Firefox does not currently support stereo audio input sources (Firefox bug 971528).
* The `getUserMedia()` media capabilities, constraints, and settings `autoGainControl` and `noiseSuppression` now match the spec; formerly they were `moz`-prefixed (Firefox bug 1366415).
* When called with an empty constraints set, `getUserMedia()` was incorrectly returning `NotSupportedError` instead of `TypeError`. This has been fixed (Firefox bug 1349480).
* The following new WebRTC statistics are available: `framesEncoded`, `pliCount`, `nackCount`, and `firCount` (Firefox bug 1348657).
* The `RTCInboundRTPStreamStats` dictionary field formerly called `mozRtt` has been renamed to `roundTripTime` to match the specification; in addition, its behavior has been adjusted to match the standard: it contains a double-precision floating point value which estimates the round-trip time based on the RTCP timestamps in the RTCP Receiver Report, measured in seconds (following the algorithm described in RFC 3550, section 6.4.1). (Firefox bug 1344970). However, please be aware that *this property is moving* to a different dictionary (`RTCRemoteInboundRTPStreamStats`) soon (Firefox bug 1380555).
* The `RTCRTPStreamStats` dictionary now includes the fields `firCount`, `pliCount`, and `nackCount`. These return low-level information that can be used to determine how reliable the connection is (Firefox bug 1348657).
* The `RTCOutboundRTPStreamStats` dictionary now includes the field `framesEncoded`, which reports the number of frames that have been successfully encoded for the stream; with this information, you can compute the frame rate (Firefox bug 1348657).
* On Android, there's now a pref to turn on hardware video encoding to improve video call performance and save on battery. To be enabled by default in Firefox 56 (Firefox bug 1265755).
#### Encrypted Media Extensions API
* Firefox currently allows Encrypted Media Extensions to be used in insecure contexts, despite this not being allowed in the specification. This will be changed in the near future, and starting in Firefox 55, deprecation warnings are output to the web console when this is done. (Firefox bug 1361000).
* Firefox currently doesn't require that at least one `MediaKeySystemCapabilities` object be included in the `suggestedConfigurations` parameter passed into `Navigator.requestMediaKeySystemAccess()`, which the specification does mandate. Starting in Firefox 55, a warning is output to the web console when any audio or video configuration is specified without specifying supported codecs. Soon, failure to include a valid configuration for one or more of audio and video will throw an exception Firefox bug 1368683).
#### WebGL
* The `WEBGL_compressed_texture_s3tc_srgb` extension is now available to WebGL and WebGL2 contexts (Firefox bug 1325113).
### Security
* The `Geolocation` API is now available only to secure contexts (Firefox bug 1072859).
* The `Storage API` is now available only to secure contexts (Firefox bug 1268804).
* The loading of mixed content is now allowed on localhost (Firefox bug 903966).
* Loading of remote JAR files has been disabled again (Firefox bug 1329336).
### Plugins
* Flash content is now "click-to-activate" (Firefox bug 1317856). This was immediately put into effect for all users of Nightly, and 50% of beta users. For Firefox 55 release version, the plan is to activate this for 5% of users 2 weeks after release, 25% of users 4 weeks after release, and 100% of users 6 weeks after release (Firefox bug 1365714).
* Flash and other plugins can no longer be loaded from any URL scheme except for `http://` and `https://` (Firefox bug 1335475).
### Other
* Firefox on Linux can now be made to run in headless mode using the `-headless` flag (see Firefox bug 1356681).
Removals from the web platform
------------------------------
### HTML
* The `xml:base` attribute can no longer be used to set the base URL for paths appearing in the `style` attribute, for example —
`<div xml:base="https://example.com/" style="background:url(picture.jpg)"></div>` (Firefox bug 1350521).
* The `<style>` element's `scoped` attribute has been hidden behind a pref (`layout.css.scoped-style.enabled`) in content documents in Firefox 55+, as no other browsers support it.
* Support for the obscure `MSThemeCompatible` value of the `<meta>` element's `http-equiv` attribute has been removed from Gecko. No other modern browsers support it, and it was causing compatibility problems (Firefox bug 966240).
### CSS
* The proprietary `:-moz-bound-element` pseudo-class has been removed (Firefox bug 1350147).
* The proprietary `-moz-anchor-decoration` value of `text-decoration-line` has been removed (Firefox bug 1355734).
### APIs
* The `UIEvent.isChar` property has never been supported by any browser but Firefox, and it has never been fully implemented except on macOS. For that reason, it was removed in Firefox 55 to align with other browsers.
* The proprietary Firefox OS Device Storage API has been removed from the platform (Firefox bug 1299500).
* The `aShowDialog` parameter of the non-standard `Window.find()` method (which could be specified to open up a "Find" dialog in the browser) has been removed (Firefox bug 1348409).
* The `HTMLFormElement.requestAutoComplete()` method has been removed (see `HTMLFormElement`) (Firefox bug 1270740).
* The non-standard, Mozilla-specific, WebRTC offer options `mozDontOfferDataChannel` and `mozBundleOnly` have been removed from the `RTCOfferOptions` dictionary and are no longer supported by `RTCPeerConnection.createOffer()` (Firefox bug 1196974).
* Support for the proprietary Firefox OS `Audio Channels API` has been removed from `HTMLMediaElement` and `AudioContext` (Firefox bug 1358061).
### SVG
* The `SVGZoomEvent` and `SVGZoomEvents` interfaces have been removed from the SVG2 spec and Gecko, along with the `onzoom <svg>` attribute (Firefox bug 1314388).
Changes for add-on and Mozilla developers
-----------------------------------------
### WebExtensions
* contextMenus.create()'s command property enables you to open browser action popups, page action popups, and sidebars from the context menu.
* proxy API
* chrome\_settings\_overrides key enables you to override the browser's homepage.
* browser\_style property enables you to have browser-like styling for browser action popups, sidebars, and options pages.
* permissions API
Older versions
--------------
* Firefox 54 for developers
* Firefox 53 for developers
* Firefox 52 for developers
* Firefox 51 for developers
* Firefox 50 for developers
* Firefox 49 for developers
* Firefox 48 for developers
* Firefox 47 for developers
* Firefox 46 for developers
* Firefox 45 for developers
* Firefox 44 for developers
* Firefox 43 for developers
* Firefox 42 for developers
* Firefox 41 for developers
* Firefox 40 for developers
* Firefox 39 for developers
* Firefox 38 for developers
* Firefox 37 for developers
* Firefox 36 for developers
* Firefox 35 for developers
* Firefox 34 for developers
* Firefox 33 for developers
* Firefox 32 for developers
* Firefox 31 for developers
* Firefox 30 for developers
* Firefox 29 for developers
* Firefox 28 for developers
* Firefox 27 for developers
* Firefox 26 for developers
* Firefox 25 for developers
* Firefox 24 for developers |
Firefox 49 for developers - Mozilla | Firefox 49 for developers
=========================
To test the latest developer features of Firefox, install Firefox Developer Edition Firefox 49 was released on September 20, 2016. This article lists key changes that are useful not only for web developers, but also Firefox and Gecko developers as well as add-on developers.
Changes for Web developers
--------------------------
### Developer Tools
* JavaScript errors logged into the console now provide a [Learn more] link for additional debugging help (Firefox bug 1179876).
* CSS autocomplete: show more suggestions in autocomplete popup (Firefox bug 1260419).
* The Animation Inspector now exposes animation performance information in DevTools (Firefox bug 1254408).
* The Inspector's context menu has been reorganized to be cleaner and easier to use (Firefox bug 1211613).
* The Inspector now supports `#RRGGBBAA` and `#RGBA` syntax for color values (Firefox bug 1271191).
* The developer tools no longer display self-closing tags (such as `<br>` and `<img>` as if they have a closing tag on HTML pages; the behavior is unchanged for XHTML pages (Firefox bug 820926).
* Accessibility improvements!
+ The toolbox does a better job of ensuring that keyboard focus is more visible (Firefox bug 1242851).
+ Accessibility labels have been added to unlabeled controls (Firefox bug 1242715).
+ Added proper tree view semantics and keyboard navigation to the Inspector's markup view (Firefox bug 1242694).
* The Network Monitor now shows a Cause column, which provides an indication of what caused each particular network request (Firefox bug 1134073).
* In the *about:debugging* Add-ons page, the Reload button is only enabled for temporary add-ons. It will be disabled for all other add-ons (Firefox bug 1273184).
* In the *about:debugging* Workers page, a warning message will be displayed in the Service Workers section if service workers are incompatible with the current browser configuration (Firefox bug 1266415).
* *about:debugging* now has a new Tabs page available, which provides a complete list of all the debuggable tabs open in the current Firefox instance (Firefox bug 1266128).
* The *Disable Cache* option in the Toolbox Advanced settings has been renamed to Disable HTTP Cache, to make it clearer that this affects the HTTP cache, and not Service Workers/the Cache API (bug(1253018)).
* The Storage Inspector now allows IndexedDB databases to be deleted via their own context menus (Firefox bug 1205123), and will display warning messages if the IndexedDB cannot be deleted for some reason (if there are still active connections, for example) (Firefox bug 1268460).
### HTML
* Added support for the `<details>` and `<summary>` elements (Firefox bug 1226455).
* The `pattern` attribute of the `<input>` element now uses the `'u'` parameter in the underlying JavaScript `RegExp` (Firefox bug 1227906).
* To match a spec change, an invalid value of the `kind` attribute of the `<track>` element is now treated like `"metadata"` instead of `"subtitles"` (Firefox bug 1269712).
* The `<iframe>` element's `sandbox` attribute now supports the `'allow-popups-to-escape-sandbox'` and `'allow-modals'` values (Firefox bug 1190641).
* Support for microdata attributes and the Microdata API have been removed (Firefox bug 909633).
* The `referrerpolicy` attribute on the `<a>` element now supports the `'no-referrer-when-downgrade`' and `'origin-when-cross-origin'` (Firefox bug 1178337).
* The `form` content attribute of the `<label>` element has been removed. The `HTMLLabelElement.form` property still exists, but now returns the form with which the label's control is associated, if there is a control (and if that control is associated with a form) (Firefox bug 1268852).
### CSS
* Added `background-position-x` and `background-position-y`, which allow separately specifying the horizontal and vertical offsets at which to draw a background image; these are components of `background-position` (Firefox bug 550426).
* Added support for the `round` and `space` keywords to `background-repeat` (Firefox bug 548372).
* On `background-clip`, the keyword `text` is now activated by default (Firefox bug 1264905).
* Added support for specifying colors with an alpha channel using 4- and 8-digit CSS hex color values (#RRGGBBAA and #RGBA) (Firefox bug 567283).
* The pseudo-class `:dir` has been unprefixed (Firefox bug 859301).
* In our experimental implementation (not yet activated by default) of `clip-path`, we can now interpolate between `<basic-shape>` values (Firefox bug 1110460).
* Added the `q` length unit (Firefox bug 1274526).
* The property `text-align-last` has been unprefixed (Firefox bug 1039541).
* Added support for `overflow-wrap`, replacing `word-wrap` that is still supported as an alternative name (Firefox bug 955857).
* Our experimental CSS Grids implementation has been improved:
+ Implemented `<percentage>` for the `grid-gap`, `grid-row-gap`, and `grid-column-gap` properties (Firefox bug 1266268).
+ Implemented grid layout support for `align`, `justify-self``:baseline` and `last-baseline` (aka "baseline self-alignment") (Firefox bug 1221525).
+ Implemented grid item baseline content alignment (Firefox bug 1256429).
* Our experimental CSS Masks implementation has been improved:
+ The `mask-origin` property now uses `border-box` instead of `padding-box` as initial value, to match the spec (Firefox bug 1258286).
+ The `mask-repeat` property now supports the `space` and `round` values (Firefox bug 1258626).
+ Fixed an issue preventing the `mask-position` attribute from being animated (Firefox bug 1273804).
* The preference controlling `text-emphasis` has been removed, so support for this property can no longer be disabled (Firefox bug 1229609).
### JavaScript
* The ES2015 `getPrototypeOf()` and `setPrototypeOf()` `Proxy` traps have been implemented (Firefox bug 888969).
* The ES2015 `RegExp.prototype[@@match]()`, `RegExp.prototype[@@replace]()`, `RegExp.prototype[@@search]()`, and `RegExp.prototype[@@split]()` methods, and `RegExp[@@species]` getter have been implemented (Firefox bug 887016).
* The deprecated, non-standard `flags` argument of `String.prototype.``match`/`search`/`replace` has been removed (Firefox bug 1108382).
* The behavior of the `Date.parse()` method when parsing 2-digit years has been changed to be more interoperable with the Google Chrome browser (Firefox bug 1265136).
### Interfaces/APIs/DOM
#### DOM & HTML DOM
* The method `DOMTokenList.supports()` has been added (Firefox bug 1257849).
* The `DOMTokenList.replace()` method has been added (Firefox bug 1224186).
* Leading `'?'` characters are now ignored in the parameter of the `URLSearchParams()` constructor (Firefox bug 1268361).
* The value returned by `URL.origin`, `HTMLAnchorElement.origin`, and `HTMLAreaElement.origin` for URL using the `blob:` scheme is no longer incorrectly `null` but is instead the origin of the URL formed by removing the leading `blob:` (Firefox bug 1270451).
* In prerendering mode, the `Document.visibilityState` property now returns `'prerender'` (Firefox bug 1069772).
* The `isSecureContext` property has been implemented (Firefox bug 1162772).
* The DOM4 `Element.before`, `Element.after`, `Element.replaceWith`, `Element.append` and `Element.prepend` methods have been implemented (Firefox bug 911477).
* The `TouchList.identifiedTouch()` method has been removed (Firefox bug 1188539).
* By default, the `scrollbars` `Window` feature is enabled when calling `Window.open()`. In the past, while it was strongly recommended to enable it, it wasn't the default (Firefox bug 1257887).
* Added the *experimental* and *non-standard* `HTMLMediaElement.seekToNextFrame()` method, which allows seeking frame-by-frame through video content (Firefox bug 1235301). While you're encouraged to experiment with this method to help us understand how useful it is, *do not use it in production code!*
* The `HTMLLabelElement.form` property now returns the form with which the label's control is associated, if there is a control (and if that control is associated with a form). Previously, labels were directly associated with forms using this property (Firefox bug 1268852).
* Support for the third parameter of `EventTarget.addEventListener()`, either a `Boolean` or an `EventListenerOptions` has been added (Firefox bug 1266164 and Firefox bug 1266066).
* The audio volume related values for `KeyboardEvent.key` have been renamed. `"VolumeDown"` is now `"AudioVolumeDown"`, `"VolumeUp"` is now `"AudioVolumeUp"`, and `"VolumeMute"` is now `"AudioVolumeMute".` This brings Firefox into alignment with the latest draft of the UI Events specification (Firefox bug 1272578). See Code values for keyboard events for a full list of available key codes.
* The keys previously referred to as `"MozHomeScreen"`, `"MozCameraFocusAdjust"`, and `"MozPhoneCall"` now have official names in the UI Events specification: `"GoHome"`, `"CameraFocus"`, and `"Call"`. Firefox 49 has been updated to use the new names (Firefox bug 1272599). See Code values for keyboard events for a full list of available key codes.
* The key values `"Separator"` and `"MediaSkip"` have been removed, as they were deprecated and unused (Firefox bug 1232919).
* Key values and the corresponding key codes `"Hyper"` and `"Super"` have been added to represent these legacy modifier keys (Firefox bug 1232919).
* Two key values for multimedia numeric keypad keys have been added: `"Key11"` and `"Key12"` (Firefox bug 1232919).
* The following new key values have been added for audio control keys: `"AudioBassBoostToggle"`, `"AudioTrebleDown"`, and `"AudioTrebleUp"` (Firefox bug 123919).
* Key values have been added for these microphone control keys: `MicrophoneToggle`, `MicrophoneVolumeDown`, `MicrophoneVolumeUp`, and `MicrophoneVolumeMute` (Firefox bug 123919).
* New key values have been added to support speech recognition devices: `SpeechCorrectionList` and `SpeechInputToggle` (Firefox bug 1232919).
* New key values have been added to support special buttons on phones: `AppSwitch`, `Call`, `CameraFocus`, `EndCall`, `GoBack`, `GoHome`, `HeadsetHook`, `LastNumberRedial`, `Notification`, `MannerMode`, and `VoiceDial` (Firefox bug 1232919).
* These new application key values have been added: `LaunchContacts` and `LaunchPhone` (Firefox bug 1232919).
* New key values have been added to support television devices: `TV3DMode`, `TVAntennaCable`, `TVAudioDescription`, `TVAudioDescriptionMixDown`, `TVAudioDescriptionMixUp`, `TVContentsMenu`, `TVDataService`, `TVInput`, `TVInputComponent1`, `TVInputComponent2`, `TVInputComposite1`, `TVInputComposite2`, `TVInputHDMI1`, `TVInputHDMI2`, `TVInputHDMI3`, `TVInputHDMI4`, `TVInputVGA1`, `TVMediaContext`, `TVNetwork`, `TVNumberEntry`, `TVRadioService`, `TVSatellite`, `TVSatelliteBS`, `TVSatelliteCS`, `TVSatelliteToggle`, `TVTerrestrialAnalog`, `TVTerrestrialDigital`, `TVTimer`, and `DVR` (Firefox bug 1232919).
* The key value `MediaSelect` has been replaced with the standard `LaunchMediaPlayer` key value (Firefox bug 1272592).
* Additional media player key values have been added as well. These are `MediaAudioTrack`, `MediaSkipBackward`, `MediaSkipForward`, `MediaStepBackward`, `MediaStepForward`, `MediaTopMenu`, `NavigateIn`, `NavigateNext`, `NavigateOut`, and `NavigatePrevious` (Firefox bug 1232919).
#### Canvas
* The `CanvasRenderingContext2D.filter` property, which provides support for adding filters to a canvas, is now activated by default and no longer needs to be enabled using a preference (Firefox bug 1173545).
#### WebGL
* The `EXT_color_buffer_float` WebGL 2 extension has been implemented (Firefox bug 1129332).
* The `webglcontextcreationerror` event, which is sent when a WebGL context creation attempt fails, has been implemented (Firefox bug 1271478). Use this to help understand what went wrong, both for debugging and for production error handling.
#### IndexedDB
* You can now rename IndexedDB indexes; the `IDBIndex.name` property is no longer read-only (Firefox bug 1118028).
* You can also now rename `IDBObjectStore`s; the `IDBObjectStore.name` property is no longer read-only (Firefox bug 1118028).
#### Service Workers and related
* The Fetch API's `Response` object now implements the `redirected` property, which indicates whether or not the response is for a request which was redirected. Please review the security related notes in the documentation before using this property (Firefox bug 1243792).
* In the Permissions API, Firefox no longer supports the 'push' `PermissionDescriptor` dictionary type (referred to in the spec as `PushPermissionDescriptor`); this is because Firefox relies on a quota system for controlling the `userVisibleOnly` status instead, and was throwing an error when it encountered a `PushPermissionDescriptor` instance (Firefox bug 1266821). With this dictionary removed, Firefox now ignores it.
#### Media Streams
* In the past, it was possible for a call to `MediaDevices.getUserMedia()` which requests both audio and video to succeed in cases where the user has only one of the two types of hardware available. This has been fixed (Firefox bug 802326).
* In prior versions of Firefox, it was possible for a call to `MediaDevices.getUserMedia()` which requests both audio and video to succeed even though the user denied access to one but not both of the matching devices. This has been fixed (Firefox bug 802326). This involves minor user interface changes as well, to remove the options to choose "No audio" or "No video" when the user is prompted for permissions.
* The `MediaStream.getTrackById()` method has been implemented (Firefox bug 1208390).
#### WebRTC
* The `RTCPeerConnection.addTrack()` method has been updated to allow tracks which are not components of the specified streams to be added to the connection. Instead, the streams are used to group tracks on the receiving end of the connection (Firefox bug 1271669).
#### New APIs
* The `PerformanceObserver` API is now activated by default on Nightly. It is not available by default in other versions of Firefox 49 (Firefox bug 1271487).
#### Others
* `XMLHttpRequest.getResponseHeader()` and `XMLHttpRequest.getAllResponseHeaders()` return empty headers in case the preference `network.http.keep_empty_response_headers_as_empty_string` is set to `true` (Firefox bug 669259).
* The Firefox OS-only Data Store API has been removed (Firefox bug 1261009).
* The Fullscreen API event handlers `Document.onfullscreenchange` and `Document.onfullscreenerror` have been removed from `Element` as they were never fired there; the prefixed versions of these event handlers have been kept there for compatibility purposes, however (Firefox bug 1270386). Note that this is not yet activated by default, but is behind the `full-screen-api.unprefix.enabled` preference (Firefox bug 1268749).
* The obsolete `Document.mozFullScreen` property has been unprefixed to `Document.fullscreen` Firefox bug 1269157. Note that this is not yet activated by default by behind the `full-screen-api.unprefix.enabled` preference (Firefox bug 1268749).
* The read-only properties `Document.fullscreenElement` and `Document.fullscreenEnabled` no longer throw an exception if an attempt is made to change their values; instead, the new value is silently ignored and the setter function is a no-op (Firefox bug 1269798).
* Any kind of data can now be retrieved from the clipboard using `DataTransfer.getData()`: previously, only data of certain MIME types were supported Firefox bug 860857.
* Our implementation of the Frame Timing API, consisting of the two interfaces `PerformanceCompositeTiming` and `PerformanceRenderTiming`, has been removed as the spec has been completely rewritten (Firefox bug 1271846).
* To match the spec, the `VTTCue.positionAlign` property now returns a `PositionAlign` enum instead of an `Align` enum (Firefox bug 1276129).
* The speech synthesis part of Web Speech API is now activated by default (Firefox bug 1268633).
* The Performance Timeline API is now available by default in Nightly (though not in Aurora, Beta or Release).
* The `install` event, and the `Window.oninstall` event handler, are now supported for Web Manifests (Firefox bug 1265279).
* When using the `AudioContext.createPeriodicWave()` method of the Web Audio API, you can now specify whether the resulting periodic wave should be normalized by including a dictionary object as the third parameter, which includes a single parameter — `{disableNormalization: true}` (Firefox bug 1265405).
* In the WebVTT API, `VTTCue.positionAlign` now correctly returns a `PositionAlignSetting` enum as per spec; previously it returned an `AlignSetting` enum (Firefox bug 1276129).
* The Speech Synthesis part of the Web Speech API is now enabled by default across all desktop browsers (Firefox bug 1268633).
* The `Animation()` constructor of the Web Animations API now accepts a null timeline (Firefox bug 1096776).
* The `KeyframeEffect` property `target` is now supported in Firefox, if you have enabled Web Animations (Firefox bug 1067769).
### MathML
*No change.*
### SVG
* Removed support for the deprecated `<altGlyph>`, `<altGlyphDef>` and `<altGlyphItem>` elements (Firefox bug 1260032).
### Audio/Video
*No change.*
### Plugins and Flash
Beginning in Firefox 49, Firefox, by default, blocks certain kinds of Flash content that aren't necessary for sites to function well. This behavior, controlled by the preference `browser.safebrowsing.blockedURIs.enabled`, helps to improve the performance of sites and Firefox in general without having significant impact on site usability. It also helps improve stability of the browsing experience by eliminating a major cause of crashes. The blocked Flash modules include several used just for fingerprinting purposes, as well as a number of "supercookie" modules, and in the future may be expanded to include more types of blocked modules. See Firefox bug 1275591 for details.
This marks the next step in the journey toward a plugin-free future. HTML is very close to the point where plugins will no longer be needed to get the job done.
HTTP
----
* The `Cache-Control: immutable` directive has been implemented (Firefox bug 1267474). See also this blog post for more information.
* The `require-sri-for` `Content-Security-Policy` has been implemented (Firefox bug 1265318).
Networking
----------
* The Proxy Auto-Configuration (PAC) implementation has been updated. Now `weekdayRange`, `dateRange`, and `timeRange` support "reversed ranges", for example, `weekdayRange("SAT", "MON")` will evaluate `true` if the current day is Saturday, Sunday, or Monday (Firefox bug 1251332).
Security
--------
* The `isSecureContext` property, indicating whether a context is capable of using features that require secure contexts, has been implemented (Firefox bug 1162772).
Compatibility
-------------
In order to improve compatibility with existing content, Firefox now accepts some WebKit prefixed properties and attributes.
* The following properties now also work prefixed with `-webkit`:
+ `-webkit-align-items`
+ `-webkit-align-content`
+ `-webkit-align-self`
+ `-webkit-animation`
+ `-webkit-animation-delay`
+ `-webkit-animation-direction`
+ `-webkit-animation-duration`
+ `-webkit-animation-fill-mode`
+ `-webkit-animation-iteration-count`
+ `-webkit-animation-name`
+ `-webkit-animation-play-state`
+ `-webkit-animation-timing-function`
+ `-webkit-backface-visibility`
+ `-webkit-background-clip`
+ `-webkit-background-origin`
+ `-webkit-background-size`
+ `-webkit-border-bottom-left-radius`
+ `-webkit-border-bottom-right-radius`
+ `-webkit-border-image`
+ `-webkit-border-top-left-radius`
+ `-webkit-border-top-right-radius`
+ `-webkit-border-radius`
+ `-webkit-box-shadow`
+ `-webkit-filter`
+ `-webkit-flex`
+ `-webkit-flex-basis`
+ `-webkit-flex-direction`
+ `-webkit-flex-flow`
+ `-webkit-flex-grow`
+ `-webkit-flex-shrink`
+ `-webkit-flex-wrap`
+ `-webkit-justify-content`
+ `-webkit-order`
+ `-webkit-perspective`
+ `-webkit-perspective-origin`
+ `-webkit-text-size-adjust`
+ `-webkit-transform`
+ `-webkit-transform-origin`
+ `-webkit-transform-style`
+ `-webkit-transition`
+ `-webkit-transition-delay`
+ `-webkit-transition-duration`
+ `-webkit-transition-property`
+ `-webkit-transition-timing-function`
+ `-webkit-user-select`
* The following properties map to the equivalent prefixed property:
+ `-webkit-box-flex`
+ `-webkit-box-ordinal-group`
+ `-webkit-box-orient`
+ `-webkit-box-align`
+ `-webkit-box-pack`
* For `<image>` values:
+ The following functions map to their unprefixed equivalents: `-webkit-linear-gradient()`, `-webkit-radial-gradient()`, `-webkit-repeating-linear-gradient()`, and `-webkit-repeating-radial-gradient()`.
+ The outdated `-webkit-gradient` is supported (and translated to a regular gradient)
* The following `display` values are translated:
+ `-webkit-box` to `-moz-box`
+ `-webkit-flex` to `flex`
+ `-webkit-inline-box` to `inline-flex`
+ `-webkit-inline-flex` to `-moz-inline-flex`
* The following properties are supported (and don't map to any unprefixed equivalent):
+ `-webkit-text-fill-color`
+ `-webkit-text-stroke-color`
+ `-webkit-text-stroke-width`
+ `-webkit-text-stroke`
* The `WebKitCSSMatrix` interface is an alias of `DOMMatrix`
* The following media query features have been implemented:
+ `-webkit-min-device-pixel-ratio` as an alias of `min-resolution` with the same value (in `dppx)`, though this feature is disabled by default (behind about:config pref `layout.css.prefixes.device-pixel-ratio-webkit`)
+ `-webkit-max-device-pixel-ratio` as an alias of `max-resolution` of the same value (in `dppx`); this feature is also disabled by default, behind the same about:config pref.
+ `-webkit-transform-3d` always matching, indicating 3d transform support.
Changes for add-on and Mozilla developers
-----------------------------------------
### WebExtensions
* Support for the `history` has been added. This provides access to the browser history, with methods available for searching the history, getting information about previously-visited pages, and adding and removing history entries.
* Added the `tabs.removeCSS()` method to the tabs API. This method lets you remove CSS which was previously injected by calling `tabs.insertCSS()`.
### Interfaces
* In `EventTarget.addEventListener()`, the value `mozSystemGroup`, active only in code running in XBL or in Firefox's chrome, is a `Boolean` which indicates if the listener is added to the system group. (Firefox bug 1274520)
### Other
*No change.*
Older versions
--------------
* Firefox 48 for developers
* Firefox 47 for developers
* Firefox 46 for developers
* Firefox 45 for developers
* Firefox 44 for developers
* Firefox 43 for developers
* Firefox 42 for developers
* Firefox 41 for developers
* Firefox 40 for developers
* Firefox 39 for developers
* Firefox 38 for developers
* Firefox 37 for developers
* Firefox 36 for developers
* Firefox 35 for developers
* Firefox 34 for developers
* Firefox 33 for developers
* Firefox 32 for developers
* Firefox 31 for developers
* Firefox 30 for developers
* Firefox 29 for developers
* Firefox 28 for developers
* Firefox 27 for developers
* Firefox 26 for developers
* Firefox 25 for developers
* Firefox 24 for developers
* Firefox 23 for developers
* Firefox 22 for developers
* Firefox 21 for developers
* Firefox 20 for developers
* Firefox 19 for developers
* Firefox 18 for developers |
Firefox 103 for developers - Mozilla | Firefox 103 for developers
==========================
This article provides information about the changes in Firefox 103 that will affect developers. Firefox 103 was released on July 26, 2022.
Changes for web developers
--------------------------
### HTML
#### Removals
* Support for the `<menuitem>` element has been removed along with the `dom.menuitem.enabled` preference.
For more details, see Bug 1372276.
### MathML
#### Removals
* The deprecated `scriptminsize` and `scriptsizemultiplier` attributes have been removed (Firefox bug 1772697).
### CSS
* The `backdrop-filter` property (which can be used to apply graphical effects such as blurring or color shifting to the area behind an element) is now available by default. It was earlier behind a preference setting (Firefox bug 1578503).
* The `scroll-snap-stop` property is now available (Firefox bug 1312165). You can use this property's `always` and `normal` values to specify whether or not to pass the snap points, even when scrolling fast.
* Support has been added for the `:modal` pseudo class. It selects all elements that are in a state in which they exclude all interaction with other elements until the interaction has been dismissed (Firefox bug 1768535).
* The `style` value for the `contain` property is now supported. You can use this value for properties that can have effects on more than just an element and its descendants for effects don't escape the containing element. For more information, see (Firefox bug 1463600).
### JavaScript
* Native Error types can now be serialized using the structured clone algorithm.
This includes `Error`, `EvalError`, `RangeError`, `ReferenceError`, `SyntaxError`, `TypeError`, `URIError` and `AggregateError`.
Serialized properties include the `name`, `message`, `cause`, `fileName`, `lineNumber` and `columnNumber`.
For `AggregateError` the `message`, `name`, `cause` and `errors` properties are serialized.
See Firefox bug 1556604 for more details.
### HTTP
No notable changes.
### Security
No notable changes.
### APIs
* `ReadableStream`, `WritableStream`, `TransformStream` are now Transferable objects, which means that ownership can be transferred when sharing the objects between a window and workers using `postMessage`, or when using `structuredClone()` to copy an object.
After transferring, the original object cannot be used.
See Firefox bug 1659025 for more details.
* `caches`, `CacheStorage`, and `Cache` now require a secure context; the properties/interfaces are not defined if used in an insecure context.
Previously `cache` would return a `CacheStorage` that would throw an exception if used outside of a secure context.
See Firefox bug 1112134 for more details.
### WebAssembly
No notable changes.
### WebDriver conformance (WebDriver BiDi, Marionette)
#### WebDriver BiDi
* Added a preference to disable experimental BiDi commands and events `remote.experimental.enabled` (Firefox bug 1777951).
* Added a `script` module with an experimental implementation of the `evaluate` command. Only available if `remote.experimental.enabled` is set to `true` (Firefox bug 1742979).
* Added serialization support for collections with simple values and complex objects, used for instance for the event data of `log.entryAdded` or the return value of `script.evaluate` (Firefox bug 1770752).
* Fixed an edge case for `browsingContext.navigate` when navigating to a cached image (Firefox bug 1763133).
#### Marionette
* Updated the `platformVersion` capability to be returned as `moz:platformVersion` (Firefox bug 1771760).
* Removed support for `ChromeElement`; all elements are now serialized as `WebElement` (Firefox bug 1775036 and Firefox bug 1775064).
Changes for add-on developers
-----------------------------
### Removals
* Removed the ServiceWorker API in WebExtensions (`'serviceWorker' in navigator` now returns `false` when run inside an extension) (Firefox bug 1593931).
Older versions
--------------
* Firefox 102 for developers
* Firefox 101 for developers
* Firefox 100 for developers
* Firefox 99 for developers
* Firefox 98 for developers
* Firefox 97 for developers
* Firefox 96 for developers
* Firefox 95 for developers
* Firefox 94 for developers
* Firefox 93 for developers
* Firefox 92 for developers
* Firefox 91 for developers
* Firefox 90 for developers
* Firefox 89 for developers
* Firefox 88 for developers
* Firefox 87 for developers
* Firefox 86 for developers
* Firefox 85 for developers
* Firefox 84 for developers
* Firefox 83 for developers
* Firefox 82 for developers
* Firefox 81 for developers
* Firefox 80 for developers
* Firefox 79 for developers
* Firefox 78 for developers
* Firefox 77 for developers
* Firefox 76 for developers
* Firefox 75 for developers
* Firefox 74 for developers
* Firefox 73 for developers
* Firefox 72 for developers |
Firefox 91 for developers - Mozilla | Firefox 91 for developers
=========================
This article provides information about the changes in Firefox 91 that will affect developers. Firefox 91 was released on August 10, 2021.
**Note:** See also Hopping on Firefox 91 on Mozilla Hacks.
Changes for web developers
--------------------------
### HTML
No changes
### CSS
* A fix to how the `@counter-style/pad` descriptor handles the negative sign (Firefox bug 1714445).
* The `-moz-tab-size` property has been unprefixed to the standard `tab-size`, and the prefixed version maintained as an alias (Firefox bug 737785).
#### Removals
* The non-standard `-moz-outline-radius` property has been removed (Firefox bug 1715984). The property has not been usable by web developers since Firefox 88, this completes the removal.
### JavaScript
* `Intl.DateTimeFormat.prototype.formatRange()` and `Intl.DateTimeFormat.prototype.formatRangeToParts()` are now supported in release builds. The `formatRange()` method returns a localized and formatted string for the range between two `Date` objects (e.g. "1/05/21 – 1/10/21"). The `formatRangeToParts()` method returns an array containing the locale-specific *parts* of a formatted date range (Firefox bug 1653024).
* The `Intl.DateTimeFormat() constructor` allows four new `timeZoneName` options for formatting how the timezone is displayed. These include the localized GMT formats `shortOffset` and `longOffset`, and the generic non-location formats `shortGeneric` and `longGeneric` (Firefox bug 1653024).
* The `Error() constructor` can now take the error `cause` as value in the `option` parameter.
This allows code to catch errors and throw new/modified versions that retain the original error and stack trace (Firefox bug 1679653).
### HTTP
* The Gamepad API now requires a secure context (Firefox bug 1704005).
### APIs
#### DOM
* The Visual Viewport API is now enabled by default on Firefox desktop releases (it has been enabled on Firefox for Android since version 68).
The API provides access to information describing the position of the visual viewport relative to the document, as well as to the window's content area.
It also provides events that allow changes to the viewport to be monitored. (Firefox bug 1551302).
* The Gamepad API is now protected by `Feature-Policy: gamepad`.
If disallowed by the Permission Policy, calls to `Navigator.getGamepads()` will throw a `SecurityError` `DOMException`,
and the `gamepadconnected` and `gamepaddisconnected` events will not fire.
The default `allowlist` is `*`; this default will be updated to `self` in a future release, in order to match the specification. (Firefox bug 1704005).
* `Window.clientInformation` has been added as an alias for `Window.navigator`, in order to match recent specification updates and improve compatibility with other major browsers (Firefox bug 1717072).
* Changing the playback speed of a media element (`<video>` or `<audio>`) using the `playbackRate` attribute now works when the media element is captured to a `MediaStream` or via `AudioContext.createMediaElementSource` (Firefox bug 1517199).
### WebDriver conformance (Marionette)
* Fixed a bug, which caused the commands `WebDriver:AcceptAlert` and `WebDriver:DismissAlert` to hang for user prompts as opened in a popup window (Firefox bug 1721982).
* Fixed an inappropriate handling of the `webSocketUrl` capability, which would return `true` if `webSocketUrl` was not supported (Firefox bug 1713775).
Older versions
--------------
* Firefox 90 for developers
* Firefox 89 for developers
* Firefox 88 for developers
* Firefox 87 for developers
* Firefox 86 for developers
* Firefox 85 for developers
* Firefox 84 for developers
* Firefox 83 for developers
* Firefox 82 for developers
* Firefox 81 for developers
* Firefox 80 for developers
* Firefox 79 for developers
* Firefox 78 for developers
* Firefox 77 for developers
* Firefox 76 for developers
* Firefox 75 for developers
* Firefox 74 for developers
* Firefox 73 for developers
* Firefox 72 for developers
* Firefox 71 for developers
* Firefox 70 for developers
* Firefox 69 for developers
* Firefox 68 for developers
* Firefox 67 for developers
* Firefox 66 for developers
* Firefox 65 for developers
* Firefox 64 for developers
* Firefox 63 for developers
* Firefox 62 for developers
* Firefox 61 for developers
* Firefox 60 for developers |
Firefox 78 for developers - Mozilla | Firefox 78 for developers
=========================
This article provides information about the changes in Firefox 78 that will affect developers. Firefox 78 was released on June 30, 2020.
See also New in Firefox 78: DevTools improvements, new regex engine, and abundant web platform updates on Mozilla hacks.
Changes for web developers
--------------------------
### Developer Tools
#### Debugger
* You can now change the URL accessed by the remote device from the about:debugging panel. (Firefox bug 1617237)
* The **Disable JavaScript** menu item in the Debugger now only affects the current tab, and is reset when the Developer Tools are closed. (Firefox bug 1640318)
* Logpoints can map variable names in source-mapped code back to their original names, if you enable **Maps** in the Scopes pane. (Firefox bug 1536857)
#### Network Monitor
* In the Network Monitor, you can now resize the columns of the request list by dragging the column borders anywhere in the table. (Firefox bug 1618409)
* The request details panel in the Network Monitor has some UX improvements. (Firefox bug 1631302, Firefox bug 1631295)
* If a request was blocked, the request list now shows the reason, such as an add-on, CSP, CORS, or Enhanced Tracking Protection. (Firefox bug 1555057, Firefox bug 1445637, Firefox bug 1556451)
#### Other tools
* The Accessibility inspector is out of beta. You can use it to check for various accessibility issues on your site. (Firefox bug 1602075)
* Uncaught promise errors now provide all details in the Console, including their name and stack. (Firefox bug 1636590)
### CSS
* The `:is()` and `:where()` pseudo-classes are now enabled by default (Firefox bug 1632646).
* The `:read-only` and `:read-write` pseudo-classes are now supported without prefixes (Firefox bug 312971).
+ In addition, `:read-write` styles are no longer applied to disabled `<input>` and `<textarea>` elements, which was a violation of the HTML spec (Firefox bug 888884).
### JavaScript
* The `Intl.ListFormat` API is now supported (Firefox bug 1589095).
* The `Intl.NumberFormat()` constructor has been extended to support new options specified in the Intl.NumberFormat Unified API Proposal (Firefox bug 1633836). This includes among other things:
+ Support for scientific notations
+ Unit, currency and sign display formatting
* The `RegExp` engine has been updated and now supports all new features introduced in ECMAScript 2018:
+ Lookbehind assertions (Firefox bug 1225665)
+ `RegExp.prototype.dotAll` (Firefox bug 1361856)
+ Unicode property escapes (Firefox bug 1361876)
+ Named capture groups (Firefox bug 1362154)
* Due to a WebIDL spec change in mid-2020, we've added a `Symbol.toStringTag` property to all DOM prototype objects (Firefox bug 1277799).
* The garbage collection of `WeakMap` objects has been improved. `WeakMaps` are now marked incrementally (Firefox bug 1167452).
### APIs
#### DOM
* The `Element.replaceChildren` method has been implemented (Firefox bug 1626015).
#### Service workers
* Extended Support Releases (ESR): Firefox 78 is the first ESR release that supports Service workers (and the Push API). Earlier ESR releases had no support (Firefox bug 1547023).
### WebAssembly
* Wasm Multi-value is now supported, meaning that WebAssembly functions can now return multiple values, and instruction sequences can consume and produce multiple stack values (Firefox bug 1628321).
* WebAssembly now supports import and export of 64-bit integer function parameters (i64) using `BigInt` from JavaScript (Firefox bug 1608770).
### TLS 1.0 and 1.1 removal
* Support for the Transport Layer Security (TLS) protocol's version 1.0 and 1.1, is dropped from all browsers. Read TLS 1.0 and 1.1 Removal Update for the previous announcement and what actions to take if you are affected (Firefox bug 1643229).
Changes for add-on developers
-----------------------------
* `browsingData.removeCache` and `browsingData.removePluginData` now support deleting by hostname. (Firefox bug 1636784).
* When using `proxy.onRequest`, a filter that limits based on tab id or window id is now correctly applied. This could be useful for add-ons that want to provide proxy functionality just in just one window.
* Clicking within the context menu from the "all tabs" dropdown now passed the appropriate tab object. In the past, the active tab was erroneously passed.
* When using `downloads.download` with the saveAs option, the recently used directory is now remembered. While this information is not available to developers, it is very convenient to users.
Older versions
--------------
* Firefox 77 for developers
* Firefox 76 for developers
* Firefox 75 for developers
* Firefox 74 for developers
* Firefox 73 for developers
* Firefox 72 for developers
* Firefox 71 for developers
* Firefox 70 for developers
* Firefox 69 for developers
* Firefox 68 for developers
* Firefox 67 for developers
* Firefox 66 for developers
* Firefox 65 for developers
* Firefox 64 for developers
* Firefox 63 for developers
* Firefox 62 for developers
* Firefox 61 for developers
* Firefox 60 for developers
* Firefox 59 for developers
* Firefox 58 for developers
* Firefox 57 for developers
* Firefox 56 for developers
* Firefox 55 for developers
* Firefox 54 for developers
* Firefox 53 for developers
* Firefox 52 for developers
* Firefox 51 for developers
* Firefox 50 for developers
* Firefox 49 for developers
* Firefox 48 for developers
* Firefox 47 for developers |
Firefox 1.5 for developers - Mozilla | Firefox 1.5 for developers
==========================
Based on the Gecko 1.8 engine, Firefox 1.5 improved its already best in class standards support, and provided new capabilities to enable the next generation of web applications. Firefox 1.5 features improved support for CSS2 and CSS3, APIs for scriptable and programmable 2D graphics through SVG 1.1 and `<canvas>`, XForms and XML events, as well as many DHTML, JavaScript, and DOM enhancements.
Developer Tools
---------------
Several tools and browser extensions are available to help developers support Firefox 1.5.
* DOM Inspector, a tool that allows developers to inspect and modify documents without having to edit the document directly. DOM Inspector is available as part of the Custom install option in Firefox 1.5 under Developer Tools.
* JavaScript console, a tool to write and test JavaScript code as well as view JavaScript and CSS errors on a page.
* View page source, with syntax highlighting and find features.
* Browser extensions including the FireBug, Web Developer toolbar, Live HTTP Headers, HTML Validator and many more.
**Note:** Some extensions do not currently support Firefox 1.5, and will be automatically disabled.
Overview
--------
Some of the new features in Firefox 1.5:
### Website and application developers
SVG is supported in XHTML
SVG can be used in XHTML pages. JavaScript and CSS can be used to manipulate the picture in the same way you would script regular XHTML. See SVG in Firefox to learn about the status and known problems of SVG implementation in Firefox.
Drawing Graphics with Canvas
Learn about the new `<canvas>` tag and how to draw graphs and other objects in Firefox.
CSS3 Columns
Learn about the new support for automatic multi-column text layout as proposed for CSS3.
Using Firefox 1.5 caching
Learn about `bfcache` and how it speeds up back and forward navigation.
### XUL and Extension Developers
Building an Extension
This tutorial will take you through the steps required to build a very basic extension for Firefox. Also see another tutorial on MozillaZine knowledge base, which demonstrates the new features of the Extension Manager in 1.5 that make creating a new extension even easier.
XPCNativeWrapper
`XPCNativeWrapper` is a way to wrap up an object so that it's safe to access from privileged code. It can be used in all Firefox versions, though the behavior changed somewhat starting with Firefox 1.5 (Gecko 1.8).
Preferences System
Learn about the new widgets that allow you to create Options windows easier using less JavaScript code.
International characters in XUL JavaScript
XUL JavaScript files can now contain non-ASCII characters.
Tree API changes
The interfaces for accessing XUL `<tree>` elements have changed.
XUL Changes for Firefox 1.5
Summary of XUL changes. See also Adapting XUL Applications for Firefox 1.5.
#### Networking-related changes
* Certificate prompts can now be overridden on a per-channel basis. This works by setting an interface requester as an `nsIChannel`'s notificationCallbacks and giving out an interface for `nsIBadCertListener`.
* nsIWebBrowserPersist's listeners can now implement `nsIInterfaceRequestor::GetInterface` and will get an opportunity to provide all interfaces that channels might ask for, including `nsIProgressEventSink` (not too useful, redundant with `nsIWebProgressListener`). Useful interfaces here include `nsIChannelEventSink` and `nsIBadCertListener`.
* Extensions or other necko consumers, including XMLHttpRequest, can set a Cookie header explicitly, and necko will not replace it. Stored cookies will be merged with the explicitly set header, in a way that the explicit header will override the stored cookies.
New End user Features
---------------------
### User Experience
* **Faster browser navigation** with improvements to back and forward button performance.
* **Drag and drop reordering for browser tabs.**
* **Answers.com is added to the search engine list** for dictionary lookup.
* **Improvements to product usability** including descriptive error pages, redesigned options menu, RSS discovery, and "Safe Mode" experience.
* **Better accessibility support** including DHTML accessibility.
* **Report a broken website wizard** to report websites that are not working in Firefox.
* **Better support for Mac OS X** (10.2 and greater) including profile migration from Safari and Mac Internet Explorer.
### Security and Privacy
* **Automated update** to streamline product upgrades. Notification of an update is more prominent, and updates to Firefox may now be half a megabyte or smaller. Updating extensions has also improved.
* **Improvements to popup blocking.**
* **Clear Private Data** feature provides an easy way to quickly remove personal data through a menu item or keyboard shortcut.
### Support for open Web standards
Firefox support for Web standards continues to lead the industry with consistent cross-platform implementations for:
* Hypertext Markup Language (HTML) and Extensible Hypertext Markup Language (XHTML): HTML 4.01 and XHTML 1.0/1.1
* Cascading Style Sheets (CSS): CSS Level 1, CSS Level 2 and parts of CSS Level 3
* Document Object Model (DOM): DOM Level 1, DOM Level 2 and parts of DOM Level 3
* Mathematical Markup Language: MathML Version 2.0
* Extensible Markup Language (XML): XML 1.0, Namespaces in XML, Associating Style Sheets with XML Documents 1.0, Fragment Identifier for XML
* XSL Transformations (XSLT): XSLT 1.0
* XML Path Language (XPath): XPath 1.0
* Resource Description Framework (RDF): RDF
* Simple Object Access Protocol (SOAP): SOAP 1.1
* JavaScript 1.6, based on ECMA-262, revision 3
Firefox 1.5 supports the following data transport protocols (HTTP, FTP, SSL, TLS, and others), multilingual character data (Unicode), graphics (GIF, JPEG, PNG, SVG, and others) and the latest version of the world's most popular scripting language, JavaScript 1.6.
Changes since Firefox 1.0
-------------------------
Many changes have been introduced into Firefox since it was first released on November 9, 2004. Firefox has progressed with many new features and bug fixes. A detailed list of changes is available from squarefree.com. |
Firefox 33 for developers - Mozilla | Firefox 33 for developers
=========================
Firefox 33 was released on October 14, 2014. This article lists key changes that are useful not only for web developers, but also Firefox and Gecko developers as well as add-on developers.
Changes for Web developers
--------------------------
### Developer Tools
Highlights
* Event listeners popup
* @media sidebar
* Add new rule
* Edit keyframes
* Cubic bezier editor
* Transform highlighter
* Persistent disable cache
* New Commands
* Editor preferences
* WebIDE
For details please see the hacks post. Special thanks to the 33 contributors that added all the features and fixes in this release.
### CSS
* Implemented `@counter-style` rule (Firefox bug 966166).
* Unprefixed `ethiopic-numeric`, `persian`, `arabic-indic`, `devanagari`, `bengali`, `gurmukhi`, `gujarati`, `oriya`, `tamil`, `telugu`, `kannada`, `malayalam`, `thai`, `lao`, `myanmar`, `khmer`, `cjk-heavenly-stem`, `cjk-earthly-branch` in `list-style-type` (Firefox bug 985825 and Firefox bug 1063856).
* Added support for `mongolian`, `disclosure-open` and `disclosure-closed` counter styles in `list-style-type` (Firefox bug 982355 and Firefox bug 1063856).
* Fixed CSS animations with empty keyframes rule so they also dispatch events (Firefox bug 1004377).
* Added support for `rebeccapurple`, a new `<color>` name defined in CSS Colors level 4 (Firefox bug 1024642).
* Our experimental implementation of CSS Fonts Level 3 is progressing. Its activation is governed by the `layout.css.font-features.enabled` preference, enabled by default in Nightly. Newly implemented features are:
+ The fallback algorithm of `font-variant-caps`, creating synthetic alternates for missing glyphs (Firefox bug 961558).
+ The `font-synthesis` CSS property has been implemented (Firefox bug 871453).
### HTML
* Added the experimental support for `<picture>` element (Firefox bug 870022), behind the `dom.image.picture.enabled` preference (off by default).
* The `<label>`, especially without a `for` attribute, doesn't apply anymore to a `<input type=hidden>` field (Firefox bug 597650). The previous behavior wasn't spec-compliant.
* The link annotation `noreferrer` has been implemented on `<a>` elements. `<a rel="noreferrer">` will not include the URL of the referrer in the HTTP request sent to fetch it (Firefox bug 530396). Note that this works only for in-page links, not for links clicked via the UI, like via contextual menus.
* On Android, support for two new values for the `name` attribute of `<meta>` has been added: `msapplication-TileImage` and `msapplication-TileColor` (Firefox bug 1014712). Example:
```html
<meta name="msapplication-TileImage" content="images/benthepcguy-144.png" />
<meta name="msapplication-TileColor" content="#d83434" />
```
### JavaScript
* The non-standard method `Number.toInteger()` has been removed (Firefox bug 1022396).
* The `Map.prototype.set()`, `WeakMap.prototype.set()` and `Set.prototype.add()` methods are now chainable, return their equivalent objects and no longer `undefined` (Firefox bug 1031632).
* A default parameter is evaluated before function declarations inside the function body, so those functions cannot be referred from the default parameter (Firefox bug 1022962).
* Shorthand properties are now allowed in object literals: if not explicitly defined, property keys are initialized by variables of the same name. E.g. `function f(x, y) { return {x, y}; }` is equivalent to `function f(x, y) { return {x: x, y: y}; }` (Firefox bug 875002).
* The parsing of `yield` and `yield*` has been updated to conform with the latest ES2015 specification (Firefox bug 981599).
* The non-standard `hasOwn` trap has been removed (Firefox bug 980565).
### Interfaces/APIs/DOM
* The `RadioNodeList` API has been implemented and the selected radio button is accessible via `RadioNodeList.value` (Firefox bug 779723).
* The `DOMMatrix` has been added (Firefox bug 1018497).
* A non-standard (but implemented in other browsers) `DOMException.stack` property has been added. It returns a string with a human-friendly formatted stack (Firefox bug 857648), in the same format as the existing non-standard `Error.stack` property.
* For `<canvas>`, the method `CanvasPattern.setTransform()`, allowing to modify a pattern using the `DOMMatrix` representation of a linear transform (Firefox bug 1019257).
* Our experimental implementation of Media Source Extensions, behind the `media.mediasource.enabled` preference, enabled by default in Nightly and Aurora only, now supports MP4 (Firefox bug 1000686).
* The properties `HTMLMediaElement.audioTracks` and `HTMLMediaElement.videoTracks` have been experimentally implemented. They are controlled by the `media.track.enabled`, off by default (Firefox bug 744896).
* The non-standard `XMLHttpRequest.mozBackgroundRequest()` is no more accessible from websites. Only Firefox-internal code (Chrome code) can use it (Firefox bug 1035242).
* The `touchenter` and `touchleave` events, removed from the specification, have been removed (Firefox bug 1036444).
* The formerly called `loaded` event, sent on a `HTMLTrackElement` has been renamed `load` to match the specification (Firefox bug 1035505).
* The IndexedDB interface `FileHandle` has been renamed in `IDBMutableFile` (Firefox bug 1006485).
* The IndexedDB interface `LockedFile` has been renamed in `IDBFileHandle` (Firefox bug 1006485).
* The `ServiceWorker` interface has been implemented behind the `dom.serviceWorkers.enabled` flag (Firefox bug 903441).
* The `NetworkInformation.type` now also support the `"unknown"` value (Firefox bug 1023029).
### MathML
* The attributes `columnspacing`, `framespacing`, and `rowspacing` of the `<mtable>` element are now supported (Firefox bug 330964).
* Use Open Type MATH constants for fractions, stacks, radicals, and scripts (Firefox bug 961365).
### SVG
*No change.*
### Audio/Video/WebRTC
* The `RTCOfferOptions` dictionary, used to provide options when calling `RTCPeerConnection.createOffer()`, has been implemented.
### WebGL
* `EXT_blend_minmax` is now exposed. It extends blending capabilities by adding two new blend equations: producing the minimum or maximum color components of the source and destination colors (Firefox bug 973815).
Security
--------
* The CSP 1.1 `frame-ancestors` directive is now supported (Firefox bug 846978).
Changes for add-on and Mozilla developers
-----------------------------------------
* The JavaScript Debugger Service (JSD) has been removed in favor of the new Debugger API (Firefox bug 800200).
* The interface nsIX509CertDB2 has been removed and the methods from that interface have been moved to the nsIX509CertDB interface.
### Add-on SDK
#### Highlights
* Added support for context menus in panels via a new option in the `Panel` constructor.
* Added `tab.readyState`.
* Added a `BrowserWindow` parameter to `sidebar.show()` and `sidebar.hide()`, to control the window for which the sidebar will be shown or hidden.
#### Details
GitHub commits made between Firefox 32 and Firefox 33. This will not include any uplifts made after this release entered Aurora.
Bugs fixed between Firefox 32 and Firefox 33. This will not include any uplifts made after this release entered Aurora.
### Older versions
* Firefox 32 for developers
* Firefox 31 for developers
* Firefox 30 for developers
* Firefox 29 for developers
* Firefox 28 for developers
* Firefox 27 for developers
* Firefox 26 for developers
* Firefox 25 for developers
* Firefox 24 for developers
* Firefox 23 for developers
* Firefox 22 for developers
* Firefox 21 for developers
* Firefox 20 for developers
* Firefox 19 for developers
* Firefox 18 for developers
* Firefox 17 for developers
* Firefox 16 for developers
* Firefox 15 for developers
* Firefox 14 for developers
* Firefox 13 for developers
* Firefox 12 for developers
* Firefox 11 for developers
* Firefox 10 for developers
* Firefox 9 for developers
* Firefox 8 for developers
* Firefox 7 for developers
* Firefox 6 for developers
* Firefox 5 for developers
* Firefox 4 for developers
* Firefox 3.6 for developers
* Firefox 3.5 for developers
* Firefox 3 for developers
* Firefox 2 for developers
* Firefox 1.5 for developers |
Firefox 51 for developers - Mozilla | Firefox 51 for developers
=========================
To test the latest developer features of Firefox, install Firefox Developer EditionFirefox 51 was released on January 24, 2017. This article lists key changes that are useful not only for web developers, but also Firefox and Gecko developers as well as add-on developers.
Changes for Web developers
--------------------------
### HTML
* `<hr>` elements can now be used as separators in `<menu>` elements (Firefox bug 870388).
* The `<input>` and `<textarea>` elements' `selectionStart` and `selectionEnd` attributes now correctly return the current position of the text input cursor when there's no selection, instead of returning 0 (Firefox bug 1287655).
### CSS
* Implemented `:indeterminate` for <input type="radio"> (Firefox bug 885359).
* Implemented `:placeholder-shown` for `<input type="text">` (Firefox bug 1069015).
* The `::placeholder` pseudo-element is now unprefixed (Firefox bug 1069012).
* Fixed the `:valid` CSS pseudo-class which didn't match valid `<form>` elements (Firefox bug 1285425).
* The `plaintext` value of `unicode-bidi` now also works with vertical writing modes (Firefox bug 1302734).
* The `fill-box` and `stroke-box` values of `clip-path` are now properly supported; previously, they were aliases of `border-box` (Firefox bug 1289011).
* Clamp flex line's height (clamping stretched flex items), in single-line auto-height flex container w/ max-height (spec change) (Firefox bug 1000957).
### JavaScript
* The ES2015 `Symbol.toStringTag` property has been implemented (Firefox bug 1114580).
* The ES2015 `TypedArray.prototype.toString()` and `TypedArray.prototype.toLocaleString()` methods have been implemented (Firefox bug 1121938).
* The `DateTimeFormat.prototype.formatToParts()` method is now available (Firefox bug 1289340).
* `const` and `let` are now fully ES2015-compliant (Firefox bug 950547).
* Using `const` in `for...of` loops now has a fresh binding for each iteration and no longer throws a `SyntaxError` (Firefox bug 1101653).
* The deprecated for each...in loop now presents a warning in the console (Firefox bug 1293205). Please migrate your code to use the standardized `for...of` loop.
* Generator functions can't have a label anymore and "`let`" as a label name is disallowed now (Firefox bug 1288459).
* Deprecated legacy generator functions will now throw when used in method definitions (Firefox bug 1199296).
* The `next()` method of the iterator protocol will now throw a `TypeError` if the returned value is not an object (Firefox bug 1016936).
* Child-indexed pseudo-class selectors should match without a parent (Firefox bug 1300374).
### Developer Tools
* Network Monitor now shows a "Blocked" state for network requests.
* All devtools bugs fixed between Firefox 50 and Firefox 51.
### WebGL
* WebGL 2 is now enabled by default. See webglsamples.org/WebGL2Samples for a few demos.
+ WebGL 2 provides the `WebGL2RenderingContext` interface that brings OpenGL ES 3.0 to the `<canvas>` element.
+ New features include:
- 3D textures,
- Sampler objects,
- Uniform Buffer objects,
- Sync objects,
- Query objects,
- Transform Feedback objects,
- Promoted extensions that are now core to WebGL 2: Vertex Array objects, instancing, multiple render targets, fragment depth.
* The `WEBGL_compressed_texture_es3` extension (implemented in Firefox 46) has been renamed to `WEBGL_compressed_texture_etc` (Firefox bug 1316778) and is no longer included by default in WebGL 2 contexts (Firefox bug 1306174).
* The `EXT_disjoint_timer_query` extension has been updated to use `WebGLQuery` objects instead of `WebGLTimerQuery` objects (Firefox bug 1308057).
* The `OES_vertex_array_object` extension now uses the WebGL 2 `WebGLVertexArrayObject` object instead of its own `WebGLVertexArrayObjectOES` object (Firefox bug 1318523).
* You can now use `ImageBitmap` objects as a sources for texture images in methods like `WebGLRenderingContext.texImage2D()`, `WebGLRenderingContext.texSubImage2D()`, `WebGL2RenderingContext.texImage3D()`, or `WebGL2RenderingContext.texSubImage3D()` (Firefox bug 1324924).
### IndexedDB v2
* IndexedDB version 2 implementation is now complete:
+ Supports for the new `IDBObjectStore.getKey()` method has been added (Firefox bug 1271506).
+ Supports for `IDBCursor.continuePrimaryKey()` method has been added (Firefox bug 1271505).
+ Binary keys are now supported (Firefox bug 1271500).
+ See also "What's new in IndexedDB 2.0?" – Mozilla hacks
### Canvas
* The non-standard `CanvasRenderingContext2D.mozFillRule()` method has been removed; the fill rule can be defined using a parameter of the standard `CanvasRenderingContext2D.fill()` method (Firefox bug 826619).
* The `CanvasRenderingContext2D.imageSmoothingEnabled` has been unprefixed (Firefox bug 768072)
### SVG
* Added `tabindex` attribute (Firefox bug 778654).
* Added `href` attribute, which renders `xlink:href` obsolete (Firefox bug 1245751).
* You can now use custom data attributes on SVG elements through the `HTMLElement.dataset` property and the `data-\*` set of SVG attributes (Firefox bug 921834).
* CSS Animations used in an SVG image which is presented in an `<img>` element now work again; this was an old regression (Firefox bug 1190881).
### Web Workers
* The non-standard and obsolete `DedicatedWorkerGlobalScope.close` event handler and `Worker` use of the `close` event have been removed from Firefox.
### Networking
* Scripts served with an `image/*`, `video/*`, `audio/*` or `text/csv` MIME type are now blocked and are not loaded or executed. This happen when they are declared using `<script>`, or loaded via `Worker.importScripts()`, `Worker()`, `SharedWorker()` (Firefox bug 1229267 and Firefox bug 1288361).
* Support for SHA-1 certificates from publicly-trusted certificate authorities has been removed (Firefox bug 1302140). See also Phasing Out SHA-1 on the Public Web for more information.
* New WoSign and StartCom certificates will no longer be accepted (Firefox bug 1309707), see Distrusting New WoSign and StartCom Certificates for more information.
* The PAC `FindProxyForURL(url, host)` function now strips paths and queries from https:// URLs to avoid information leakage (see Firefox bug 1255474, Sniffing HTTPS URLS with malicious PAC files, or `CVE-2017-5384`).
### XHR
* The `XMLHttpRequest.responseXML` property no longer returns a partial `Document` with a <parsererror> node placed at the top when a parse error occurs attempting to interpret the received data. Instead, it correctly returns `null` (Firefox bug 289714).
* To match the latest specification an `XMLHttpRequest` without an `Accept` header set with `setRequestHeader()` is now sent with such a header, with its value set to `*/*` (Firefox bug 918752).
* Fixed `XMLHttpRequest.open()` so that, when omitted, the `username` and `password` parameters now default to `null`, per the specification (Firefox bug 933759).
### WebRTC
* The `RTCPeerConnection.removeStream()` method has been removed. It was deprecated back in Firefox 22, and has been throwing a `NotSupportedError` `DOMException` for a long time. You need to use `RTCPeerConnection.removeTrack()` instead, for each track on the stream.
* WebRTC now supports the VP9 codec by default. When added in Firefox 46, VP9 was disabled by default, but when enabled was the preferred codec; however, it has been moved to be the second choice (after VP8) due to its current level of CPU usage.
* The method `HTMLMediaElement.captureStream()`, which returns a `MediaStream` containing the content of the specified `<video>` or `<audio>`. It's worth noting that this is prefixed still as `mozCaptureStream()`, and that it doesn't yet exactly match the spec.
### Audio/video
* Added FLAC support (FLAC codec) in both FLAC and Ogg containers (Firefox bug 1195723). Supported FLAC MIME types are: `audio/flac` and `audio/x-flac`. For FLAC in Ogg, supported MIME types are: `audio/ogg; codecs=flac`, and `video/ogg; codecs=flac`.
* Added support for FLAC in MP4 (both with and without MSE) (Firefox bug 1303888).
* Throttling in background tabs of timers created by `setInterval()` and `setTimeout()` was changed in Firefox 50 to no longer occur if a Web Audio API `AudioContext` is actively playing sound. However, this didn't resolve all scenarios in which timing-sensitive audio playback (such as music players generating individual notes using timers) could fail to work properly. For that reason, Firefox 51 no longer throttles background tabs which have an `AudioContext`, even if it's not currently playing sound.
### DOM
* The `DOMImplementation.hasFeature()` now returns `true` in all cases (Firefox bug 984778).
* The `HTMLInputElement` and `HTMLTextAreaElement` properties `selectionStart` and `selectionEnd` now correctly return the current position of the text input cursor when there's no selection, instead of returning 0 (Firefox bug 1287655).
* The `HTMLImageElement` interface and the corresponding `<img>` element now support the `onerror` event handler, sending `error` events to the element whenever errors occur attempting to load or interpret images.
* You can now change a Web `Animation`'s effect by setting the value of its `effect` property. Previously, this property was read-only (Firefox bug 1049975).
* The Permissions API method `Permissions.revoke()` has been put behind a preference (`dom.permissions.revoke.enable`) and disabled by default since its design and even its very existence is under discussion in the Web Application Security Working Group.
* The Storage API's `Navigator.storage` property and `StorageManager.estimate()` method have been implemented along with the needed supporting code. Storage unit persistence features are not yet implemented. See Firefox bug 1267941.
* For privacy reasons, both `BatteryManager.chargingTime` and `BatteryManager.dischargingTime` now round the returned value to the closest 15 minutes (Firefox bug 1292655).
### Events
* Firefox now supports the `onanimationstart`, `onanimationiteration`, and `onanimationstart` event handlers, in addition to supporting the corresponding events using `addEventListener()` (Firefox bug 911987).
* Firefox now supports the `ontransitionend` event handler (Firefox bug 911987).
### Security
* When login pages (i.e., those containing an `<input type="password">` field) are created so that they would be submitted insecurely, Firefox displays a crossed-out lock icon in the address bar to warn users (Firefox bug 1319119). See Insecure passwords for more details.
### Removals
* The non-standard Simple Push API, mainly intended for use with Firefox OS and now superseded by the W3C Push API, has been completely removed from Gecko (Firefox bug 1296579).
* The non-standard Alarms API, mainly intended for use with Firefox OS, has been completely removed from Gecko (Firefox bug 1300884).
* Support for prefixes in the Page Visibility API has been removed (Firefox bug 812701).
Changes for add-on and Mozilla developers
-----------------------------------------
### WebExtensions
* New APIs:
+ `idle.queryState()` (Firefox bug 1299846)
+ `idle.onStateChanged` (Firefox bug 1299775)
+ `management.getSelf()` (Firefox bug 1283116)
+ `management.uninstallSelf()` (Firefox bug 1220136)
+ `runtime.getBrowserInfo()` (Firefox bug 1268399)
+ `runtime.reload()` and `runtime.onUpdateAvailable()` (Firefox bug 1279012)
* You can now embed a WebExtension in a legacy add-on type (Firefox bug 1252215).
* Clipboard access is now supported (Firefox bug 1197451)
* The arguments passed to the callback of `tabs.executeScript()` have been fixed (Firefox bug 1290157)
* localStorage is now cleared when a WebExtension is uninstalled (Firefox bug 1213990)
* A changed `Content-Type` header in Web Extensions is now taken into account (Firefox bug 1304331)
### Other
* The `multiprocessCompatible` property of `install.rdf` must now be explicitly set to `false` to prevent multiprocess from being enabled in Firefox when the add-on is installed.
* The Mozilla-specific Social API has been substantially changed (largely to remove APIs no longer used), as follows:
+ The `MozSocial` interface and the `navigator.mozSocial` property which supports it have been removed.
+ The Social Bookmarks API has been removed.
+ The Social chat functionality has been removed.
+ The Social Status API has been removed.
+ All of the social widgets, except for the Share panel, have been removed. This includes the social sidebar, flyover panels, and so forth.
+ All supporting user interface features and functionality for the removed APIs have been removed as well.
+ Social service provider manifest properties supporting the removed functionality are no longer supported.
* If an add-on uses `mimeTypes.rdf` to provide a file extension to MIME type mapping, it must now register an entry in the `"ext-to-type-mapping"` category (Firefox bug 306471).
* The Browser API now includes a `detail` object on the event object of the `mozbrowserlocationchange` event that contains `canGoForward`/`canGoBack` properties, allowing retrieval of the mozBrowser's back/forward status synchronously (Firefox bug 1279635).
Older versions
--------------
* Firefox 50 for developers
* Firefox 49 for developers
* Firefox 48 for developers
* Firefox 47 for developers
* Firefox 46 for developers
* Firefox 45 for developers
* Firefox 44 for developers
* Firefox 43 for developers
* Firefox 42 for developers
* Firefox 41 for developers
* Firefox 40 for developers
* Firefox 39 for developers
* Firefox 38 for developers
* Firefox 37 for developers
* Firefox 36 for developers
* Firefox 35 for developers
* Firefox 34 for developers
* Firefox 33 for developers
* Firefox 32 for developers
* Firefox 31 for developers
* Firefox 30 for developers
* Firefox 29 for developers
* Firefox 28 for developers
* Firefox 27 for developers
* Firefox 26 for developers
* Firefox 25 for developers
* Firefox 24 for developers
* Firefox 23 for developers
* Firefox 22 for developers
* Firefox 21 for developers
* Firefox 20 for developers |
Firefox 60 for developers - Mozilla | Firefox 60 for developers
=========================
This article provides information about the changes in Firefox 60 that will affect developers. Firefox 60 was released on May 9, 2018.
Stylo comes to Firefox for Android in 60
----------------------------------------
Firefox's new parallel CSS engine — also known as **Quantum CSS** or **Stylo** — which was first enabled by default in Firefox 57 for desktop, has now been enabled in Firefox for Android.
Changes for web developers
--------------------------
### Developer tools
* In the CSS Pane rules view (see Examine and edit CSS), the keyboard shortcuts for precise value increments (increase/decrease by 0.1) have changed from `Alt` + `Up`/`Down` to `Ctrl` + `Up`/`Down` on Linux and Windows, to avoid clashes with default OS-level shortcuts (see Firefox bug 1413314).
* Also in the CSS Pane rules view, CSS variable names will now auto-complete (Firefox bug 1422635). If you enter `var(` into a property value and then type a dash (`-`), any variables you have declared in your CSS will then appear in an autocomplete list.
* In Responsive Design Mode, a *Reload when…* dropdown has been added to allow users to enable/disable automatic page reloads when touch simulation is toggled, or simulated user agent is changed. See Controlling page reload behavior for more details (Firefox bug 1428816).
* The `view_source.tab` preference has been removed so you can no longer toggle View Source mode between appearing in a new tab or new window. Page sources will always appear in new tabs from now on (Firefox bug 1418403).
### HTML
Pressing the Enter key in `designMode` and `contenteditable` now inserts `<div>` elements when the caret is in an inline element or text node which is a child of a block level editing host — instead of inserting `<br>` elements like it used to. If you want to use the old behavior on your app, you can do it with `document.execCommand()`. See Differences in markup generation for more details (also see Firefox bug 1430551).
### CSS
* The `align-content`, `align-items`, `align-self`, `justify-content`, and `place-content` property values have been updated as per the latest CSS Box Alignment Module Level 3 spec (Firefox bug 1430817).
* The `paint-order` property has been implemented (Firefox bug 1426146).
### SVG
*No changes.*
### JavaScript
* ECMAScript 2015 modules have been enabled by default in (Firefox bug 1438139). See ES6 In Depth: Modules and ES modules: A cartoon deep dive for more information, or consult MDN reference docs:
+ `<script src="main.js" type="module">` and `<script nomodule src="fallback.js">`
+ `import` and `export` statements.
* The `Array.prototype.values()` method has been added again (Firefox bug 1420101). Make sure your code doesn't have any custom implementation of this method.
### APIs
#### New APIs
* The Web Authentication API has been enabled in (Firefox bug 1432542).
#### DOM
* In the Web Authentication API, the `MakePublicKeyCredentialOptions` dictionary object has been renamed `PublicKeyCredentialCreationOptions`; this change has been made in Firefox (Firefox bug 1436473).
* The `dom.workers.enabled` pref has been removed, meaning workers can no longer be disabled since (Firefox bug 1434934).
* The `body` property is now implemented on the `Document` interface, rather than the `HTMLDocument` interface (Firefox bug 1276438).
* `PerformanceResourceTiming` is now available in workers (Firefox bug 1425458).
* The `PerformanceObserver.takeRecords()` method has been implemented (Firefox bug 1436692).
* The `KeyboardEvent.keyCode` attribute of punctuation key becomes non-zero even if the active keyboard layout doesn't produce ASCII characters. See these notes for more detail. Please do **not** use `KeyboardEvent.keyCode` in new applications — use `KeyboardEvent.key` or `KeyboardEvent.code` instead.
* The `Animation.updatePlaybackRate()` method has been implemented (Firefox bug 1436659).
* New rules have been included for determining keyCode values of punctuation keys (Firefox bug 1036008).
* The Gecko-only options object `storage` option of the `IDBFactory.open()` method (see Experimental Gecko options object) has been deprecated (Firefox bug 1442560).
* Promises can now be used within IndexedDB code (Firefox bug 1193394).
#### DOM events
*No changes.*
#### Service workers
*No changes.*
#### Media and WebRTC
* When recording or sharing media obtained using `getUserMedia()`, muting the camera by setting the corresponding track's `MediaStreamTrack.enabled` property to `false` now turns off the camera's "in use" indicator light, to help the user more easily see that the camera is not in use (Firefox bug 1299515). See User privacy for more details. See also this blog post.
* Removing a track from an `RTCPeerConnection` using `removeTrack()` no longer removes the track's `RTCRtpSender` from the peer connection's list of senders as reported by `getSenders()` (Firefox bug 1290949).
* The `RTCRtpContributingSource` and `RTCRtpSynchronizationSource` objects' timestamps were previously being reported based on values returned by `Date.getTime()`. In Firefox 60, these have been fixed to correctly use the Performance Timing API instead (Firefox bug 1433576).
* As per spec, the `ConvolverNode()` constructor now throws a `NotSupportedError` `DOMException` if the referenced `AudioBuffer` does not have 1, 2, or 4 channels (Firefox bug 1443228).
* The obsolete `RTCPeerConnection` event handler `RTCPeerConnection.onremovestream` has been removed; by now you should be using `removetrack` events instead (Firefox bug 1442385).
* The primary name for `RTCDataChannel` is now in fact `RTCDataChannel`, instead of being an alias for `DataChannel`. The name `DataChannel` is no longer supported (Firefox bug 1173851).
#### Canvas and WebGL
* If the `privacy.resistFingerprinting` preference is set to `true`, the `WEBGL_debug_renderer_info` WebGL extension will be disabled from now on (Firefox bug 1337157).
### CSSOM
*No changes.*
### HTTP
* `SameSite` cookies are now supported (Firefox bug 795346). See `Set-Cookie` for more information.
### Security
The `X-Content-Type-Options` header, when set to `no-sniff`, now follows the specification for JavaScript MIME types. In particular, `text/json` and `application/json` are no longer valid values (Firefox bug 1431095).
### Plugins
*No changes.*
### Other
Fetches that include credentials can now share connections with fetches that don't include credentials. For example, if the same origin requests some web fonts as well as some credentialed user data from the same CDN, both could share a connection, potentially leading to a quicker turnaround (Firefox bug 1363284).
Removals from the web platform
------------------------------
### HTML
*No changes.*
### CSS
* The proprietary `-moz-user-input` property's `enabled` and `disabled` values are no longer available (Firefox bug 1405087).
* The proprietary `-moz-border-top-colors`, `-moz-border-right-colors`, `-moz-border-bottom-colors`, and `-moz-border-left-colors` properties have been removed from the platform completely (Firefox bug 1429723).
### JavaScript
The non-standard expression closure syntax has been removed (Firefox bug 1426519).
### APIs
*No changes.*
### SVG
*No changes.*
### Other
*No changes.*
Changes for add-on and Mozilla developers
-----------------------------------------
### WebExtensions
Theme API:
* headerURL is now optional
* When creating a browser theme, any `text-shadow` applied to the header text is removed if no `headerURL` is specified (see Firefox bug 1404688).
* New properties are supported:
+ **tab\_line**
+ **tab\_selected**
+ **popup**
+ **popup\_border**
+ **popup\_text**
+ **tab\_loading**
+ **icons**
+ **icons\_attention**
+ **frame\_inactive**
+ **button\_background\_active**
+ **button\_background\_hover**
Older versions
--------------
* Firefox 59 for developers
* Firefox 58 for developers
* Firefox 57 for developers
* Firefox 56 for developers
* Firefox 55 for developers
* Firefox 54 for developers
* Firefox 53 for developers
* Firefox 52 for developers
* Firefox 51 for developers
* Firefox 50 for developers
* Firefox 49 for developers
* Firefox 48 for developers
* Firefox 47 for developers
* Firefox 46 for developers
* Firefox 45 for developers
* Firefox 44 for developers
* Firefox 43 for developers
* Firefox 42 for developers
* Firefox 41 for developers
* Firefox 40 for developers
* Firefox 39 for developers
* Firefox 38 for developers
* Firefox 37 for developers
* Firefox 36 for developers
* Firefox 35 for developers
* Firefox 34 for developers
* Firefox 33 for developers
* Firefox 32 for developers
* Firefox 31 for developers
* Firefox 30 for developers
* Firefox 29 for developers |
Firefox 89 for developers - Mozilla | Firefox 89 for developers
=========================
This article provides information about the changes in Firefox 89 that will affect developers. Firefox 89 was released on June 1, 2021.
**Note:** See also Looking fine with Firefox 89 on Mozilla Hacks.
Changes for web developers
--------------------------
### Developer Tools
*No changes.*
### HTML
*No changes.*
### CSS
* The `forced-colors` media feature has been implemented (Firefox bug 1659511).
* The `ascent-override`, `descent-override`, and `line-gap-override` `@font-face` descriptors have been implemented (Firefox bug 1681691 and Firefox bug 1704494).
* The `type()` function for `image/image-set()` has been implemented (Firefox bug 1695404).
* The `aspect-ratio` CSS property is now supported (Firefox bug 1672073).
### JavaScript
* Top-level `await` is now enabled by default (Firefox bug 1681046).
* ArrayBuffers can now be created with a length greater than 2GB-1 (up to 8GB) on 64-bit systems (Firefox bug 1703505).
### HTTP
*No changes.*
### APIs
#### DOM
* `PerformanceEventTiming` is now enabled by default (Firefox bug 1701029).
* The content of `<input>` and `<textarea>` elements can now be manipulated using `Document.execCommand()` commands by default, preserving edit history and providing parity with other browsers, without `contentEditable` or any lengthy workarounds required (Firefox bug 1220696).
#### Removals
* The following sensor events and their associated handlers have been removed (primarily for better compatibility with other major browser engines, and to address concerns related to privacy leaks):
+ `DeviceProximityEvent` and its event handler `window.ondeviceproximity` (Firefox bug 1699707).
+ `UserProximityEvent` and its event handler `window.onuserproximity`) (Firefox bug 1699707).
+ `DeviceLightEvent` and its event handler `window.ondevicelight` (Firefox bug 1701824).
### WebDriver conformance (Marionette)
#### Removals
* The `rotatable` capability that is not part of the WebDriver specification is no longer used (Firefox bug 1697630).
Changes for add-on developers
-----------------------------
* Dynamic JS module imports are now working in WebExtension content scripts (Firefox bug 1536094).
* Extension resources listed in web\_accessible\_resources can be loaded regardless of the request's CORS mode (Firefox bug 1694679).
* Firefox's UI has been redesigned, which affects usage of the `theme` API. The `tab_background_separator` and `toolbar_field_separator` properties are no longer supported. The `tab_line` and `toolbar_vertical_separator` will behave differently. For more information, see Changes to themeable areas of Firefox in version 89.
* The `pageAction` button can no longer be pinned or unpinned from the address bar, because the three-dot meatball menu is no longer visible by default (Firefox bug 1691454). As a result, the `pinned` property of the `page_action` manifest key no longer has any effect (Firefox bug 1703537).
* The "Remove from Address Bar" context menu item has been removed from the `pageAction` button (Firefox bug 1704474). For alternatives to this functionality, see Firefox bug 1712556.
Older versions
--------------
* Firefox 88 for developers
* Firefox 87 for developers
* Firefox 86 for developers
* Firefox 85 for developers
* Firefox 84 for developers
* Firefox 83 for developers
* Firefox 82 for developers
* Firefox 81 for developers
* Firefox 80 for developers
* Firefox 79 for developers
* Firefox 78 for developers
* Firefox 77 for developers
* Firefox 76 for developers
* Firefox 75 for developers
* Firefox 74 for developers
* Firefox 73 for developers
* Firefox 72 for developers
* Firefox 71 for developers
* Firefox 70 for developers
* Firefox 69 for developers
* Firefox 68 for developers
* Firefox 67 for developers
* Firefox 66 for developers
* Firefox 65 for developers
* Firefox 64 for developers
* Firefox 63 for developers
* Firefox 62 for developers
* Firefox 61 for developers
* Firefox 60 for developers
* Firefox 59 for developers
* Firefox 58 for developers |
Firefox 27 for developers - Mozilla | Firefox 27 for developers
=========================
Firefox 27 was released on February 4, 2014. This article lists key changes that are useful not only for web developers, but also Firefox and Gecko developers as well as add-on developers.
Changes for Web developers
--------------------------
### Developer Tools
* Breakpoints can now be set on DOM events.
* JavaScript in the debugger panel can be unminified, using the { } button.
* The inspector now has an "edit-element-html" feature, without needing an add-on.
* Background-URLs and colors have preview in inspector. Even hovering over canvas elements will give a pop-up with an image preview.
* Reflow logging has been added.
* Styles of SVG elements are now inspectable (Firefox bug 921191).
* Failure to find the image when clicking URL link in CSS inspector has been fixed (Firefox bug 921686).
* The `X-SourceMap` header is now supported (Firefox bug 765993).
More details in this post.
### CSS
* The `-moz-grab` and `-moz-grabbing` keywords on the CSS `cursor` property have been unprefixed to `grab` and `grabbing` (Firefox bug 880672).
* Support for the `-moz-hsla()` and `-moz-rgba()` functional notations has been dropped. Only the unprefixed versions, `hsla()` and `rgba()` are supported from now on (Firefox bug 893319).
* The "`true`" value for `text-align` has been added (Firefox bug 929991).
* Experimental support of `position:sticky` is now active by default on non-release builds (Firefox bug 902992). For releases builds, the `layout.css.sticky.enabled` preference still needs to be set to `true`.
* The `all` shorthand property has been added (Firefox bug 842329).
* The `unset` global value has been added; it allows to reset any CSS property (Firefox bug 921731).
* Curly braces are no longer allowed in HTML `style` attributes: doing `<div style="{ display: none }">` was working in quirks mode, but won't anymore Firefox bug 915053.
* The `overflow` property now works on `<fieldset>` (Firefox bug 261037).
### HTML
* The `color` value of the `<input>` `type` attribute has been implemented on desktop platforms. It was already available on mobile ones.
* The `allow-popups` directive is now supported with the `sandbox` attribute of the `<iframe>` element (Firefox bug 766282).
* Blending of HTML elements using the `mix-blend-mode` property has been implemented. The `layout.css.mix-blend-mode.enabled` preference must be set to `true` (Firefox bug 902525).
* The `typeMustMatch` property of the `<object>` element is now supported (Firefox bug 827160).
### JavaScript
ECMAScript 2015 implementation continues!
* The spread operator is now supported in Function calls (Firefox bug 762363).
* The mathematical function `Math.hypot()` has been implemented (Firefox bug 896264).
* The `yield*` expression is now implemented (Firefox bug 666396).
* The `MapIterator`, `SetIterator` and `ArrayIterator` objects now match the specification (Firefox bug 881226).
* for...of loops now expect the ES2015 standard iterator protocol moving away from SpiderMonkey old iterator protocol using `StopIteration`.
* `String.match` and `String.replace` now reset `RegExp.lastIndex` (Firefox bug 501739).
### Interfaces/APIs/DOM
* Support for the two `setRange()` methods on the `HTMLInputElement` interface has been added (Firefox bug 850364).
* Support for the two `setRange()` methods on the `HTMLTextAreaElement` interface has been added (Firefox bug 918940).
* The methods `getAllKeys()` and `openKeyCursor()` have been added to `IDBObjectStore` (Firefox bug 920633 and Firefox bug 920800).
* The `HTMLFormControlsCollection` interface has been implemented (Firefox bug 913920).
* The `CanvasRenderingContext2D` interface now supports the two methods `getLineDash()` and `setLineDash()` and the `lineDashOffset` property (Firefox bug 768067).
* The `typeMustMatch` attribute has been implemented on the `HTMLObjectElement` interface (Firefox bug 827160).
* The `copyFromChannel()` and `copyToChannel()` methods have been added to `AudioBuffer` (Firefox bug 915524).
* `Event.isTrusted()` is now unforgeable (Firefox bug 637248).
* The WebRTC API's `RTCIceCandidate` object now includes a `toJSON()` method to help with signaling and debugging (Firefox bug 928304).
* The `Navigator.vibrate()` method has been adapted to match the final specification: It now returns `false` when the list is too long or has too large entries, instead of throwing (Firefox bug 884935).
* As part of the ongoing effort to standardize global objects, the non-standard stylesheet change event interfaces, including `StyleRuleChangeEvent`, `StyleSheetApplicableStateChangeEvent` and `StyleSheetChangeEvent`, are no longer available from Web content. The `CSSGroupRuleRuleList` interface, the implementation detail of `CSSRuleList`, has also been removed (Firefox bug 872934 and Firefox bug 916871).
* `atob` now ignores whitespaces (Firefox bug 711180).
* WebGL: `MOZ_` prefixed extension strings are deprecated. Support for them will be removed in the future. Use unprefixed extension string only. To get draft extensions, set the `webgl.enable-draft-extensions` preferences (Firefox bug 924176).
### MathML
*No change.*
### SVG
* Blending of SVG elements using the `mix-blend-mode` property has been implemented. The `layout.css.mix-blend-mode.enabled` preference must be set to `true` (Firefox bug 902525).
Changes for addon and Mozilla developers
----------------------------------------
* The `downloads-indicator` button has gone away. You should now use the `downloads-button` element. If you need to check that it has loaded its overlay, check for the `indicator` attribute on that button.
* The `chrome://browser/skin/downloads/indicator.css` stylesheet is no longer referenced in Firefox.
Security
--------
* TLS 1.2 has been implemented for improved security (Firefox bug 861266).
See also
--------
* List of changes in Marionette for Firefox 27.
### Older versions
* Firefox 26 for developers
* Firefox 25 for developers
* Firefox 24 for developers
* Firefox 23 for developers
* Firefox 22 for developers
* Firefox 21 for developers
* Firefox 20 for developers
* Firefox 19 for developers
* Firefox 18 for developers
* Firefox 17 for developers
* Firefox 16 for developers
* Firefox 15 for developers
* Firefox 14 for developers
* Firefox 13 for developers
* Firefox 12 for developers
* Firefox 11 for developers
* Firefox 10 for developers
* Firefox 9 for developers
* Firefox 8 for developers
* Firefox 7 for developers
* Firefox 6 for developers
* Firefox 5 for developers
* Firefox 4 for developers
* Firefox 3.6 for developers
* Firefox 3.5 for developers
* Firefox 3 for developers
* Firefox 2 for developers
* Firefox 1.5 for developers |
Firefox 85 for developers - Mozilla | Firefox 85 for developers
=========================
This article provides information about the changes in Firefox 85 that will affect developers. Firefox 85 was released on January 26, 2021.
**Note:** See also January brings us Firefox 85 on Mozilla Hacks.
Changes for web developers
--------------------------
### Developer Tools
* Developers can now use the Page Inspector to toggle the `:focus-visible` pseudo-class for the currently selected element (in addition to the pseudo classes that were previously supported: `:hover`, `:active` and `:focus`, `:focus-within`, and `:visited`). (Firefox bug 1617608).
### HTML
* `<link rel="preload">` is now enabled. (Firefox bug 1626997).
#### Removals
* The `<menuitem>` HTML element is no longer available — it has been hidden behind the `dom.menuitem.enabled flag`. (Firefox bug 1680596).
### CSS
* The `:focus-visible` pseudo-class is now enabled. (Firefox bug 1445482).
* The `pinch-zoom` value for the `touch-action` property is now enabled. (Firefox bug 1329241).
### JavaScript
* The `collation` property can now be specified in the options passed to the `Intl.Collator()` constructor (Firefox bug 1670062). This allows developers to write code with greater clarity:
```js
// Old method
let pinyin = new Intl.Collator(["zh-u-co-pinyin"]);
// New method
let pinyin = new Intl.Collator("zh", { collation: "pinyin" });
```
### Plugins
* Flash support has been completely removed from Firefox (Firefox bug 1675349).
### APIs
*No changes.*
### WebDriver conformance (Marionette)
* Fixed a potential page load timeout situation when `WebDriver:ElementClick`
is called for a link with a `target` other than `_blank` (Firefox bug 1678455).
* Using web element references on browsing contexts other than the originating one now correctly returns a `no such element` error instead of a `stale element reference` error (Firefox bug 1684827).
#### Known bugs
* WebDriver commands following a call to `WebDriver:SwitchToFrame` can fail with a "no such window" error if the frame's content hasn't yet finished loading (Firefox bug 1691348).
* After a cross-group page navigation, accessing a previously-retrieved element might not always raise a "stale element" error, and can also lead to a "no such element" error. To prevent this, set the `marionette.actors.enabled` preference to `false` (Firefox bug 1690308).
Changes for add-on developers
-----------------------------
*No changes.*
Older versions
--------------
* Firefox 84 for developers
* Firefox 83 for developers
* Firefox 82 for developers
* Firefox 81 for developers
* Firefox 80 for developers
* Firefox 79 for developers
* Firefox 78 for developers
* Firefox 77 for developers
* Firefox 76 for developers
* Firefox 75 for developers
* Firefox 74 for developers
* Firefox 73 for developers
* Firefox 72 for developers
* Firefox 71 for developers
* Firefox 70 for developers
* Firefox 69 for developers
* Firefox 68 for developers
* Firefox 67 for developers
* Firefox 66 for developers
* Firefox 65 for developers
* Firefox 64 for developers
* Firefox 63 for developers
* Firefox 62 for developers
* Firefox 61 for developers
* Firefox 60 for developers
* Firefox 59 for developers
* Firefox 58 for developers
* Firefox 57 for developers
* Firefox 56 for developers
* Firefox 55 for developers
* Firefox 54 for developers |
Firefox 117 for developers - Mozilla | Firefox 117 for developers
==========================
This article provides information about the changes in Firefox 117 that affect developers. Firefox 117 was released on August 29, 2023.
Changes for web developers
--------------------------
### HTML
No notable changes.
### CSS
* The CSS Nesting module is now supported in Firefox, along with the `&` nesting selector. This allows developers to write nested CSS, which helps with the readability, modularity, and maintainability of CSS stylesheets. It also potentially helps reduce CSS file size, decreasing download sizes. (Firefox bug 1835066, Firefox bug 1840781)
* The `math-style` and `math-depth` properties are now supported, as well as the `math` value for the `font-size` property (Firefox bug 1845516).
* The `contain-intrinsic-size: auto none` syntax is now supported, which allows for using the last-remembered size of an element if possible and falls back to `contain-intrinsic-size: none` otherwise.
This is useful for grid and multi-column layouts to allow elements to be laid out as though they have no contents instead of 0px height (Firefox bug 1835813).
### JavaScript
No notable changes.
### SVG
* Inline SVGs now support `<script>` elements with `type="module"`, `defer`, and `async` attributes.
This allows SVGs to use modern JavaScript features, including ES modules, and to load scripts asynchronously (Firefox bug 1839954).
### HTTP
* Fixed a bug where the Content-Security-Policy `'strict-dynamic'` source expression was not being enforced in `default-src` directives.
The behavior now matches the specification where `default-src` directive values are used as a fallback when `script-src` is not provided (Firefox bug 1313937).
* The `Range` header is now a CORS-safelisted request header when the value is a single byte range (e.g., `bytes=100-200`).
This allows the `Range` header to be used in cross-origin requests without triggering a preflight request, which is useful for requesting media and resuming downloads (Firefox bug 1733981).
### APIs
* The `CanvasRenderingContext2D.getContextAttributes()` method can now be used to get the 2D context attributes being used by the browser (Firefox bug 1517786).
* The `ReadableStream.from()` static member is now supported, allowing developers to construct a readable stream from any iterable or async iterable object (Firefox bug 1772772).
* WebRTC Encoded Transforms are now supported, allowing web applications to modify incoming and outgoing WebRTC encoded video and audio frames using a `TransformStream` running in a worker.
The supported interfaces include: `RTCRtpScriptTransform`, `RTCRtpScriptTransformer`, `RTCRtpSender.transform`, `RTCRtpReceiver.transform`, `RTCEncodedVideoFrame`, and `RTCEncodedAudioFrame`, and the `RTCTransformEvent` and worker `rtctransform` event (Firefox bug 1631263).
* `CSSStyleRule` now inherits from `CSSGroupingRule` instead of directly from `CSSRule`. As a result, it additionally implements the property `cssRules` and the methods `deleteRule()` and `insertRule()` (Firefox bug 1846251).
### WebDriver conformance (WebDriver BiDi, Marionette)
#### WebDriver BiDi
* Added the `browser.close` command that allows users to terminate all WebDriver sessions and close the browser (Firefox bug 1829334).
* Added the `browsingContext.setViewport` command that allows users to change the dimensions of a top level browsing context (Firefox bug 1838664).
* Added the `browsingContext.fragmentNavigated` event which is emitted for same-document navigations (Firefox bug 1841039).
* Added support for the `background` argument of the `browsingContext.create` command, which will force the new context to be created in the background. This argument is optional and defaults to `false`, meaning that `browsingContext.create` now opens new contexts in the foreground by default (Firefox bug 1843507).
* Added support for the `clip` argument of the `browsingContext.captureScreenshot` command, which allows to restrict the screenshot either to a specific area or to an element. When clipping to an element, you can optionally scroll the element into view before taking the screenshot (Firefox bug 1840998).
* All commands and events related to a navigation will now provide a `navigation` id, which is a `UUID` identifying a specific navigation. This property is available in the `browsingContext.navigate` response, in the `browsingContext.load`, `browsingContext.domContentLoaded`, `browsingContext.fragmentNavigated` events, as well as in all `network` events created for a navigation request (Firefox bug 1763122, Firefox bug 1789484, Firefox bug 1805405).
* `headers` and `cookies` in `network` events are now serialized as `network.BytesValue`, which will provide a better support for non-UTF8 values (Firefox bug 1842619).
* The `browsingContext.create` command will now wait until the created context has a valid size (Firefox bug 1847044).
### Developer tools
* The Network Monitor now shows information about proxied requests, including the proxy address, the proxy status, and the proxy HTTP version in the Headers tab (Firefox bug 1707192).
* The area selected by the Measuring Tool can now be resized and moved using keyboard shortcuts.
Pressing the arrow keys moves the selected area, while pressing `Ctrl` + arrow keys (or `Cmd` + arrow keys on a Mac) resizes the selected area.
Holding down the `Shift` key accelerates the moving and resizing actions when using these key combinations (Firefox bug 1262782).
* Properties that are not supported in highlight pseudo-elements (`::highlight()`, `::target-text`, `::spelling-error`, `::grammar-error`, and `::selection`) are now reported in the Page Inspector CSS rules panel (Firefox bug 1842157).
Changes for add-on developers
-----------------------------
No notable changes.
Older versions
--------------
* Firefox 116 for developers
* Firefox 115 for developers
* Firefox 114 for developers
* Firefox 113 for developers
* Firefox 112 for developers
* Firefox 111 for developers
* Firefox 110 for developers
* Firefox 109 for developers
* Firefox 108 for developers
* Firefox 107 for developers
* Firefox 106 for developers
* Firefox 105 for developers
* Firefox 104 for developers
* Firefox 103 for developers
* Firefox 102 for developers
* Firefox 101 for developers
* Firefox 100 for developers
* Firefox 99 for developers
* Firefox 98 for developers
* Firefox 97 for developers
* Firefox 96 for developers
* Firefox 95 for developers
* Firefox 94 for developers
* Firefox 93 for developers
* Firefox 92 for developers
* Firefox 91 for developers
* Firefox 90 for developers
* Firefox 89 for developers
* Firefox 88 for developers
* Firefox 87 for developers
* Firefox 86 for developers |
Firefox 16 for developers - Mozilla | Firefox 16 for developers
=========================
Firefox 16 shipped on October 9, 2012. This article lists key changes that are useful for not only Web developers to know about, but also Firefox and Gecko developers as well as add-on developers.
Changes for Web developers
--------------------------
### HTML
* The `<meter>` element is now supported.
* Support for the HTML Microdata API has been added. (bug 591467)
* `<canvas>` now supports the CSS `currentcolor` in all case. (Firefox bug 629882)
* `<input>` now allows filtering based on arbitrary mimetypes in `accept` (Firefox bug 565274).
* Two new attributes, `width` and `height` have been added to the `<input>` element (bug 683855).
### CSS
* Support for the standard, unprefixed version of CSS Animations has been landed (bug 762302).
* Support for reverse animation direction (keywords `reverse` and `alternate-reverse` on the `animation-direction` property) has been added. (bug 655920).
* You can now animate the CSS `height` and `width` properties.
* The `animation-duration` and `transition-duration` CSS properties now reject negative values (and do not handle them as `0s` anymore) (bug 773102).
* Support for the standard, unprefixed version of CSS Transforms has been landed (bug 745523). `<length>` cannot be used for translation values in `matrix()` and `matrix3d()` anymore (Firefox bug 719054).
* Support for the standard, unprefixed version of CSS Gradients has been landed. Note that the syntax has changed significantly since the prefixed version, so you should read up on this (bug 752187).
* The `-moz-box-sizing` implementation has been updated to apply to table cells too (bug 338554).
* Support for the standard, unprefixed version of `calc()` has been landed (bug 771678).
* The `<resolution>` CSS data type has been extended to support the `dppx` (bug 741644).
* On screen, for media queries, `dppx`, `dpi`, and `dpcm` are now representing values based on CSS pixels and no more with the physical units (bug 771390).
* Three new pseudo-classes `:-moz-meter-optimum`, `:-moz-meter-sub-optimum`, and `:-moz-meter-sub-sub-optimum` have been added for accessing/styling a `<meter>` element in a particular state (bug 660238).
* The `appearance` property gains two new values: `meterbar` and `meterchunk`. They represent components inside the `<meter>` element (bug 659999).
* The `min-width` and `min-height` now supports the `auto` keyword for flex items (and resolves to `0` for other items) (Firefox bug 763689).
### API/DOM
* Two new properties `width` and `height` have been added to the `HTMLInputElement` interface (bug 683855).
* IndexedDB properties and methods have been unprefixed. (bug 726378)
* The Battery API is now unprefixed.
* The Vibration API has been unprefixed.
* The non-standard `Keyboard` interface, prefixed as `mozKeyboard`, now has the `Keyboard.setSelectedOption()` and `Keyboard.setValue()` methods, as well as the `Keyboard.onfocuschange`. *This interface, only available for Firefox OS, has been removed in Firefox 31.*
* The `java` and `Packages` global objects have been removed. See LiveConnect.
* The `CSSRule.type` associated with `CSSNamespaceRule` has been updated from `UNKNOWN_RULE` (`0`) to `NAMESPACE_RULE` (`10`) (bug 765590).
* WebSMS API: `SmsRequest` has been superseded by the more general `DOMRequest`.
* The non-standard `Element.scrollTopMax` and `Element.scrollLeftMax` read-only properties have been added (Firefox bug 766937).
* The second parameter of `Blob()`, when set to `null` or `undefined`, is now being handled as an empty dictionary (Firefox bug 7691119).
### JavaScript
* `Number` objects now offer `isFinite()`, `toInteger()`, and `isInteger()` methods. (bug 761480, bug 761495)
* The Harmony spread operator is now supported in `Array` initializers (bug 574130). Note it is not yet supported in calls (bug 762363).
* The experimental `TypedArray.prototype.move()` method has been added (available in Aurora and Nightly channels only) (Firefox bug 730873).
### WebGL
*No change.*
### SVG
*No change.*
### MathML
* The `lspace` and `rspace` attributes of `<mo>` now correctly default to `thickmathspace`.
### Network
### Developer tools
* There's now a handy developer toolbar you can access by going to Tools > Web Developer > Developer Toolbar, or by pressing Ctrl-Shift-V (Cmd-Opt-V on Mac OS X). This toolbar offers a command line interface as well as buttons for quickly accessing useful tools. The graphical command line interface *GCLI* is easy to expand and additional commands are expected in the future. Type "help" to get a list of supported commands.
* The Web Console now displays an error count so you can quickly see how much work you have ahead of you.
* The Scratchpad now offers a list of recently opened files.
Changes for Open Web App developers
-----------------------------------
* Initial Open Web App support has been implemented in the desktop versions of Firefox (that is, on Windows, Mac OS X, and Linux).
Changes for add-on and Mozilla developers
-----------------------------------------
### Interface changes
`nsIPrivateDOMEvent` has been merged into `nsIDOMEvent`. (Firefox bug 761613)
#### New interfaces
#### Removed interfaces
The following interfaces have been removed. |
Firefox 6 for developers - Mozilla | Firefox 6 for developers
========================
Firefox 6, based on Gecko 6.0, was released on August 16, 2011. This article provides links to information about the changes that affect developers in this release.
Changes for web developers
--------------------------
### HTML
* The HTML5 `<progress>` element, which lets you create a progress bar, is now supported.
* The parsing of the HTML5 `<track>` element, which specifies text tracks for media elements, is now supported. This element should appear in the DOM now, though its behavior is still not implemented.
* The `<iframe>` element is now clipped correctly by its container when the container's corners have been rounded using the `border-radius` property.
* `<form>` elements' text `<input>` fields no longer support the XUL `maxwidth` property; this was never intentional, and is in violation of the HTML specification. You should instead use the `size` attribute to set the maximum width of input fields.
* The `<canvas>` `CanvasRenderingContext2d` properties `fillStyle` and `strokeStyle` used to ignore garbage included after a valid color definition; now this is correctly treated as an error. For example, "red blue" as a color used to be treated as "red", when it should have been ignored.
* The width and height of `<canvas>` elements can now properly be set to 0px; previously, these were getting arbitrarily set to 300px when you tried to do that.
* Support for the HTML custom data attributes (`data-*`) has been added. The DOM `element.dataset` property allows to access them.
* When a `<textarea>` element receives focus, the text insertion point is now placed, by default, at the beginning of the text rather than at the end. This makes Firefox's behavior consistent with other browsers.
### CSS
`-moz-text-decoration-color`
This new property lets you set the color used by text decorations, such as underlines, overlines, and strikethroughs.
`-moz-text-decoration-line`
This new property lets you set the kind of text decorations added to an element.
`-moz-text-decoration-style`
This new property lets you set the style of text decorations, such as underlines, overlines, and strikethroughs. Styles include single-strokes, double strokes, wavy lines, dotted lines, and so forth.
`-moz-hyphens`
This new property lets you control how hyphenation of words during line wrapping is handled.
`-moz-orient`
A new (currently Mozilla-specific) property which lets you control the vertical or horizontal orientation of certain elements (particularly `<progress>`).
`::-moz-progress-bar`
A Mozilla-specific pseudo-element that lets you style the area of an `<progress>` element representing the completed portion of a task.
#### Other changes
* The `@-moz-document` property has a new `regexp()` function, which lets you match the document's URL to a regular expression.
* The `azimuth` CSS property is no longer supported, as we have removed what little code we had for the `aural` media group. It was never significantly implemented, so it made more sense to remove the crufty implementation for the time being rather than try to patch it up.
* In the past, the `:hover` pseudoclass was not applied to class selectors when in quirks mode; for example, `.someclass:hover` did not work. This quirk has been removed.
* The `:indeterminate` pseudo-class can be applied to `<progress>` elements. This is non-standard, but we hope it will be adopted by other browsers, because it will be useful.
* The `-moz-win-exclude-glass` value has been added to the `-moz-appearance` CSS property in order to exclude opaque regions in Aero Glass glaze effects on Windows systems.
* Firefox bug 658949 changed how the hash (#) symbol is treated in data URLs which may break CSS stylesheets which contain such a symbol if it is not escaped.
### DOM
Using media queries from code
You can now test the result of a media query string programmatically using the `window.matchMedia()` method and the `MediaQueryList` interface.
Touch events
Firefox 6 adds support for W3C standard touch events; these make it easy to interpret one or more touches at a time on touch-sensitive surfaces such as touch screens and trackpads.
Server-sent events
Server-sent events make it possible for a web application to ask a server to send events just like any locally-created DOM event.
* `navigator.securityPolicy`, which has returned an empty string for a long time, has been removed outright.
* `BlobBuilder` is now implemented, although for now it's prefixed (so you need to use `MozBlobBuilder`).
* The `Document.height` and `Document.width` have been removed. Firefox bug 585877
* The `DocumentType` object's `entities` and `notations` properties, which were never implemented and always returned `null`, have been removed, since they've been removed from the specification anyway.
* The `DOMConfiguration` interface and the `document.domConfig` property that used it have both been removed; they were never supported and have since been removed from the DOM specification.
* The `hashchange` event now correctly includes the `newURL` and `oldURL` fields.
* The `FileReader` interface's `abort()` method now throws an exception when used if no file read is in progress.
* The `window.postMessage()` method now uses the structured clone algorithm to let you pass JavaScript objects instead of just strings from one window to another.
* The `window.history` API now uses the structured clone algorithm to serialize the objects you pass to the `pushState()` and `replaceState()` methods; this lets you use more complex objects (including those that contain cyclic graphs of references).
* You can now detect when printing has been initiated and has completed by listening for the new `beforeprint` and `afterprint` events.
* The `document.strictErrorChecking` property has been removed, since it was never implemented and was removed from the DOM specification.
* The standard `event.defaultPrevented` property is now supported; you should use this instead of the non-standard `getPreventDefault()` method to detect whether or not `event.preventDefault()` was called on the event.
* The `window.top` property is now properly read only.
* DOM views, which we never documented, have been removed. This was a bit of implementation detail that was unnecessarily complicating things, so we got rid of it. If you notice this change, you're probably doing something wrong.
* The `EventTarget` function `addEventListener()`'s `useCapture` parameter is now optional, as it is in WebKit (and as per the latest version of the specification).
* The `mozResponseArrayBuffer` property of the `XMLHttpRequest` object has been replaced with the `responseType` and `response` properties.
* The `element.dataset` property has been added to the `HTMLElement` interface allowing access to the `data-*` global attributes of an element.
* The `CustomEvent` interface has been implemented. (see Firefox bug 427537)
* For security reasons, `data:` and `javascript:` URLs no longer inherit the security context of the current page when the user enters them in the location bar; instead, a new, empty, security context is created. This means that script loaded by entering `javascript:` URLs in the location bar no longer has access to DOM methods and the like, for example. These URLs continue to work as before when used by script, however.
### JavaScript
* In the past, it was possible to use the `new` operator on several built-in functions (`eval()`, `parseInt()`, `Date.parse()`, …) that should not have allowed it, according to the specification. This behavior is no longer supported. Using the `new` operator in this way was never officially supported and was not widely done, so it's unlikely that this change affects you.
* ECMAScript 2015 WeakMaps have been added as a prototype implementation.
### SVG
* The `pathLength` attribute is now supported.
* SVG patterns, gradients, and filters now work correctly when loaded from `data:` URLs.
### MathML
* The implementation of `<mstyle>` has been corrected.
### Accessibility (ARIA)
* A state change event is now correctly sent when the value of `aria-busy` changes.
* An attribute change event is now correctly sent when `aria-sort` occurs.
### Networking
WebSockets
WebSockets was updated to protocol version 07 for Firefox 6. In addition, the global `WebSocket` object has been renamed to `MozWebSocket` to prevent it from incorrectly being used to detect the availability of unprefixed WebSockets.
* Parsing of the `Content-Disposition` header has been fixed to properly interpret backslash-escaped ASCII characters as just that character itself. Previously it was incorrectly replacing that character with an underscore ("\_").
* The value of the path field on `Set-Cookie` headers is now interpreted correctly when quotes are used; previously, they were being treated as part of the path string instead of as delimiters. **This change may affect compatibility with some websites**, so authors should check their code.
* The `Upgrade` request header is now supported; you can request an upgrade of an HTTP channel to another protocol by calling `nsIHttpChannelInternal.HTTPUpgrade()`.
### Other changes
* Support for microsummaries has been removed; these were never widely used, were not very discoverable, and continuing to support them was making improvements to the Places (bookmark and history) architecture difficult.
* WebGL now supports the `OES_texture_float` extension.
* The new *Scratchpad* tool provides a handy place to experiment with JavaScript code.
* The `console.trace()` method has been added to the Console API (Firefox bug 585956).
Changes for Mozilla and add-on developers
-----------------------------------------
For an overview of the changes you may need to make in order to make your add-on compatible with Firefox 6, see Updating add-ons for Firefox 6.
**Note:** Firefox 6 requires that binary components be recompiled, as do all major releases of Firefox. See Binary Interfaces for details.
### JavaScript code modules
#### FileUtils.jsm
* The `openSafeFileOutputStream()` method now opens files with the `DEFER_OPEN` behavior flag instead of attempting to open them immediately.
#### XPCOMUtils.jsm
* The new `importRelative()` method lets you load one JavaScript code module from a path relative to the path of another JavaScript code module. This makes it easier to build modules that depend on each other.
### XPCOM
* `nsCOMArray<T>` now has a `RemoveObjectsAt()` method for removing multiple objects at once from the array.
### Using the DOM from chrome
Using the DOM File API in chrome code
Although you've always been able to use the DOM File API from chrome code, the `File` constructor now supports specifying a local pathname string when used from chrome. In addition, you can also specify the file to access using the DOM File API using an `nsIFile` object.
### Interface changes
* `nsINavHistoryQueryOptions` now supports sorting in frequency order using the new `SORT_BY_FREQUENCY_ASCENDING` and `SORT_BY_FREQUENCY_DESCENDING` constants.
* `nsIFilePicker` has a new `nsIFilePicker.addToRecentDocs` attribute, which lets you indicate that the selected file should be added to the user's "recent documents" list if there is one. This attribute has no effect when in private browsing mode.
* `nsINavBookmarkObserver` methods with item ID parameters now require a GUID as well.
* `nsIPrefBranch.clearUserPref()` no longer throws an exception if the specified preference doesn't exist or has no user-set value. Instead, it does nothing.
* The `nsIMemoryReporter` interface now provides support for indicating the kind of memory being described (mapped, heap, or other).
* The `stateData` attribute of `nsISHEntry` now returns a `nsIStructuredCloneContainer`.
* `nsIURI` has a new `nsIURI.ref` attribute, which returns the reference portion (the part after the "#") of the URI. It also has new methods `nsIURI.cloneIgnoringRef()` which clones the `nsIURI` without the ref member and `nsIURI.equalsExceptRef()` which compares to another `nsIURI` ignoring the ref member.
#### New interfaces
`mozIAsyncFavicons`
A new service that lets you access the favicon service asynchronously.
`nsIEventSource`
*Details forthcoming.*
`nsIGSettingsCollection`
*Details forthcoming.*
`nsIGSettingsService`
*Details forthcoming.*
`nsIHttpUpgradeListener`
The callback interface for handling HTTP upgrade requests via the `nsIHttpChannelInternal.HTTPUpgrade()` method.
`nsIStructuredCloneContainer`
A container for objects that have been serialized using the structured clone algorithm.
`nsITelemetry`
Implements telemetry support to allow recording of telemetry data to be used to present histograms for performance tracking purposes. See Firefox bug 649502 and Firefox bug 585196.
`nsITimedChannel`
See Firefox bug 576006.
`nsIWebSocketListener`
See Firefox bug 640003.
`nsIWebSocketProtocol`
See Firefox bug 640003.
#### Removed interfaces
The following interfaces were implementation details that are no longer needed:
* `nsIDOMDocumentEvent` (see Firefox bug 655517)
* `nsIDOMDocumentTraversal` (see Firefox bug 655514)
* `nsIDOMDocumentRange` (see Firefox bug 655513)
* `IWeaveCrypto` (see Firefox bug 651596)
* `nsIDOM3DocumentEvent` (see Firefox bug 481863)
* `nsIDOMAbstractView`
* `nsILiveTitleNotificationSubject`
* `nsIPlugin` (see Firefox bug 637253)
* `nsIPluginInstance` (see Firefox bug 637253)
* `nsIHTMLEditRules` (see Firefox bug 633750)
* `nsIXSLTProcessorObsolete` (see Firefox bug 649534)
### Other changes
Using preferences from application code
A new static API is available for easily accessing preferences; this is only available to application code and can't be used by add-ons.
See also
--------
* Firefox 5 for developers
* Firefox 4 for developers
* Firefox 3.6 for developers
* Firefox 3.5 for developers
* Firefox 3 for developers
* Firefox 2 for developers
* Firefox 1.5 for developers |
Firefox 74 for developers - Mozilla | Firefox 74 for developers
=========================
This article provides information about the changes in Firefox 74 that will affect developers. Firefox 74 was released on March 10, 2020.
Changes for web developers
--------------------------
### Developer tools
#### Web console
* The `$x()` web console helper's third argument (result type) now accepts simple string values as well as `XPathResult` constants (bug 1602591).
* Freshly landed support for the optional chaining operator "?." which can also be used with Console's autocomplete (bug 1594009).
* The Debugger can now inspect and debug nested workers (bug 1590766)
### HTML
*No changes.*
### CSS
* `text-underline-position` is now enabled by default (bug 1606997).
* The `text-underline-offset` and `text-decoration-thickness` properties now accept percentage values (bug 1607534).
* The `auto` value of the `outline-style` property has been enabled by default (Firefox bug 1031664).
#### Removals
* The `-moz-` prefixed-Multiple-column layout properties have been removed (Firefox bug 1308636).
### SVG
*No changes.*
### JavaScript
* The Optional chaining operator has been implemented (Firefox bug 1566143).
* When a JavaScript URL (`javascript:`) is evaluated and the result is a string, this string is parsed to create an HTML document, which is then presented. Previously, this document's URL (as reported by the `document.location` property, for example) was the originating `javascript:` URL; it is now correctly the URL of the document the `javascript:` URL was evaluated in (Firefox bug 836567).
#### Removals
* The `Object.toSource()` method and the global function `uneval()` are no longer available for use by web content or extensions (bug 1565170).
### APIs
#### DOM
* The `IDBTransaction.commit()` method has been implemented (Firefox bug 1497007).
#### DOM events
* Firefox 74 now supports the `languagechange_event` event and its companion event handler property, `onlanguagechange`, which is triggered when the user changes their preferred language (Firefox bug 1154779). This was previously listed in our compatibility database as supported from Firefox 3.5, but this was in error.
#### Canvas and WebGL
* The `TextMetrics` interface has been extended to contain four more properties measuring the actual bounding box — `actualBoundingBoxLeft`, `actualBoundingBoxRight`, `actualBoundingBoxAscent`, and `actualBoundingBoxDescent`. Text metrics can be retrieved using the `CanvasRenderingContext2D.measureText()` method (Firefox bug 1102584).
#### Removals
* The non-standard `IDBDatabase.mozCreateFileHandle()` method has been removed, in favor of the (also non-standard) `IDBDatabase.createMutableFile()` method (Firefox bug 1024312).
* The non-standard `IDBMutableFile.getFile()` method has been removed (Firefox bug 1607791).
* The non-standard `HTMLCanvasElement` method `mozGetAsFile()` has been removed, after being deprecated several years ago (Firefox bug 1588980).
* The `FetchEvent` property `isReload` has been removed, from both Firefox and the specification (Firefox bug 1264175).
### HTTP
* The `Cross-Origin-Resource-Policy` header is now enabled by default (bug 1602363).
### Security
* TLS 1.0 and 1.1 support has been removed from Firefox; you'll need to make sure your web server supports TLS 1.2 or 1.3 going forward. From now on, Firefox will return a Secure Connection Failed error when connecting to servers using the older TLS versions (Firefox bug 1606734).
* Starting in Firefox 74, when a site delegates permission to access a resource to embedded content in an `<iframe>` using the `allow` attribute, and the embedded page requests permission to use that resource, the parent page prompts the user for permission to use the resource and share it with the embedded domain, rather than both the outer and inner pages prompting the user for permission. If the outer page doesn't have the permission requested by the `allow` attribute, the `<iframe>` is immediately denied access without prompting the user Firefox bug 1483631.
### Plugins
*No changes.*
### WebDriver conformance (Marionette)
* Added `WebDriver:Print` to print the current page as a PDF document (Firefox bug 1604506).
* `Webdriver:TakeScreenshot` now always captures the top-level browsing context and not the currently-selected browsing context, if no element to capture has been specified (Firefox bug 1398087, Firefox bug 1606794).
* Using `Webdriver:TakeScreenshot`'s `full` argument causes the complete page to be captured (Firefox bug 1571424).
Changes for add-on developers
-----------------------------
### API changes
* Shortcut keys can now be unassigned in `Commands.update` by passing an empty value of `shortcut` Firefox bug 1475043.
* `urlclassification`s are now returned as part of the `details` in each event of `webrequest`, providing information on whether a request is classified as fingerprinting or tracking Firefox bug 1589494.
### Manifest changes
*No changes.*
See also
--------
* Hacks blog post: Security means more with Firefox 74
Older versions
--------------
* Firefox 73 for developers
* Firefox 72 for developers
* Firefox 71 for developers
* Firefox 70 for developers
* Firefox 69 for developers
* Firefox 68 for developers
* Firefox 67 for developers
* Firefox 66 for developers
* Firefox 65 for developers
* Firefox 64 for developers
* Firefox 63 for developers
* Firefox 62 for developers
* Firefox 61 for developers
* Firefox 60 for developers
* Firefox 59 for developers
* Firefox 58 for developers
* Firefox 57 for developers
* Firefox 56 for developers
* Firefox 55 for developers
* Firefox 54 for developers
* Firefox 53 for developers
* Firefox 52 for developers
* Firefox 51 for developers
* Firefox 50 for developers
* Firefox 49 for developers
* Firefox 48 for developers
* Firefox 47 for developers
* Firefox 46 for developers
* Firefox 45 for developers
* Firefox 44 for developers
* Firefox 43 for developers |
Firefox 45 for developers - Mozilla | Firefox 45 for developers
=========================
To test the latest developer features of Firefox, install Firefox Developer Edition Firefox 45 was released on March 8, 2016. This article lists key changes that are useful not only for web developers, but also Firefox and Gecko developers as well as add-on developers.
Changes for Web developers
--------------------------
### Developer Tools
Highlights:
* Full-text search in the Page Inspector
* Heap snapshot diffing in the Memory tool
* DomContentLoaded and load events shown in the Network Monitor
* Animation inspector improvements
All devtools bugs fixed between Firefox 43 and Firefox 44.
### HTML
* Content Security Policy can now be set directly on the `<meta>` element (Firefox bug 663570).
* The attribute `referrer` has been renamed `referrerpolicy` on `<img>`, `<area>`, `<a>`, and `<iframe>` (Firefox bug 1187357).
* Changes in the viewport, or a resize, now trigger the reselection of responsive images for `<img srcset>` (Firefox bug 1166138).
### CSS
* `word-spacing` now allows percentage values (Firefox bug 1038663).
* Our implementation of CSS Grids has been improved and is no more considered experimental; it is now activated by default in nightly and developer edition, but not for beta and release (Firefox bug 1000592):
+ Gutters, that is the `grid-column-gap`, `grid-row-gap`, and `grid-gap` properties are now supported (Firefox bug 1176792).
+ The implied minimum size of grid Items, that is the special `min-width` and `min-height` `auto` behavior has been implemented (Firefox bug 1176775).
+ `align-self` and `justify-self` are now supported on grid layouts (Firefox bug 1151213).
+ `align-content` and `justify-content` are now supported on grid layouts (Firefox bug 1151214).
+ Resolved value of grid-template-columns,grid-template-rows in px units (Firefox bug 978212).
+ The related feature `display`: contents has been supported since Firefox 37
* Implement full support for CSS Box Alignment for CSS Grid, support the missing values: `start`, `end`, `self-start`, `self-end`, `left`, `right`, `last-baseline`, `space-evenly` (Firefox bug 1176782). CSS Box Alignment currently applies only to CSS Flexbox and CSS Grid.
* [css-grid][css-flexbox] Implement grid/flex layout for <fieldset> (Firefox bug 1230207).
* The `inline-start` and `inline-end` values have been added to `float` and `clear` (Firefox bug 1122918). They are enabled by default on Nightly and Aurora (Dev edition), as well as on Firefox OS; to activate it on a release or beta version, you need to flip the `layout.css.float-logical-values.enabled` to `true`.
* The `text-emphasis`, `text-emphasis-style`, `text-emphasis-color`, and `text-emphasis-position` have been implemented; they are disabled by default (set `layout.css.text-emphasis.enabled` to true to activate them (Firefox bug 1040668).
* Several `-webkit` prefixed properties and values have been added for web compatibility, behind the preference `layout.css.prefixes.webkit`, defaulting to `false`:
+ Added `-webkit-backface-visibility`, `-webkit-perspective` and `-webkit-perspective-origin` for web compatibility, behind the preference `layout.css.prefixes.webkit`, defaulting to `false` (Firefox bug 1179444).
### JavaScript
* ES2015 Classes are now enabled by default (Firefox bug 1197932).
* Expression closures are deprecated and will now present a warning in the console (Firefox bug 995610).
* `String.prototype.replace` does not restore RegExp static properties after executing function parameter anymore (Firefox bug 1226936).
* `Math.random()` has been updated to the better XorShift128+ algorithm (Firefox bug 322529).
### Interfaces/APIs/DOM
#### DOM & HTML DOM
* For compatibility, the non-standard property `Node.innerText` has been implemented (Firefox bug 264412).
* The `HTMLImageElement.srcset` attribute now reacts to resize/viewport changes (Firefox bug 1166138).
* `Element.getAttributeNames()` has been implemented (Firefox bug 1228634).
#### WebGL
Our implementation of WebGL 2 has been extended:
* Support of programs and shaders has been added (Firefox bug 1048743).
* Support for uniforms and attributes has been added (Firefox bug 1048745).
* Framebuffer objects have been implemented (Firefox bug 1048732).
* Renderbuffer objects have been implemented (Firefox bug 1048733).
#### IndexedDB
*No change.*
#### Service Workers
* `Clients.get()` and `FetchEvent.clientId` have been implemented (Firefox bug 1222464.)
* `Clients.openWindow()` has been implemented (Firefox bug 1172870.)
* The options object that can be passed as a parameter when invoking `Clients.matchAll()` can now include an `includeUncontrolled` property. This is a boolean value — if set to `true`, the matching operation will return all service worker clients who share the same origin as the current service worker. Otherwise, it returns only the service worker clients controlled by the current service worker. The default is `false`.
#### WebRTC
*No change.*
#### New APIs
*No change.*
#### Miscellaneous
* Web Speech Synthesis API has been implemented on Firefox Desktop (Firefox bug 1003439).
* The `storage` event has been added.
* The interface `ComputedTiming` have been added to our experimental implementation of Web Animations API (Firefox bug 1108055).
* The `Document.onselectionchange` event handler property has been added (Firefox bug 1231193).
* After removing a video track from a media stream by calling `MediaStream.removeTrack()` you can now add another video track later using `MediaStream.addTrack()` and have it played (Firefox bug 1223696).
### MathML
*No change.*
### SVG
* SVG stroke hit-testing is buggy when cairo is the Moz2D backend (Firefox bug 676001).
* Unable to interact with elements who have large transform / translate values (Firefox bug 1217012).
### Audio/Video
* Fixed: Regression (since Firefox 41) whereby audio playback was stuttering due to duration time rounding errors (Firefox bug 1222866.)
HTTP
----
* The `jar:` protocol has been disabled by default when accessed from Web content; you may enable this if necessary by setting the `network.jar.block-remote-files` preference to `false` (Firefox bug 1215235).
Security
--------
* A `Content-Security-Policy` can now be specified using a `<meta>` element (Firefox bug 663570).
* Support of the `child-src` CSP policy directive has been implemented (Firefox bug 1045891).
* EV certificates with a validity greater than 27 months are now considered and handled as DV certificates (Firefox bug 1222903).
Changes for add-on and Mozilla developers
-----------------------------------------
### Interfaces
*No change.*
### XUL
* Tab Groups have been removed.
### JavaScript code modules
*No change.*
### XPCOM
*No change.*
### Search plugins
Starting in Firefox 45, search plugins located in the user's profile's `searchplugins` directory are no longer automatically loaded on startup. Instead, a list of user-installed plugins is maintained and only those plugins are loaded. In effect, this means that the only ways to install new search plugins are for the user to do so in the Firefox UX (via OpenSearch discovery, for instance) or for an add-on to install it. Also, when a new search plugin is installed, more information is recorded about where it came from, for future use by profile debugging and cleaning tools.
### Other
* WebIDL constructors could be called without the `new` operator in chrome context. Now such code will raise a `TypeError` as in Web content since Firefox 30. For example, `var req = XMLHttpRequest();` needs to be `var req = new XMLHttpRequest();`.
Older versions
--------------
* Firefox 44 for developers
* Firefox 43 for developers
* Firefox 42 for developers
* Firefox 41 for developers
* Firefox 40 for developers
* Firefox 39 for developers
* Firefox 38 for developers
* Firefox 37 for developers
* Firefox 36 for developers
* Firefox 35 for developers
* Firefox 34 for developers
* Firefox 33 for developers
* Firefox 32 for developers
* Firefox 31 for developers
* Firefox 30 for developers
* Firefox 29 for developers
* Firefox 28 for developers
* Firefox 27 for developers
* Firefox 26 for developers
* Firefox 25 for developers
* Firefox 24 for developers
* Firefox 23 for developers
* Firefox 22 for developers
* Firefox 21 for developers
* Firefox 20 for developers
* Firefox 19 for developers
* Firefox 18 for developers
* Firefox 17 for developers
* Firefox 16 for developers
* Firefox 15 for developers
* Firefox 14 for developers |
Firefox 3.5 for developers - Mozilla | Firefox 3.5 for developers
==========================
Firefox 3.5 (*released June 30, 2009)* introduces a number of new features, as well as additional and improved support for a wide variety of web standards. This article offers an extensive list, with links to articles covering the major improvements.
New developer features in Firefox 3.5
-------------------------------------
### For website and application developers
#### HTML 5 support
Using audio and video
Firefox 3.5 adds support for the HTML 5 `audio` and `video` elements.
Offline resources in Firefox
Firefox 3.5 now fully supports the HTML 5 offline resource specification.
Drag and drop
The HTML 5 drag and drop API allows support for dragging and dropping items within and between websites. This also provides a simpler API for use by extensions and Mozilla-based applications.
#### Newly-supported CSS features
Downloadable fonts support
The new `@font-face` @rule lets web pages provide downloadable fonts, so that sites can be rendered exactly as the page author expects.
CSS media queries
Firefox 3.5 now supports CSS media queries, which enhance support for media-dependent style sheets.
`::before` and `::after` updated to CSS 2.1
The `::before` and `::after` pseudo-elements have been updated to full CSS 2.1 support, adding support for the `position`, `float`, `list-style-*`, and some `display` properties.
`ch` units for length
The `ch` unit can now be used anywhere that accepts a unit of length. `1ch` is the width of the "0" (zero) character.
`opacity`
The `-moz-opacity` Mozilla extension to CSS has been removed in favor of the standard `opacity` property.
`text-shadow`
The `text-shadow` property, which allows web content to specify shadow effects to apply to text and text decorations, is now supported.
`overflow-wrap`
This newly-supported property lets content specify whether or not lines may be broken within words in order to prevent overflow when an otherwise unbreakable string is too long to fit on one line.
`white-space` property supports the `pre-line` value
The `white-space` property now accepts the `pre-line` value.
`-moz-box-shadow`
`-moz-border-image`
`-moz-column-rule`
`-moz-column-rule-width`
`-moz-column-rule-style`
`-moz-column-rule-color`
Firefox 3.5 adds support for these Mozilla extensions to CSS.
The `-moz-nativehyperlinktext` color value
This new color value represents the user's system's default hyperlink color.
The `-moz-window-shadow` property and the `:-moz-system-metric(mac-graphite-theme)` pseudo-class
These new CSS features were added to facilitate theming.
New values for `-moz-appearance`
The `-moz-win-glass` and `-moz-mac-unified-toolbar` values have been added to `-moz-appearance`.
Using CSS transforms
Firefox 3.5 supports CSS transforms. See `-moz-transform` and `-moz-transform-origin` for details.
`:nth-child``:nth-last-child``:nth-of-type``:nth-last-of-type``:first-of-type``:last-of-type``:only-of-type`
These selectors are all newly-supported in Firefox 3.5.
#### New DOM features
localStorage
Firefox 3.5 adds support for the Web Storage `localStorage` property, which provides a way for web applications to store data locally on the client's computer.
Using web workers
Firefox 3.5 supports web workers to allow easy multi-threading support in web applications.
Using geolocation
Firefox 3.5 supports the Geolocation API, which allows web applications to obtain information about the user's current location if a provider for that information is installed and enabled.
Locating DOM elements using selectors
The selectors API allows querying a document to locate the elements that match a given selection rule.
Mouse gesture events
Firefox 3.5 supports mouse gesture events such as trackpad swipes.
The `NodeIterator` object
The `NodeIterator` object provides support for iterating over the list of the nodes in a DOM subtree.
The `MozAfterPaint` event
This new DOM event is sent after painting updates in windows.
The `MozMousePixelScroll` event
This new DOM event allows detection of pixel-based mouse scroll wheel events instead of line-based scroll events.
#### New JavaScript features
New in JavaScript 1.8.1
An overview of all the changes in JavaScript 1.8.1.
`Object.getPrototypeOf()`
This new method returns the prototype of a specified object.
Using native JSON
Firefox 3.5 has native support for JSON.
New trim methods on the String object
The `String` object now has `trim()`, `trimLeft()`, and `trimRight()` methods.
#### Networking
Cross-site access controls for HTTP
In Firefox 3.5, it's now possible for HTTP requests, including those made by `XMLHttpRequest`, to work across domains if the server supports it.
Progress events for `XMLHttpRequest`
Progress events are now offered to enable extensions to monitor the progress of requests.
Improved Synchronous `XMLHttpRequest` support
DOM Timeout and Input Events are now suppressed during a synchronous `XMLHttpRequest`.
Controlling DNS prefetching
Firefox 3.5 provides DNS prefetching, whereby it performs domain name resolution ahead of time for links included in the current page, in order to save time when links are actually clicked. This article describes how you can tune your website to disable prefetching, or to adjust how prefetching operates.
#### New Canvas features
HTML 5 text API for `canvas` elements
Canvas elements now support the HTML 5 text API.
Shadow effects in a `canvas`
Canvas shadow effects are now supported.
`createImageData()`
The canvas method `createImageData()` is now supported, allowing code to specifically create an `ImageData` object instead of requiring it to be done automatically. This can improve performance of other `ImageData` methods by preventing them from having to create the object.
`moz-opaque` attribute
Added the `moz-opaque` attribute, which lets the canvas know whether or not translucency will be a factor. If the canvas knows there's no translucency, painting performance can be optimized. See also `HTMLCanvasElement.mozOpaque`.
#### New SVG features
Applying SVG effects to HTML content
You can now apply SVG effects to HTML and XHTML content; this article describes how.
#### Miscellaneous new features
ICC color correction in Firefox
Firefox 3.5 now supports ICC color correction for tagged images.
The `defer` attribute is now supported on `script` elements
This attribute indicates to the browser that it *may* choose to continue to parse and render the page without waiting for the script to finish executing.
### Other improvements
* The Text node's `wholeText` property and `Text.replaceWholeText()` method have been implemented.
* The property `element.children` has been added. It returns a *collection* of child elements of the given element.
* The property `HTMLElement.contentEditable` is now supported, to support editable elements.
* The Element Traversal API is now supported by the DOM Element object.
* HTML document nodes may now be cloned using `cloneNode()`.
* The non-standard `getBoxObjectFor()` DOM method has been removed. You should be using `getBoundingClientRect()` instead.
* Dispatched DOM events can now be re-dispatched. This makes Firefox 3.5 pass Acid 3 test 30.
* Improvements have been made to DOM 2 Range handling.
* In non-chrome scope, caught objects in exceptions are now the actual thrown object instead of an `XPConnect` wrapper containing the thrown object.
* SVG ID references are now live.
* SVG filters now work for `foreignObject`.
* The `GetSVGDocument()` method has been added to `object` and `iframe` elements for compatibility.
* Implicit setting of properties in object and array initializers no longer execute setters in JavaScript.
* The `gDownloadLastDir.path` variable has been renamed to `gDownloadLastDir.file` since it refers to an `nsIFile`, not a path.
* The `gDownloadLastDirPath` variable has been renamed to `gDownloadLastDirFile` since it refers to an `nsIFile`, not a path.
* Starting in Firefox 3.5, you can no longer use `data:` bindings in chrome packages that get `XPCNativeWrapper` automation.
### For XUL and add-on developers
If you're an extension developer, you should start by reading Updating extensions for Firefox 3.5, which offers a helpful overview of what changes may affect your extension.
#### New components and functionality
Supporting private browsing mode
Firefox 3.5 offers Private Browsing mode, which doesn't record the user's activities. Extensions may support private browsing following the guidelines offered by this article.
Security changes in Firefox 3.5
This article covers security-related changes in Firefox 3.5.
Theme changes in Firefox 3.5
This article covers theme-related changes in Firefox 3.5.
Monitoring Wi-Fi access points
Code with UniversalXPConnect privileges can now monitor the list of available access points, getting information on their SSIDs, MAC addresses, and signal strength. This can be used in tandem with Geolocation to offer Wi-Fi-based location service.
#### Notable changes and improvements
* The XUL `textbox` widget now offers a `search` type, for use as search fields.
* In order to support dragging and dropping tabs between windows, the `browser` widget now has a `swapDocShells()` method.
* Added the `level` attribute to the `panel` element; this specifies whether panels appear on top of other applications, or just on top of the window the panel is contained within.
* XUL elements now support the `clientHeight`, `clientWidth`, `scrollHeight`, and `scrollWidth` properties.
* `keyset` now include a `disabled` attribute.
* In addition, `keyset`s can now be removed using the node's `removeChild()` method.
* `mozIStorageStatement` had the `initialize()` method removed; consumers should use the `createStatement()` method instead to get a new statement object.
* The Storage API now offers support for asynchronous requests.
* The `nsICookie2` interface now exposes the time at which cookies were created in its new `creationTime` attribute.
* Added a flag to `nsIProtocolHandler` (`URI_IS_LOCAL_RESOURCE`) that is checked during chrome registration to make sure a protocol is allowed to be registered.
* Firefox now looks for plugins in `/usr/lib/mozilla/plugins` on Linux, as well as the previously supported locations.
* The plugin API has been updated to include support for private browsing mode; you may now use `NPN_GetValue()` to query the state of private browsing mode using the variable `NPNVprivateModeBool`.
New features for end users
--------------------------
### User experience
Location aware browsing
If you choose, you may allow Firefox 3.5 to share information about your current location with websites. Firefox 3.5 can use information about the network you're connected to in order to share your location. Of course, it asks for your permission before doing so, to ensure your privacy.
Open audio and video support
Firefox 3.5 supports embedded video and audio using the open Ogg format, as well as WAV for audio. No plugins, no confusing error messages about needing to install something or other that turns out not to be available on your platform anyway.
Local data storage
Web applications can now use Web Storage's local storage capabilities to store data on your computer. This is great for anything from site preferences to more complex data.
### Security and privacy
Private Browsing
Need to use someone else's computer? Switch on Private Browsing mode and nothing will be recorded about your session, including cookies, history, and any other potentially private information.
Better privacy controls
The Privacy preference pane has been completely redesigned to offer users more control over their private information. Users can choose to retain or discard anything including history information, cookies, downloads, and form field information. In addition, users can specify whether or not to include history and/or bookmarks in the location bar's automated suggestions, so you can keep private web addresses from popping up unexpectedly while typing in the location bar.
### Performance
Faster JavaScript performance
JavaScript, the "J" in "AJAX," is sped up dramatically in Firefox 3.5 with the new TraceMonkey JavaScript engine. Web applications are much faster than in Firefox 3.
Faster page rendering
Web content draws faster in Firefox 3.5, thanks to technologies such as "speculative parsing." Your users don't need to know what it means, other than "it makes things draw faster."
See also
--------
* Firefox 3 for developers
* Firefox 2 for developers
* Firefox 1.5 for developers |
Firefox 113 for developers - Mozilla | Firefox 113 for developers
==========================
This article provides information about the changes in Firefox 113 that affect developers. Firefox 113 was released on May 09, 2023.
Changes for web developers
--------------------------
### HTML
No notable changes.
### CSS
* The `color()`, `lab()`, `lch()`, `oklab()`, `oklch()`, and `color-mix()` functional notations are now supported, along with the `forced-color-adjust` property.
For more information on the functional notations, see the CSS color value documentation.
(Firefox bug 1352753, Firefox bug 1813497, Firefox bug 1818819, Firefox bug 1824526).
* The `:nth-child of <selector>` syntax allows you to target a group of children based upon the `An+B` rule that also matches a defined selector.
See (Firefox bug 1808229) for more details.
* The `scripting` media feature is now supported. See (Firefox bug 1166581) for more details.
* The `content` property now supports all image type including, `<gradient>`, `image-set()` and `url()`. See (Firefox bug 1684958) for more details. There is currently an issue with the `::before` and `::after` pseudo selectors that means that they don't paint `<gradient>`s. See (Firefox bug 1832901) for more details.
### JavaScript
No notable changes.
### APIs
* `CanvasRenderingContext2D.reset()` and `OffscreenCanvasRenderingContext2D.reset()` are now supported, and can be used to return the associated rendering context to its default state.
(Firefox bug 1709347).
* The Compression Streams API is now supported.
The interfaces provided by this API are used to compress and decompress data using the `gzip` and `deflate` formats (Firefox bug 1823619).
* The deprecated and non-standard `mozImageSmoothingEnabled` property is now disabled.
See the `imageSmoothingEnabled` property for smoothing in scaled images (Firefox bug 1822955).
#### Media, WebRTC, and Web Audio
* The AV1 video codec is now enabled on Android. Hardware accelerated decoding is used if supported by the device (Firefox bug 1672276).
* The following WebRTC methods, properties, and dictionaries are now supported: `RTCRtpSender.getCapabilities()`, `RTCRtpReceiver.getCapabilities()`, `RTCRtpSender.setStreams()`, `RTCSctpTransport` & `RTCPeerConnection.sctp`, `RTCMediaSourceStats`, `RTCPeerConnection.connectionState`, and `RTCPeerConnectionStats`.
The corresponding bug reports are, respectively: Firefox bug 1531460, Firefox bug 1531461, Firefox bug 1510802, Firefox bug 1278299, Firefox bug 1804678, Firefox bug 1265827, and Firefox bug 1531087.
#### Removals
* The deprecated and non-standard `CanvasRenderingContext2D.mozTextStyle` attribute was permanently removed. This was previously hidden behind a preference. (Firefox bug 1294362).
* The deprecated and non-standard attributes `mozRTCPeerConnection`, `mozRTCIceCandidate`, and `mozRTCSessionDescription` were permanently removed (Firefox bug 1531812).
### WebDriver conformance (WebDriver BiDi, Marionette)
#### WebDriver BiDi
* Added support for serializing `Node` objects within a Shadow DOM and the `shadowRoot` property on `Node` objects (Firefox bug 1802137).
* Added support for cached responses for the `network.responseStarted` and `network.responseCompleted` events (Firefox bug 1806802 and Firefox bug 1806794).
* Fixed an issue where the `browsingContext.domContentLoaded` and `browsingContext.load` events were missing for navigations using `document.open()` and `document.close()` (Firefox bug 1822772).
* Fixed an issue where the `script.callFunction` command was throwing an `invalid argument` error if an unknown object was passed as an argument, instead of the expected `no such handle` error (Firefox bug 1821039).
#### Marionette
* The `moz:useNonSpecCompliantPointerOrigin` capability is now deprecated and will be fully removed in Firefox 116 (Firefox bug 1824911).
* Implemented the `WebDriver:FindElementFromShadowRoot` and `WebDriver:FindElementsFromShadowRoot` commands (Firefox bug 1700095).
* Implemented the `WebDriver:GetComputedLabel` and `WebDriver:GetComputedRole` commands (Firefox bug 1585622).
* Added support for the `background` parameter of the `WebDriver:Print` command (Firefox bug 1783086).
* Added support for the `orientation` parameter of the `WebDriver:Print` command (Firefox bug 1791819).
* Fixed an issue with `DOMTokenList` instances, which are now returned as collections instead of arbitrary objects (Firefox bug 1823464).
Changes for add-on developers
-----------------------------
* When an extension registers multiple listeners for the same event, all the event listeners are called when the event page wakes up, instead of only the first one (Firefox bug 1798655).
* Support is now provided for the `declarativeNetRequest` API (Firefox bug 1782685).
* The `gecko_android` subkey has been added to the `browser_specific_settings` key. This subkey enables an extension to specify the range of Firefox for Android versions it is compatible with (Firefox bug 1824237).
Older versions
--------------
* Firefox 112 for developers
* Firefox 111 for developers
* Firefox 110 for developers
* Firefox 109 for developers
* Firefox 108 for developers
* Firefox 107 for developers
* Firefox 106 for developers
* Firefox 105 for developers
* Firefox 104 for developers
* Firefox 103 for developers
* Firefox 102 for developers
* Firefox 101 for developers
* Firefox 100 for developers
* Firefox 99 for developers
* Firefox 98 for developers
* Firefox 97 for developers
* Firefox 96 for developers
* Firefox 95 for developers
* Firefox 94 for developers
* Firefox 93 for developers
* Firefox 92 for developers
* Firefox 91 for developers
* Firefox 90 for developers
* Firefox 89 for developers
* Firefox 88 for developers
* Firefox 87 for developers
* Firefox 86 for developers
* Firefox 85 for developers
* Firefox 84 for developers
* Firefox 83 for developers
* Firefox 82 for developers |
Firefox 59 for developers - Mozilla | Firefox 59 for developers
=========================
This article provides information about the changes in Firefox 59 that will affect developers. Firefox 59 was released on March 13, 2018.
Changes for web developers
--------------------------
### Developer tools
* The Network Monitor Response tab now shows a preview of the rendered HTML — if the response is HTML (Firefox bug 1353319).
* Cookie information shown in the Storage Inspector (see Cookies) now includes a *sameSite* column showing what the same-site status of each cookie is (Firefox bug 1298370).
* The Rulers tool now includes a readout showing the current dimensions of the viewport (Firefox bug 1402633).
* In Responsive Design Mode, you can now set the screen dimensions using the cursor keys (Firefox bug 1421663). See the Setting screen size section for more details.
* The *Raw headers* display in the Network Monitor *Headers* tab now includes the response's status code (Firefox bug 1419401).
### HTML
* The `<textarea>` element's `autocomplete` attribute has been implemented. This lets you enable or disable form auto-fill for the element.
### CSS
* The `overscroll-behavior` property and its associated longhand properties — `overscroll-behavior-x` and `overscroll-behavior-y` — have been implemented (Firefox bug 951793), and it has been enabled by default on all releases (Firefox bug 1428879).
* The behavior of "unusual elements" (elements that aren't rendered purely by CSS box concepts such as replaced elements) when given a `display` value of `contents` has been updated as per spec (Firefox bug 1427292). See Appendix B: Effects of display: contents on Unusual Elements for exactly what the specified behaviors are.
* `position` `sticky` is now supported on appropriate HTML table parts (e.g. `<th>` elements) (Firefox bug 975644).
* `calc()` is now supported in `<color>` values — `rgb()`, `rgba()`, `hsl()`, and `hsla()` (Firefox bug 984021).
* `calc()` in media query values is now supported Firefox bug 1396057.
* The `@document` at-rule has been limited to use only in user and UA sheets (Firefox bug 1035091).
* Implement the `font-optical-sizing` property (Firefox bug 1435692).
### SVG
*No changes.*
### JavaScript
*No changes.*
### APIs
#### New APIs
* `PointerEvents` have been enabled in Firefox Desktop (Firefox bug 1411467).
#### DOM
* The `EventTarget()` constructor has been implemented (Firefox bug 1379688).
* The `Response()` constructor can now accept a `null` value for its `body` parameter, as per spec (Firefox bug 1303025).
#### DOM events
* The `Event.composedPath()` method has been implemented (Firefox bug 1412775).
#### Service workers
* The service worker Clients API can now find and communicate with windows in a separate browser process (Firefox bug 1293277) .
* Nested about:blank and about:srcdoc iframes will now inherit their parent's controlling service worker. Fixed in (Firefox bug 1293277) and (Firefox bug 1426979).
* When a service worker provides a `Response` to `FetchEvent.respondWith()`, the `Response.url` value will now be propagated to the intercepted network request as the final resolved URL. In the past the `FetchEvent.request.url` was used for this instead. This means, for example, if a service worker intercepts a stylesheet or worker script, then the provided `Response.url` will be used to resolve any relative `@import` or `importScripts()` subresource loads (Firefox bug 1222008).
* `FetchEvent.respondWith()` will now trigger a network error if the `FetchEvent.request.mode` is `"same-origin"` and the provided `Response.type` is `"cors"`. (Firefox bug 1222008)
#### Media and WebRTC
* The `MediaStreamTrack` property `MediaStreamTrack.muted`, along with the events `mute` and `unmute` and the corresponding event handlers, `onmute` and `onunmute`, have been implemented. A track's `muted` state indicates that the track is not currently able to provide media data.
**Note:** The `muted` state of a track isn't useful for what's typically thought of as muting and unmuting a track. Instead, use the `enabled` property; setting `enabled` to `false` causes the track to output only empty frames.
* Firefox 59 on Android now supports Apple's HTTPS Live Streaming (HLS) protocol for both audio and video. This non-standard protocol is being supported on mobile to improve compatibility with sites that require it for mobile streaming. There is not currently any plan to implement it on Firefox Desktop.
* The `RTCRtpReceiver` methods `getContributingSources()` and `getSynchronizationSources()` have been implemented to provide information about the sources of each RTP stream. However, a specification change occurred before release and we have disabled these by default behind the preference `media.peerconnection.rtpsourcesapi.enable` (Firefox bug 1363667, Firefox bug 1430213, and Firefox bug 1433236.
* The `RTCRtpTransceiver` interface has now been implemented, since the Firefox implementation of WebRTC now supports transceivers, with `RTCPeerConnection` and other interfaces updated to use them per the latest specification.
* The `RTCPeerConnection.addTransceiver()` method has been added. In addition, the behavior of `addTrack()` has been updated to create a transceiver as required.
* Support for WebVTT regions was implemented in Firefox 58 but disabled by default. They're now available by default (Firefox bug 1415805).
* Firefox now supports WebVTT `REGION` definition blocks whose settings list has one setting per line instead of all of the settings being on the same line of the WebVTT file (Firefox bug 1415821.
#### Canvas and WebGL
*No changes.*
### CSSOM
The `CSSNamespaceRule` interface and its `namespaceURL` and `prefix` properties have been implemented (Firefox bug 1326514).
### HTTP
*No changes.*
### Security
* Top-level navigation to `data:` URLs has been blocked Firefox bug 1401895. See Blocking Top-Level Navigations to data URLs for Firefox 59 for more details.
* The `SAMEORIGIN` directive of the `X-Frame-Options` header has been changed so that it checks not only the top-level IFrame is in the same origin, but all its ancestors as well (Firefox bug 725490).
* Image resources loaded from different origins to the current document are no longer able to trigger HTTP authentication dialogs (Firefox bug 1423146).
* HTTP authentication now uses `utf-8` encoding for usernames and passwords (rather than `ISO-8859-1`) for parity with other browsers, and to avoid potential problems as described in Firefox bug 1419658.
* Everyday the HSTS preload list is updated from Google. Normally this doesn't warrant a note, but in this release new TLDs were included, notably `.app` and `.dev`. While they are new TLDs developers might have used them for local development and be surprised by this change. Note that reserved TLDs should be used for local development instead.
### Plugins
*No changes.*
### Other
*No changes.*
Removals from the web platform
------------------------------
### HTML
The non-standard `version` parameter of the `<script>` element's `type` attribute (e.g. `type="application/javascript;version=1.8"`) has been removed (Firefox bug 1428745).
### CSS
* The proprietary `mozmm` `<length>` unit has been removed (Firefox bug 1416564).
* The proprietary `-moz-border-top-colors`, `-moz-border-right-colors`, `-moz-border-bottom-colors`, and `-moz-border-left-colors` properties have been limited to usage in chrome code only (Firefox bug 1417200).
### JavaScript
* Non-standard conditional catch clauses have been removed (Firefox bug 1228841).
### APIs
* The non-standard method `Event.getPreventDefault()` has been removed. You should instead use the `Event.defaultPrevented` property to determine whether or not `preventDefault()` was called on the `Event`.
* The proprietary `Navigator.mozNotification` property and `DesktopNotification` interface have been removed, in favor of the standard Notifications API (Firefox bug 952453).
* The proprietary `window.external.addSearchEngine()` method has been removed (Firefox bug 862147). Also see `Window.sidebar` for more details.
* The non-standard Firefox-only `HTMLMediaElement` property `mozAutoplayEnabled` has been removed.
### SVG
Support for SMIL's `accessKey` feature has been removed (Firefox bug 1423098).
### Other
Support for the non-standard `pcast:` and `feed:` protocols has been removed from Firefox (Firefox bug 1420622).
Changes for add-on and Mozilla developers
-----------------------------------------
### WebExtensions
* Theme updates:
+ new properties: `colors.background_tab_text`, `colors.toolbar_field_border`
+ all color properties now support both Chrome-style arrays and CSS color values.
* New browser settings:
+ `contextMenuShowEvent`
+ `openBookmarksInNewTabs`
+ `openSearchResultsInNewTabs`
+ `proxyConfig`
* New `tabs` APIs:
+ `tabs.captureTab()`
+ `tabs.hide()`
+ `tabs.show()`
* The `contextMenus` API now supports a "bookmark" context.
* New `contentScripts` API enables runtime registration of content scripts.
* New `pageAction`, `browserAction`, `SidebarAction` APIs:
+ `browserAction/pageAction/sidebarAction.set*` functions now accept `null` to undo changes.
+ `browserAction.isEnabled()`, `pageAction.isShown()`, `sidebarAction.isOpen()` functions.
* New option in `page_action` to show page actions by default.
* New values for `protocol_handlers`:
+ "ssb" for Secure Scuttlebutt communications
+ "dat" for DATproject
+ "ipfs", "ipns", "dweb" for IPFS
* New `privacy.websites` setting "cookieConfig".
* Support in `cookies` API for first-party isolation.
* New option `upgradeToSecure` in `webRequest`.
Older versions
--------------
* Firefox 58 for developers
* Firefox 57 for developers
* Firefox 56 for developers
* Firefox 55 for developers
* Firefox 54 for developers
* Firefox 53 for developers
* Firefox 52 for developers
* Firefox 51 for developers
* Firefox 50 for developers
* Firefox 49 for developers
* Firefox 48 for developers
* Firefox 47 for developers
* Firefox 46 for developers
* Firefox 45 for developers
* Firefox 44 for developers
* Firefox 43 for developers
* Firefox 42 for developers
* Firefox 41 for developers
* Firefox 40 for developers
* Firefox 39 for developers
* Firefox 38 for developers
* Firefox 37 for developers
* Firefox 36 for developers
* Firefox 35 for developers
* Firefox 34 for developers
* Firefox 33 for developers
* Firefox 32 for developers
* Firefox 31 for developers
* Firefox 30 for developers
* Firefox 29 for developers
* Firefox 28 for developers |
Firefox 12 for developers - Mozilla | Firefox 12 for developers
=========================
Firefox 12 was shipped on April 24, 2012. This page summarizes the changes in Firefox 12 that affect developers. This article provides information about the new features and key bugs fixed in this release, as well as links to more detailed documentation for both web developers and add-on developers.
Changes for Web developers
--------------------------
### HTML
* The `title` attribute now supports newline characters to allow multi-line tooltips.
* If JavaScript is disabled, the `<canvas>` element was being rendered instead of showing the fallback content as per the specification. Now the fallback content is rendered instead.
* The `crossorigin` attribute is now supported on `<video>`.
### CSS
* Support for the `text-align-last` property has been added (prefixed).
### JavaScript
* Support for sharp variables (a Netscape non-standard extension) has been dropped.
* `ArrayBuffer.prototype.slice()` has been implemented.
### DOM
* `DOMParser` now supports parsing of HTML document fragments.
* `XMLHttpRequest` now supports timeouts using the `timeout` property and "timeout" event, as well as the `ontimeout` event handler on the `XMLHttpRequestEventTarget` interface.
* `XMLHttpRequest` can now load from `data:` URLs.
* When downloading large amounts of data, `XMLHttpRequest` progress event handlers are now called periodically with the `responseType` set to "moz-blob" and the response being a `Blob` containing all of the data received so far. This lets progress handlers begin processing data without having to wait for it all to arrive.
* Gecko now supports multi-touch (instead of just single touches at a time) on Android.
* While editing text using an IME, the `input` event is now sent whenever the contents of the element being edited have been changed; this happens after the `compositionupdate` event has been sent to indicate that the IME's text has been changed. You can use the `input` event handler, therefore, to monitor changes to the actual content of the element.
* `DOMError` as defined in the DOM 4 specification has been implemented.
* The `Document.createNodeIterator()` method has been updated to match the DOM4 specification. This makes the `whatToShow` and `filter` parameters optional and removes the non-standard fourth parameter, `entityReferenceExpansion`.
* The `Blob` interface's `slice()` method was affected by a bug that prevented it from properly accepting `start` and `end` values outside the range of a signed 64-bit integer; this has been fixed.
* The `element.getBoundingClientRect()` method now considers effect of CSS transforms when computing the element's bounding rectangle.
* The `crossOrigin` property is now supported by `HTMLMediaElement`.
#### New WebAPIs
* Network Information API: Experimental support for `window.navigator.connection` has been added (prefixed).
* WebTelephony API: `window.navigator.mozTelephony` has been implemented and provides support for dialing, answering, and managing phone calls on a device.
* WebSMS API: `window.navigator.mozSms` is now available for mobile devices to send SMS text messages.
* Screen brightness API: `window.screen.mozEnabled` and `window.screen.mozBrightness` have been added to control the device's screen.
### SVG
* Firefox now implements the `SVGTests` DOM API, see Firefox bug 607854
* The `SVGStringList` DOM interface support the non-standard `length` property see Firefox bug 711958
### MathML
* To control the directionality of MathML formulas, the `dir` attribute is now supported on the `<math>`, `<mrow>`, and `<mstyle>` elements as well as on MathML Token Elements. This is particularly important for some Arabic mathematical notations.
* The alignment attribute `align` defined in MathML3 has been implemented for `<munder>`, `<mover>`, and `<munderover>`.
### Networking
* Previously, Gecko reported the close code `CLOSE_NORMAL` when a WebSocket channel was closed due to an unexpected error, or if it was closed due to an error condition that the specification doesn't cover. Now `CLOSE_GOING_AWAY` is reported instead.
### Developer tools
* The Web Console now caches error messages and log entries added using `console.log()` if the console isn't currently open, and displays them when the console is opened.
* You can now reset the zoom level, panning, and rotation in the 3D view by pressing the "r" key.
* You can now hide nodes in the 3D view by pressing the "x" key after selecting them.
* The source editor has a several new editing features and keyboard shortcuts; see Using the Source Editor for details
Mozilla has been working on integrating its own Web developer tools that complement the popular Firebug add-on. You can get more information about these tools as well as see a list of resources external to Firefox that will help you with your Web development. The entire list is located at Web developer tools.
### Miscellaneous changes
* The GEOSTD8 character set, which was never fully supported, is no longer supported at all.
Changes for Mozilla and add-on developers
-----------------------------------------
### JavaScript code modules
#### source-editor.jsm
* The `resetUndo()` method was added; this lets you clear the undo stack.
* The source editor now offers methods for providing search capability: `find()`, `findNext()`, and `findPrevious()`.
### XUL
* The definition of the values for the `chromemargin` attribute has changed slightly, to make it easier to make cross-platform XUL code look good on platforms with different default window border widths.
### XPCOM
* `nsISupports` proxies are no longer supported. You should be using runnables instead.
* Firefox 11 changed the behavior of `Components.utils.getWeakReference()` to throw an exception when the object reference is null; the previous behavior of silently failing has been restored.
### XPConnect
* The `PRUint64` data type was incorrectly essentially identical to `PRint64` when used with XPConnect. This has been fixed.
### Interface changes
* The `nsIScreen_MOZILLA_2_0_BRANCH` interface has been merged into `nsIScreen`. The APIs defined in that interface (for controlling minimum screen brightness) had not previously been documented, but now they are.
* The `nsIScriptError2` interface has been merged into `nsIScriptError`.
* `nsIDownloadManager.addDownload()` is now handled asynchronously rather than synchronously.
* The `imgIContainerObserver.frameChanged()` method now receives as its first parameter an `imgIRequest` object identifying the corresponding request.
* The `nsIDOMWindowUtils.sendTouchEvent()` method has been added to allow synthesizing touch events.
* You can now scroll the specified content to the vertical center of the view by specifying `SCROLL_CENTER_VERTICALLY` as the scroll constant when calling `nsISelectionController.scrollSelectionIntoView()`.
* The new `nsIMemoryMultiReporter.explicitNonHeap` attribute has been added; this is a more efficient way to obtain the sum of all of the multi-reporter's measurements that have a path that starts with "explicit" **and** are of the kind `KIND_NONHEAP`.
* The `nsIDOMWindowUtils.paintingSuppressed` attribute has been added; this boolean value indicates whether or not painting is currently suppressed on the window. This is used on mobile to prevent bouncy rendering that occurs when attempts to draw the page begin before enough content is available to do so smoothly.
* The `nsIDocCharset` and `nsIDocumentCharsetInfo` interfaces have been merged into `nsIDocShell`. As part of this work, the old `forcedDetector` attribute has been removed; it never did anything.
### SpiderMonkey
* `JSThread` has been eliminated.
* `JSThreadData` has been merged into `JSRuntime`.
### Building
* When building on Windows, you must have the Windows 7 SDK installed.
### Other changes
* The editor component (known as Midas) now only accepts events from privileged code.
See also
--------
* Firefox 11 for developers
* Firefox 10 for developers
* Firefox 9 for developers
* Firefox 8 for developers
* Firefox 7 for developers
* Firefox 6 for developers
* Firefox 5 for developers
* Firefox 4 for developers
* Firefox 3.6 for developers
* Firefox 3.5 for developers
* Firefox 3 for developers
* Firefox 2 for developers
* Firefox 1.5 for developers |
Firefox 2 for developers - Mozilla | Firefox 2 for developers
========================
New developer features in Firefox 2
-----------------------------------
Firefox 2 introduces a vast array of new features and capabilities. This article provides links to articles covering the new features.
### For website and application developers
Microsummaries
Microsummaries are regularly-updated succinct compilations of the most important information on web pages. Site and third-party developers can both provide them, and users can choose to display microsummaries instead of static titles when they bookmark pages with microsummaries.
Creating a Microsummary
A tutorial on creating a microsummary generator.
Microsummary XML grammar reference
A reference guide to the XML grammar used for creating microsummary generators.
Creating OpenSearch plugins for Firefox
Firefox 2 supports the OpenSearch search engine format.
Creating MozSearch plugins
Firefox 2 supports MozSearch, a search plugin format based on OpenSearch, but intended only for internal use.
Supporting search suggestions in search plugins
How to make your MozSearch plugin support search suggestions, which appear in a drop-down list while typing in the search bar.
New in JavaScript 1.7
Firefox 2 supports JavaScript 1.7, which includes new features including `let`, destructuring assignment, generators and iterators, and array comprehensions.
WHATWG Client-side session and persistent storage (aka DOM Storage)
Client-side session and persistent storage allows web applications to store structured data on the client side.
SVG in Firefox
Firefox 2 improves Scalable Vector Graphics (SVG) support, implementing the `<textPath>` element and adding support for some attributes not previously supported.
Controlling spell checking in HTML forms
Firefox 2 includes support for inline spell checking in text areas and text fields. This article describes how to write your HTML to enable and disable spell checking on individual form elements.
Security in Firefox 2
Firefox 2 has changes to which security protocols are enabled by default.
### For XUL and extension developers
Updating extensions for Firefox 2
Covers how to get your existing extensions to work with Firefox 2.
Session store API
Contributing items to be saved and restored across sessions in Firefox.
Feed content access API
API that lets developers access and parse RSS and Atom feeds.
SAX support
Event-based XML parser API.
Adding search engines from web pages
JavaScript code can instruct Firefox to install a new search engine plugin, which can be written using either OpenSearch or Sherlock format.
Using spell checking in XUL
How to check the spelling of words or get a list of suggested spellings from code.
Adding phishing protection data providers
It's possible to enhance Firefox's phishing protection by adding additional data providers for the safe browsing system.
Adding feed readers to Firefox
You can add new feed readers to Firefox, whether web-based or application-based.
Storage
Firefox 2 introduces mozStorage, an sqlite based database architecture.
Theme changes in Firefox 2
Discusses the changes needed to update existing themes to work in Firefox 2.
Textbox Improvements (Firefox 2.0.0.1 and higher only)
The `<textbox>` now has a `reset()` method to reset the value of the textbox to the default value. The `defaultValue` property may be used to retrieve and modify the default value of the textbox (Firefox bug 312867). Supports an `editor` property to get the internal `nsIEditor` for the text field (Webkit bug 312867).
New features for end users
--------------------------
Firefox 2 provides an enhanced version of the same clean user interface offered by previous versions, with improved security features to make your online experience safer and more convenient than ever.
### User experience
* **Inline spell checking for text areas** lets you compose with confidence in web forms.
* **Microsummaries** provide a way to create bookmarks that display information pulled from the site they refer to, updated automatically. Great for stock tickers, auction monitoring, and so forth.
* **Extension Manager user interface** has been enhanced.
* **Search engine manager** lets you rearrange and remove search engines shown in the search bar.
* **Tabbed browsing enhancements** include adding close buttons to each tab, adjustments to how Firefox decides which tab to bring you to when you close the current tab, and simplified preferences for tabs.
* **Autodetection of search engines** allows search engines that offer plugins for the Firefox search bar to offer to install their plugins for you.
* **Search suggestions** allow search engines to offer suggested search terms based on what you've typed so far in the search bar.
### Security and privacy
* **Phishing Protection** to warn users when the website you're looking at appears to be a forgery.
See also
--------
* Firefox 2 for developers
* Firefox 1.5 for developers |
Firefox 23 for developers - Mozilla | Firefox 23 for developers
=========================
Changes for Web developers
--------------------------
### Security
* Mixed content blocking. Firefox will no longer load non-secure (http) resources on secure (https) pages (Firefox bug 834836).
* The standard syntax of CSP 1.0 policies are now implemented and enforced by default.
### Developer Tools
* A Network Panel has been added to the developer tools. This is more detailed view than the "Net" view option in the Web Console.
* Web Console has been renamed "Console", and includes the option to filter security errors/warnings.
* The new Toolbox Options lets you disable features, change light/dark theme, or enable Chrome/Remote debugging.
### HTML
* The `<blink>` element support is now completely dropped. The `<blink>` tag now implements the `HTMLUnknownElement` interface (Firefox bug 857820).
* The `range` type of the `<input>` element (`<input type="range">`) has been switched on by default (Firefox bug 841950).
### JavaScript
* The `Object.defineProperty` method can now be used to redefine the `length` property of an `Array` object.
* The option to disable JavaScript, including the options to allow moving windows/replace context menu, have been removed. You may still disable JavaScript by double clicking the "javascript.enabled" option in about:config.
### DOM
* D3E `KeyboardEvent.key` is now supported, but only for non-printable keys (Firefox bug 842927).
* The `title` attribute of `DOMImplementation.createHTMLDocument` is now optional as per updated DOM specification.
* The ability to add a sidebar panel (`window.sidebar.addPanel`) has been dropped (Firefox bug 691647).
* The unprefixed `Window.requestAnimationFrame` and `Window.cancelAnimationFrame` methods has been added (Firefox bug 704063). The unprefixed `Window.requestAnimationFrame` receives a `DOMHighResTimeStamp` as argument; the prefixed version receives a timestamp in milliseconds (Firefox bug 753453).
* The text argument for `window.alert` and `window.confirm` is now optional (Firefox bug 861605).
* The `HTMLMediaElement.initialTime` property, removed from the spec, is no longer supported (Firefox bug 742537).
* The `AnimationEvent()` constructor has been added (Firefox bug 848293).
* The `AnimationEvent.pseudoElement` property has been implemented (Firefox bug 848293).
* The `TransitionEvent()` constructor has been added (Firefox bug 848291).
* The `TransitionEvent.pseudoElement` property has been implemented (Firefox bug 848291).
* The non-standard `TransitionEvent.initTransitionEvent()` and `AnimationEvent.initAnimationEvent()` have been removed (Firefox bug 868751).
### WebRTC
* Instead of including usernames in the `RTCIceServer.url` property (such as stun:[email protected]), you now need to use the new `RTCIceServer.username` property.
### CSS
* The blink effect for `text-decoration: blink;` has no more effect, but is still a valid value (Firefox bug 857820).
* In-flow `::after` and `::before` pseudo-elements are now flex items (Firefox bug 867454).
* The way to compute viewport units has been changed. In conjunction with `overflow:auto`, space taken by eventual scrollbars is not subtracted from the viewport, whereas in the case of `overflow:scroll`, it is. (Firefox bug 811403)
### MathML
* Negative widths for the `<mspace>` element has been implemented (Firefox bug 717546).
* The `<semantics>` element now determines the visible child as described in the MathML3 specification.
Changes for addon and Mozilla developers
----------------------------------------
### Firefox developer tools
Addons that overlay chrome://browser/content/debugger.xul must now overlay chrome://browser/content/devtools/debugger.xul. You may add references to both these files in chrome.manifest for compatibility.
See also
--------
* Firefox 23 Aurora Notes
### Older versions
* Firefox 22 for developers
* Firefox 21 for developers
* Firefox 20 for developers
* Firefox 19 for developers
* Firefox 18 for developers
* Firefox 17 for developers
* Firefox 16 for developers
* Firefox 15 for developers
* Firefox 14 for developers
* Firefox 13 for developers
* Firefox 12 for developers
* Firefox 11 for developers
* Firefox 10 for developers
* Firefox 9 for developers
* Firefox 8 for developers
* Firefox 7 for developers
* Firefox 6 for developers
* Firefox 5 for developers
* Firefox 4 for developers
* Firefox 3.6 for developers
* Firefox 3.5 for developers
* Firefox 3 for developers
* Firefox 2 for developers
* Firefox 1.5 for developers |
Firefox 68 for developers - Mozilla | Firefox 68 for developers
=========================
This article provides information about the changes in Firefox 68 that will affect developers. Firefox 68 was released on July 9, 2019.
Changes for web developers
--------------------------
### Developer tools
#### Browser/web console
* The Web console now shows more information about CSS warnings, including a node list of the DOM elements that used the rule (Firefox bug 1093953).
* You can now filter content in the Web console using regular expressions (Firefox bug 1441079).
* The Browser console now allows you to show or hide messages from the content process by setting or clearing the checkbox labeled *Show Content Messages* (Firefox bug 1260877).
#### JavaScript debugger
* You can now Search in all files in the current project from the debugger by pressing `Shift` + `Ctrl` + `F` (Windows or Linux) or `Shift` + `Cmd` + `F` (macOS) (Firefox bug 1320325).
#### Network monitor
* The Network monitor request list now allows you to block a specific URL (Firefox bug 1151368).
* You can now resend a network request without editing the method, URL, parameters, and headers, using the Resend command on the context menu (Firefox bug 1422014).
* The context menu of the Network monitor Headers tab now allows you to copy all or some of the header information to the clipboard in JSON format (Firefox bug 1442249).
#### Page inspector
* A button has been added to the rules panel of the Page inspector that allows you to toggle the display of any print media queries (Firefox bug 1534984).
* The fonts panel now includes a slider to modify `letter-spacing` (Firefox bug 1536237).
* A warning icon appears next to unsupported CSS properties or rules that have invalid values, to help you understand why certain styles are not being applied (Firefox bug 1306054).
#### Storage inspector
* You can now delete local and session storage entries by selecting the item in the storage inspector and pressing the backspace key (Firefox bug 1522893).
#### Other
* The Accessibility Inspector now includes a new *Check for issues* feature, which will include a number of audit tools to highlight accessibility problems on your web pages. The first available check is *contrast*, for highlighting color contrast problems.
* The preference that controls the visibility of internal extensions (system add-ons and hidden extensions) on the about:debugging page has been changed from `devtools.aboutdebugging.showSystemAddons` to `devtools.aboutdebugging.showHiddenAddons` (Firefox bug 1544372).
* Responsive design mode has been redesigned — the *Device Settings* dialog (device selection menu > *Edit List…*) is now more intuitive and simpler to use (Firefox bug 1487857).
#### Removals
* The "Enable add-on debugging" checkbox has been removed from the about:debugging page (Firefox bug 1544813).
### HTML
* The `<track>` element — represented by `HTMLTrackElement` — now receives a `cuechange` event in addition to the `TextTrack` itself, if the text track is a contained by a media element (Firefox bug 1548731).
* `<link>` elements support the `disabled` attribute again, albeit with different behavior. When `disabled` is set on a `<link>` element along with `rel="stylesheet"`, the referenced stylesheet is not loaded during page load, and will be loaded on demand when the `disabled` attribute is changed to `false` or removed (Firefox bug 1281135).
#### Removals
* `<meta http-equiv="set-cookie">` is no longer supported (Firefox bug 1457503).
### CSS
* CSS Scroll Snapping has been updated to the latest version of the specification (Firefox bug 1312163) and (Firefox bug 1544136), this includes:
+ The `scroll-padding` properties (Firefox bug 1373832)
+ The `scroll-margin` properties (Firefox bug 1373833)
+ `scroll-snap-align` (Firefox bug 1373835)
* The `-webkit-line-clamp` property has been implemented for compatibility with other browsers (Firefox bug 866102).
* Support has been added for the `::marker` pseudo-element (Firefox bug 205202) and animation for `::marker` pseudos (Firefox bug 1538618)
* We changed `currentcolor` to be a computed value (except for the `color` property) (Firefox bug 760345).
* Support has been fixed for the `ch` length unit so it now matches the spec (fallback for no '0' glyph, vertical metrics) (Firefox bug 282126)
* The `counter-set` property has been implemented. (Firefox bug 1518201).
* We now implement list numbering using a built-in "list-item" counter; this fixes list numbering bugs (Firefox bug 288704).
* Selector matching and parsing support has been implemented for `::part()` (Firefox bug 1545430) and (Firefox bug 1545425).
* CSS Transforms are now supported in indirectly rendered things e.g.) `<mask>`, `<marker>`, `<pattern>`, `<clipPath>` (Firefox bug 1323962).
* While we're keeping the prefixed versions of the various gradient properties (`gradient/linear-gradient()`, `gradient/radial-gradient()`, and `gradient/repeating-radial-gradient()` available for compatibility reasons, we have revised how they're parsed so that they're handled much more like the non-prefixed versions. This means that certain existing styles won't work correctly.
In particular, the complicated syntax taking both an angle and a position will no longer work, and the `to` keyword in the `<side-or-corner>` parameter is not required for the prefixed gradient properties. You are encouraged to use the standard, non-prefixed gradient properties instead, as they're now widely supported (Firefox bug 1547939).
#### Removals
* `scroll-snap-coordinate`, `scroll-snap-destination`, `scroll-snap-type-x` and `scroll-snap-type-y` have been removed.
* The `scroll-snap-type` property has become a longhand, so the old shorthand syntax like `scroll-snap-type:mandatory` will stop working.
### SVG
*No changes.*
### JavaScript
* The new `BigInt` primitive is enabled by default (Firefox bug 1527902).
* String generic methods have been removed (Firefox bug 1222552).
### APIs
#### CSS Object Model (CSSOM)
* The legacy `rules` property and `addRule()` and `removeRule()` methods have been added to the `CSSStyleSheet` interface. These were introduced by Internet Explorer 9 and have never managed to quite be stamped out, so they have been added to improve compatibility with the small percentage of sites that still use them (Firefox bug 1545823).
#### DOM
* The Visual Viewport API has now been enabled by default on Android (Firefox bug 1512813). Adding this API to desktop versions of Firefox is being tracked in Firefox bug 1551302.
* The `Window` feature `noreferrer` is now supported; if specified, the new window's content is loaded without sharing the hostname, IP address, URL, or other identifying information about the host device (Firefox bug 1527287).
* The `decode()` method on `HTMLImageElement` is now implemented. This can be used to trigger loading and decoding of an image prior to adding it to the DOM (Firefox bug 1501794).
* `XMLHttpRequest` has been updated to no longer accept the non-standard `moz-chunked-arraybuffer` value for `responseType`. Code still using it should be updated to use the Fetch API as a stream (Firefox bug 1120171).
* `XMLHttpRequest` now outputs a warning to console if you perform a synchronous request while handling an `unload`, `beforeunload`, or `pagehide` event (Firefox bug 980902).
* The `cookie` property has moved from the `HTMLDocument` interface to the `Document` interface, allowing documents other than HTML to use cookies (Firefox bug 144795).
* The `HTMLElement.focus()` and `SVGElement.focus()` methods now accept an optional object that may contain a boolean `preventScroll` option specifying whether or not to block the browser from scrolling the newly-focused element into view (Firefox bug 1374045).
#### DOM events
* Firefox for Android no longer incorrectly sends a `resize` event until after the first frame is painted; this improves web compatibility with sites that don't expect this event to occur (Firefox bug 1528052).
* The dispatching of events for non-primary mouse buttons has been made to more closely follow the specification; the `click` event is no longer sent when non-primary buttons are clicked, instead using `auxclick`. In addition, `dblclick` no longer fires for non-primary buttons (Firefox bug 1379466).
* The proprietary `mozPressure` property has been deprecated, and will now trigger a warning in the console (Firefox bug 1165211).
#### Media, Web Audio, and WebRTC
* Due to changes in the Google Play store's policies, starting with Firefox 68 for Android, the OpenH264 codec used to handle AVC/H.264 video in WebRTC connections can no longer be downloaded and installed. Therefore, fresh installs of Firefox on Android devices no longer support AVC in WebRTC calls. If you upgrade from earlier versions of Firefox and already have the codec downloaded, it will continue to work. This does *not* affect other platforms. For more details, see this article on SUMO or Firefox bug 1548679.
* WebRTC has been updated to recognize that a `null` candidate passed into the `icecandidate` event handler, indicating the receipt of a candidate, instead indicates that there are no further candidates coming; when this happens the ICE gathering (`iceGatheringState`) state reaches `complete` (Firefox bug 1318167).
* The `RTCRtpReceiver` methods `getContributingSources()` and `getSynchronizationSources()` now support video tracks; previously they only worked on audio (Firefox bug 1534466).
* The Web Audio API `MediaStreamTrackAudioSourceNode` interface is now supported, as is the method `AudioContext.createMediaStreamTrackSource()` (Firefox bug 1324548).
* `RTCDataChannel.negotiated` is now implemented (Firefox bug 1529695).
* The `MediaStreamAudioSourceNode()` constructor has been updated to match the current specification's definition that the "first audio track" in the stream is the track whose ID comes first in lexicographical order (Firefox bug 1324548).
* `getUserMedia()` may no longer be used from a non-secure context; attempting to do so now throws a `NotAllowedError` exception. Secure contexts are those loaded using HTTPS, those located using the `file:///` scheme, and those loaded from `localhost`. For now, if you must, you can re-enable the ability to perform insecure calls to `getUserMedia()` by setting the preference `media.getusermedia.insecure.enabled` to `true` (Firefox bug 1335740).
**Note:** In the future, Firefox will also remove the `navigator.mediaDevices` property on insecure contexts, preventing all access to the `MediaDevices` APIs. **This is already the case in Nightly builds.**
#### Removals
* Removed the non-standard `XMLDocument.load()` method (Firefox bug 332175).
* Removed the non-standard `XMLDocument.async` property (Firefox bug 1328138).
* The `RTCIceServer.credentialType` `token` value has been removed (Firefox bug 1529595).
### HTTP
* The HTTP `Clear-Site-Data` header no longer supports the `executionContexts` directive. This was removed due to problems with interactions between interconnections among different kinds of data at different points in the navigation process and the way the specification is designed. It has been proposed that this directive be removed from the specification for this reason, among others (Firefox bug 1548034).
#### Removals
* The `Content-Security-Policy` directive `require-sri-for` is no longer supported due to concerns about its standardization status. It was previously available only behind a preference, which was off by default (Firefox bug 1386214).
### Security
* Due to CVE-2019-11730: Same-origin policy treats all files in a directory as having the same-origin, changes have been made so that Firefox now treats files in the same directory as being from different origins. This has a number of side-effects on what will work in documents loaded via file:// URLs (see Firefox bug 1558299 for useful background research). For example, workers can no longer be loaded.
### WebDriver conformance (Marionette)
#### Bug fixes
* If `WebDriver:SwitchToWindow` changes the selection to a different window it now waits for its `focus` and `activate` events before returning (Firefox bug 1335085).
* Fixed the `TypeError: this.tabModal is null` failure, which sometimes appeared when interacting with modal dialogs or user prompts (Firefox bug 1538782)
#### Other
* Disabled the feature to force unloading background tabs on low memory conditions, to prevent top-level browser contexts from magically disappearing (Firefox bug 1553748).
* Disabled privileged content processes that caused HTTP authentication dialogs not to appear when navigating to a website after opening a new tab (Firefox bug 1558763).
### Plugins
*No changes.*
Changes for add-on developers
-----------------------------
### API changes
* The `proxy.register()` and `proxy.unregister()` functions have been deprecated and will be removed from Firefox 71 (Firefox bug 1545811).
* A `boolean` flag, `incognito`, has been added to the proxy.RequestDetails. object. When `true`, it indicates that this was a private browsing request (Firefox bug 1545163).
* The webRequest.RequestFilter parameters can include an incognito parameter. If provided, requests that do not match the incognito state (`true` or `false`) will be filtered out (Firefox bug 1548177).
* A `string` value, `cookieStoreId`, representing the cookie store ID of the current context, has been added to the proxy.RequestDetails. object (Firefox bug 1545420).
* When an add-on attempts to add a bookmark folder to the root folder, the resulting error message is now much more intuitive (Firefox bug 1512171).
* The promise returned by `browser.tabs.duplicate()` now resolves immediately, before the tabs are completely loaded (Firefox bug 1394376).
* Support has been added for chrome.storage.managed, allowing web extension settings to be implemented via enterprise policy (Firefox bug 1230802).
* `proxyAuthorization` and `connectionIsolation` in `proxy.onRequest` now apply only to HTTPS proxies (Firefox bug 1549368.
### Manifest changes
*No changes.*
See also
--------
* Hacks release post: Firefox 68: BigInts, Contrast Checks, and the QuantumBar
Older versions
--------------
* Firefox 67 for developers
* Firefox 66 for developers
* Firefox 65 for developers
* Firefox 64 for developers
* Firefox 63 for developers
* Firefox 62 for developers
* Firefox 61 for developers
* Firefox 60 for developers
* Firefox 59 for developers
* Firefox 58 for developers
* Firefox 57 for developers
* Firefox 56 for developers
* Firefox 55 for developers
* Firefox 54 for developers
* Firefox 53 for developers
* Firefox 52 for developers
* Firefox 51 for developers
* Firefox 50 for developers
* Firefox 49 for developers
* Firefox 48 for developers
* Firefox 47 for developers
* Firefox 46 for developers
* Firefox 45 for developers
* Firefox 44 for developers
* Firefox 43 for developers
* Firefox 42 for developers
* Firefox 41 for developers
* Firefox 40 for developers
* Firefox 39 for developers
* Firefox 38 for developers
* Firefox 37 for developers |
Firefox 122 for developers - Mozilla | Firefox 122 for developers
==========================
This article provides information about the changes in Firefox 122 that affect developers. Firefox 122 is the current Beta version of Firefox and ships on January 23, 2024.
Changes for web developers
--------------------------
### Developer Tools
### HTML
* `<hr>` elements are now allowed as children of `<select>` elements. This is a new feature that improves the readability of select lists with many options. (Firefox bug 1830909).
* The `type` HTML attribute no longer has an effect if set to `none`, `disc`, `circle` or `square` in `<ol>` and no longer has an effect if set to `1`, `a`, `A`, `i` or `I` in `<ul>`. As `type` is a deprecated attribute for `<ul>` and `<ol>` lists, these should be styled with `list-style-type` CSS property instead. (Firefox bug 1868087).
#### Removals
### CSS
* The CSS `offset-position` property is now available by default. It defines the initial position of an element on a path. (Firefox bug 1598152)
* The various methods for defining a CSS `offset-path` — including `<basic-shape>`, `<coord-box>`, and `url()` — are now enabled by default. (Firefox bug 1598159)
* The CSS `ray()` function is now available by default. You can use this function to define an `offset-path` as a line segment that begins from an `offset-position` and extends in the direction of the specified angle. (Firefox bug 1598151)
* The `clip-path` and `offset-path` properties now accept `rect()` and `xywh()` shape functions. These `<basic-shape>` values allow the clipping and offsetting of elements with a rectangle defined by distance from the edge of the element (`rect()`) or coordinates and size (`xywh()`). (Firefox bug 1868722).
#### Removals
### JavaScript
* The `ArrayBuffer.prototype.transfer()` and `ArrayBuffer.prototype.transferToFixedLength()` methods can now be used to transfer ownership of memory from one `ArrayBuffer` to another. After transfer, the original buffer is detached from its original memory and hence unusable; the state can be checked using `ArrayBuffer.prototype.detached`. (See Firefox bug 1865103 for more details.)
#### Removals
### SVG
#### Removals
* Removed support for `data:` URLs in SVG `<use>` elements and via the `SVGUseElement` interface to prevent XSS attacks.
The legacy functionality may be re-enabled by setting the `svg.use-element.data-url-href.allowed` preference to `true`, although this is not recommended for security reasons (Firefox bug 1806964).
### HTTP
#### Removals
### Security
#### Removals
### APIs
* The LargestContentfulPaint API is now supported.
This API is part of the Performance APIs and provides timing information about the largest image or text paint before users interact with a web page (Firefox bug 1866266).
#### DOM
### showPicker() method for HTML select elements
* The `HTMLSelectElement.showPicker()` method is now supported, allowing the browser picker for a `<select>` element to be programmatically launched when triggered by user interaction (Firefox bug 1865207).
#### Media, WebRTC, and Web Audio
#### Removals
### WebAssembly
#### Removals
### WebDriver conformance (WebDriver BiDi, Marionette)
#### General
* Fixed a bug that prevented Perform Actions to correctly synthesize double and other multi-click events for the `mouse` input source (Firefox bug 1864614). Additionally, these events will only be emitted when the actual mouse position has not changed since the last click action (Firefox bug 1681076).
* The definitions for the `Pause` and `Equal` (Numpad block) keys have been updated to align with the WebDriver specification (Firefox bug 1863687).
#### WebDriver BiDi
* The serialization of `WindowProxy` remote objects now also works correctly for out-of-process iframes (Firefox bug 1867667).
* The browsingContext.setViewport command now distinguishes between `undefined` and `null` as values for the `viewport` argument. If set to `undefined`, it signifies that the viewport should remain unchanged, while using `null` will reset it to its original dimensions (Firefox bug 1865618).
* Support for the browsingContext.traverseHistory command has been introduced, enabling navigations backward and forward in the browser history (Firefox bug 1841018).
* Fixed a bug in all supported network events where the `context` id consistently reported the top-level browsing context, even when the navigation occurred within an iframe (Firefox bug 1869735).
#### Marionette
* Fixed a bug with Get Element Text, where the command was incorrectly returning an empty text when the element was located within a ShadowRoot's slot (Firefox bug 1824664).
Changes for add-on developers
-----------------------------
### Removals
### Other
Experimental web features
-------------------------
These features are newly shipped in Firefox 122 but are disabled by default. To experiment with them, search for the appropriate preference on the `about:config` page and set it to `true`. You can find more such features on the Experimental features page.
* **Declarative shadow DOM:** `dom.webcomponents.shadowdom.declarative.enabled`.
The `<template>` element now supports a `shadowrootmode` attribute which can be set to either `open` or `closed`, the same values as the `mode` option of the `attachShadow()` method. It allows the creation of a shadow DOM subtree declaratively. (Firefox bug 1712140)
* **Popover API:** `dom.element.popover.enabled`.
Displaying popovers on top of page content is now supported via HTML attributes or JavaScript API, including styling with the CSS `:popover-open` pseudo-class and extended support for the `::backdrop` pseudo-element. See the Popover API reference for more details. (Firefox bug 1823757)
* **Clipboard read and write:** `dom.events.asyncClipboard.clipboardItem`, `dom.events.asyncClipboard.readText` and `dom.events.asyncClipboard.writeText`.
The async `Clipboard API` is now fully supported, including `read()`, `readText()`, and `write()` methods and the `ClipboardItem` interface. A paste context menu will appear for the user to confirm when reading clipboard data not provided by the same-origin page. (Firefox bug 1809106)
* **`Intl.Segmenter`:** enabled by default only in Firefox Nightly.
The `Intl.Segmenter` object allows accurate locale-sensitive text segmentation of a string. For example, to split a text into words in a language that doesn't use spaces to separate them: `Intl.Segmenter("ja-JP", { granularity: "word" })`. (Firefox bug 1423593)
Older versions
--------------
* Firefox 121 for developers
* Firefox 120 for developers
* Firefox 119 for developers
* Firefox 118 for developers
* Firefox 117 for developers
* Firefox 116 for developers
* Firefox 115 for developers
* Firefox 114 for developers
* Firefox 113 for developers
* Firefox 112 for developers
* Firefox 111 for developers
* Firefox 110 for developers
* Firefox 109 for developers
* Firefox 108 for developers
* Firefox 107 for developers
* Firefox 106 for developers
* Firefox 105 for developers
* Firefox 104 for developers
* Firefox 103 for developers
* Firefox 102 for developers
* Firefox 101 for developers
* Firefox 100 for developers
* Firefox 99 for developers
* Firefox 98 for developers
* Firefox 97 for developers
* Firefox 96 for developers
* Firefox 95 for developers
* Firefox 94 for developers
* Firefox 93 for developers
* Firefox 92 for developers
* Firefox 91 for developers |
Firefox 81 for developers - Mozilla | Firefox 81 for developers
=========================
This article provides information about the changes in Firefox 81 that will affect developers. Firefox 81 was released on September 22, 2020.
Changes for web developers
--------------------------
### Developer Tools
* The Debugger now uses the TypeScript icon for `.ts` and `.tsx` files (Firefox bug 1642769). Previously a generic file icon was used.
* We've added support for line wrapping in the Debugger source pane (Firefox bug 1590885).
* We've removed unnecessary color vision simulations (protanomaly, deuteranomaly, and tritanomaly) from the Accessibility Inspector, and added a simulation for achromatopsia (no color) (Firefox bug 1655053).
* Autocompletion is now supported when adding a class to an element. Offered classes are based on existing classes in the document (Firefox bug 1492797).
### HTML
* Automatic downloads are now blocked in a sandboxed `<iframe>` element (Firefox bug 1558394).
#### Removals
* Support for the non-standard `mozallowfullscreen` attribute has been removed from `<iframe>`. Consider using `allow="fullscreen"` instead (Firefox bug 1657599).
### CSS
* We now support the value of `clip` for the `overflow` property, via renaming `overflow: -moz-hidden-unscrollable` (Firefox bug 1531609).
* The `text-combine-upright` property has been made non-animatable to comply with the spec (Firefox bug 1654195).
#### Removals
* The non-standard `::-moz-focus-outer` pseudo-element has been removed (Firefox bug 1655859).
### JavaScript
*No changes.*
### HTTP
* Firefox now accepts non-standard `Content-Disposition` headers with an unquoted filename containing spaces (Firefox bug 1440677).
* Firefox now supports the HTTP `Feature-Policy` header's `web-share` directive, which can be used to restrict access to the Web Share API to trusted origins. Note that Firefox does not support the Web Share API itself, at time of writing (Firefox bug 1653199).
### APIs
#### Gamepad
* The threshold for gamepad joystick activation has been increased. This reduces the chance of inadvertent gamepad activation, both from controllers that send small axis values when they are idle, and very small bumps. (Firefox bug 1539178)
#### Workers/Service workers
* Strict MIME type checks are now enforced on worker and shared worker scripts, i.e. scripts targeted by the `Worker()` and `SharedWorker()` constructors must now be served with `text/javascript` (Firefox bug 1569123).
### WebDriver conformance (Marionette)
* The `setWindowRect` capability is now `true` by default for all desktop applications (including Thunderbird), and `false` on Android for GeckoView (Firefox bug 1650872).
* We've added Fission support for the following commands: `WebDriver:SwitchToFrame`, `WebDriver:SwitchToParentFrame`, `WebDriver:GetCurrentURL`. All Fission-compatible commands are only available when `marionette.actors.enabled` is set to `true`.
* Fixed the broken tracking of browsing contexts after opening a new window (Firefox bug 1661495).
* In case of failures `WebDriver:SwitchToWindow` now always returns a unified `NoSuchWindowError` (Firefox bug 1663429).
#### Removals
* `WebDriver:GetActiveFrame` has been removed, because it's not part of the WebDriver specification and is no longer used (Firefox bug 1659502).
Changes for add-on developers
-----------------------------
* `tabs.saveAsPDF()` is now supported on macOS (Firefox bug 1653354).
* The behavior of `webNavigation.getFrame()` and `webNavigation.getAllFrames()` has changed. Moving forward, when a tab is discarded the promise will fulfill with a `null` value (Firefox bug 1654842).
Older versions
--------------
* Firefox 80 for developers
* Firefox 79 for developers
* Firefox 78 for developers
* Firefox 77 for developers
* Firefox 76 for developers
* Firefox 75 for developers
* Firefox 74 for developers
* Firefox 73 for developers
* Firefox 72 for developers
* Firefox 71 for developers
* Firefox 70 for developers
* Firefox 69 for developers
* Firefox 68 for developers
* Firefox 67 for developers
* Firefox 66 for developers
* Firefox 65 for developers
* Firefox 64 for developers
* Firefox 63 for developers
* Firefox 62 for developers
* Firefox 61 for developers
* Firefox 60 for developers
* Firefox 59 for developers
* Firefox 58 for developers
* Firefox 57 for developers
* Firefox 56 for developers
* Firefox 55 for developers
* Firefox 54 for developers
* Firefox 53 for developers
* Firefox 52 for developers
* Firefox 51 for developers
* Firefox 50 for developers |
Firefox 41 for developers - Mozilla | Firefox 41 for developers
=========================
To test the latest developer features of Firefox, install Firefox Developer Edition Firefox 41 was released on September 22, 2015. This article lists key changes that are useful not only for web developers, but also Firefox and Gecko developers as well as add-on developers.
Changes for Web developers
--------------------------
### Developer Tools
Highlights:
* Take a screenshot of a DOM node
* Copy as HAR/save as HAR
* "Add Rule" button in the Rules view
* View source in a tab (Disabled by default)
* More options to copy CSS rules
* Copy image as data: URL in the Rules view
* Added command to *GCLI* to display CSP info
All devtools bugs fixed between Firefox 40 and Firefox 41: note that many of these bugs, especially those relating to the performance tools, were uplifted to Firefox 40.
### CSS
* Support for laying out vertical scripts has been activated by default (Firefox bug 1138384). That means that the following CSS properties are now available:
+ Choosing the direction of writing: `writing-mode`.
+ Controlling orientation of characters: `text-orientation`.
+ Direction-independent equivalents of `width` and `height`: `block-size` and `inline-size`.
+ Direction-independent equivalents of `min-width` and `min-height`: `min-block-size` and `min-inline-size`.
+ Direction-independent equivalents of `max-width` and `max-height`: `max-block-size` and `max-block-size`.
+ Direction-independent equivalents of `margin-top`, `margin-right`, `margin-bottom` and `margin-left`: `margin-block-start`, `margin-block-end`, `margin-inline-start` and `margin-inline-end`.
+ Direction-independent equivalents of `padding-top`, `padding-right`, `padding-bottom` and `padding-left`: `padding-block-start`, `padding-block-end`, `padding-inline-start` and `padding-inline-end`.
+ Direction-independent equivalents of `border-top`, `border-right`, `border-bottom` and `border-left` and their longhands for width, style and color: `border-block-start`, `border-block-start-width`, `border-block-start-style`, `border-block-start-color`, `border-block-end`, `border-block-end-width`, `border-block-end-style`, `border-block-end-color`, `border-inline-start`, `border-inline-start-width`, `border-inline-start-style`, `border-inline-start-color`, `border-inline-end`, `border-inline-end-width`, `border-inline-end-style` and `border-inline-end-color`.
+ Direction-independent equivalents of `top`, `right`, `bottom` and `left`: `offset-block-start`, `offset-block-end`, `offset-inline-start` and `offset-inline-end`.
* Support the `transform-origin` property in SVG and implement the `transform-box` property (Firefox bug 923193).
### HTML
* `<a>` without an `href` attribute is no longer classified as interactive content. Clicking it inside `<label>` will activate labelled content (Firefox bug 1167816).
* SVG icons are now supported for site icons, that is favicons and shortcut icons (Firefox bug 366324).
* The `crossorigin` attribute is now supported for <link rel='preconnect'> (Firefox bug 1174152).
* The picture element does not react to resize/viewport changes (Firefox bug 1135812).
### JavaScript
* `Date.prototype` is now an ordinary object, not a `Date` instance anymore (Firefox bug 861219).
* `Date.prototype.toString` is now a generic method (Firefox bug 861219).
* `Symbol.species` has been added (Firefox bug 1131043).
* `Map[@@species]` and `Set[@@species]` getters have been added (Firefox bug 1131043).
* Non-standard let expression support has been dropped (Firefox bug 1023609).
* Destructured parameters with default value assignment are now supported (Firefox bug 1018628).
* Per ES2015, curly braces are required for method definitions. Syntax without them will fail from now on (Firefox bug 1150855).
* Method definitions (except for generator methods) are not constructable anymore (Firefox bug 1059908 and Firefox bug 1166950).
* As part of ES2015 specification compliance, parenthesized destructuring patterns, like `([a, b]) = [1, 2]` or `({a, b}) = { a: 1, b: 2 }`, are now considered invalid and will throw a `SyntaxError`. See Jeff Walden's blog post for more details.
* The `new.target` syntax has been added (Firefox bug 1141865).
### Interfaces/APIs/DOM
#### HTML Editing API
* Cut, copy and paste commands handling has been revamped and now allow programmatic copying and cutting from JS for Web content:
+ With the `'paste'` command as argument, `Document.queryCommandSupported()` now returns `false` if has insufficient privileges to actually perform the action (Firefox bug 1161721).
+ With the `'cut'` or `'copy'` command as argument, `Document.queryCommandSupported()` now returns `true` if called within the context of a user-initiated or privileged code (Firefox bug 1162952).
+ With the `'cut'` or `'copy'` command as argument, `Document.execCommand()` now works, but only within the context of user-initiated or privileged code (Firefox bug 1012662).
+ Instead of raising an exception, `Document.execCommand()` when the command is not supported or enabled (Firefox bug 1027560).
#### Events
* The non-standard `initCloseEvent()` method of the `CloseEvent` event and the ability to create a `CloseEvent` using the `document.createEvent('CloseEvent')` method has been removed; use the standard constructor, `CloseEvent()` instead (Firefox bug 1161950).
* On Desktop, `PointerEvent` is now activated by default in Nightly; it is not activated in Developer Edition, Beta or Release and won't be for at least some versions (Firefox bug 1166347).
* The unprefixed version of `MouseEvent.movementX` and `MouseEvent.movementY` have been added; the prefixed versions are deprecated and will be removed at some point in the future (Firefox bug 1164981).
#### Web Crypto
* `SubtleCrypto.importKey()` and `SubtleCrypto.exportKey()` now supports `ECDH` keys (Firefox bug 1050175).
#### Canvas API
* `HTMLCanvasElement.captureStream()` and `CanvasCaptureMediaStream` have been added and allow to stream the display of a `<canvas>` in real-time (Firefox bug 1032848).
* `MediaStream.id` now returns the unique id of a stream (Firefox bug 1089798).
* The initial value of `CanvasRenderingContext2D.filter` is now correctly set to `none` (Firefox bug 1163124).
#### Service Workers
* Improvement to our experimental Service Worker implementation:
+ `ServiceWorkerGlobalScope.skipWaiting()` has been implemented (Firefox bug 1131352).
+ `Clients.claim()` has been added (Firefox bug 1130684).
+ The other functional events of Service Workers have been made to inherit from `ExtendableEvent`, giving them access to the `waitUntil()` method (Firefox bug 1160527).
* The `CacheStorage` and `Cache` interfaces are now supported (Firefox bug 1110144).
#### WebGL
* The `failIfMajorPerformanceCaveat` WebGL context attribute has been added and can be set when creating a WebGL context with `HTMLCanvasElement.getContext()` to indicate if a context creation should fail if the system performance is low (Firefox bug 1164970).
#### WebRTC
* Firefox no longer offers a default STUN server to be used if none are specified when constructing a new `RTCPeerConnection`. You'll need to provide one in order to successfully establish a WebRTC connection.
#### Miscellaneous
* On OS X and Windows, `Navigator.onLine` now changes regarding network connectivity (it always returned `true`, unless "Work offline" mode was selected) before (Firefox bug 654579).
* `MessagePort` and `MessageChannel` now available in Web workers, and are enabled by default in all contexts (Firefox bug 952139) and (Firefox bug 911972).
* The User Timing API is now available in Web workers (Firefox bug 1155761).
* The Notifications API is now available in Web workers (Firefox bug 916893).
* `DOMRequest` and `DOMCursor` are now available in Web workers (Firefox bug 1167650).
* The CSS Font Loading API has been completely implemented and is now enabled by default (Firefox bug 1149381).
* Shared workers can no longer be shared between private (i.e., browsing in a private window) and non-private documents (see Firefox bug 1177621).
* The `URL.searchParams` property is now read-only (Firefox bug 1174731).
* The `HTMLAnchorElement.hash` property no longer decodes URL fragment (Firefox bug 1093611).
### MathML
#### New default and fallback font handling
Mathematical formulas require special fonts. So far, these fonts were hard-coded in the `mathml.css` user agent stylesheet (which sets the font-family on `<math>` tag) and in the preference option `font.mathfont-family` (which sets the fallback fonts to use for stretchy and large operators). Firefox 41 introduces an internal `x-math` language that is automatically set on the `<math>` tag as well as corresponding preference options (e.g., `font.name.serif.x-math`). The user agent stylesheet now sets font-family to serif on the `<math>` tag and the preference option `font.mathfont-family` is replaced with `font.name.serif.x-math`. All platforms now essentially use the same list of fallback fonts, with "Latin Modern Math" as the first one. The default/fallback fonts can be configured from the standard per-language font preference menu. For more details, see Firefox bug 947654 and Firefox bug 1160456.
### SVG
* Site icons (favicons, shortcut icons) now support SVG (Firefox bug 366324).
### Audio/Video
* The `media.autoplay.enabled` preference now also applies to untrusted `HTMLMediaElement.play()` invocations too, that is calls from non-users activated scripts (Firefox bug 659285).
Networking
----------
* The `X-Content-Duration` header is no longer supported (Firefox bug 1160695).
* Draft versions of the HTTP/2 protocol are no more supported (Firefox bug 1132357).
Security
--------
* The CSP 1.1 `manifest-src` directive is now supported (Firefox bug 1089255).
* Previous versions of Firefox incorrectly expected the Content Security Policy referrer directive's value `origin-when-cross-origin` to be spelled `origin-when-crossorigin`. This has been corrected to include the missing dash character.
Changes for add-on and Mozilla developers
-----------------------------------------
### XUL
*No change.*
### JavaScript code modules
*No change.*
### XPCOM
### Interfaces
*No change.*
### Other
* A new, internal, and chrome-context-only API to render the root widget of a window into a `<canvas>` has been added: `CanvasRenderingContext2D.drawWidgetAsOnScreen()`. This API uses the operating system to snapshot the widget on-screen. For more details see Firefox bug 1167477.
Older versions
--------------
* Firefox 40 for developers
* Firefox 39 for developers
* Firefox 38 for developers
* Firefox 37 for developers
* Firefox 36 for developers
* Firefox 35 for developers
* Firefox 34 for developers
* Firefox 33 for developers
* Firefox 32 for developers
* Firefox 31 for developers
* Firefox 30 for developers
* Firefox 29 for developers
* Firefox 28 for developers
* Firefox 27 for developers
* Firefox 26 for developers
* Firefox 25 for developers
* Firefox 24 for developers
* Firefox 23 for developers
* Firefox 22 for developers
* Firefox 21 for developers
* Firefox 20 for developers
* Firefox 19 for developers
* Firefox 18 for developers
* Firefox 17 for developers
* Firefox 16 for developers
* Firefox 15 for developers
* Firefox 14 for developers
* Firefox 13 for developers
* Firefox 12 for developers
* Firefox 11 for developers
* Firefox 10 for developers |
Firefox 99 for developers - Mozilla | Firefox 99 for developers
=========================
This article provides information about the changes in Firefox 99 that will affect developers. Firefox 99 was released on April 5, 2022.
Changes for web developers
--------------------------
### HTML
No notable changes.
### CSS
No notable changes.
### JavaScript
No notable changes.
### APIs
* `navigator.pdfViewerEnabled` is now enabled, and is the recommended way to determine whether a browser supports inline display of PDF files when navigating to them.
Sites that use the deprecated properties `navigator.plugins` and `navigator.mimeTypes` to infer PDF viewer support should now use the new property, even though these now return hard-coded mock values that match the signal provided by `pdfViewerEnabled` (Firefox bug 1720353).
#### Media, WebRTC, and Web Audio
* The `RTCPeerConnection.setConfiguration()` method is now supported.
Among other things, this allows sites to adjust the configuration to changing network conditions (Firefox bug 1253706).
#### Removals
* The Network Information API was previously enabled on Android (only), but is now disabled by default on all platforms.
This API is on the path for removal because it exposes a significant amount of user information that might be used for fingerprinting.
(Firefox bug 1637922).
### WebDriver conformance (Marionette)
* Fixed a bug where the Shift key was not handled properly when part of a key sequence of the `WebDriver:ElementSendKeys` command (Firefox bug 1757636).
Changes for add-on developers
-----------------------------
Older versions
--------------
* Firefox 98 for developers
* Firefox 97 for developers
* Firefox 96 for developers
* Firefox 95 for developers
* Firefox 94 for developers
* Firefox 93 for developers
* Firefox 92 for developers
* Firefox 91 for developers
* Firefox 90 for developers
* Firefox 89 for developers
* Firefox 88 for developers
* Firefox 87 for developers
* Firefox 86 for developers
* Firefox 85 for developers
* Firefox 84 for developers
* Firefox 83 for developers
* Firefox 82 for developers
* Firefox 81 for developers
* Firefox 80 for developers
* Firefox 79 for developers
* Firefox 78 for developers
* Firefox 77 for developers
* Firefox 76 for developers
* Firefox 75 for developers
* Firefox 74 for developers
* Firefox 73 for developers
* Firefox 72 for developers
* Firefox 71 for developers
* Firefox 70 for developers
* Firefox 69 for developers
* Firefox 68 for developers |
Firefox 70 for developers - Mozilla | Firefox 70 for developers
=========================
This article provides information about the changes in Firefox 70 that will affect developers. Firefox 70 was released on October 22, 2019.
Changes for web developers
--------------------------
### Developer tools
#### Debugger updates
* In the Debugger you can now set breakpoints for DOM Mutation, so execution will pause when a node or its attributes are changed or when a node is removed from the DOM (Firefox bug 1576219).
* The Debugger now shows an overlay on the page when it is paused, with basic stepping buttons to let you step and continue (Firefox bug 1574646).
* The Debugger now shows sources that already got discarded by the engine (usually scripts that execute once during page load), so you can properly set breakpoints to debug when they execute next (Firefox bug 1572280).
* The Debugger's scopes panel grouping has been simplified, consolidating additional scopes previously shown above the top level function (e.g. blocks created by `let`, `with`, or `if`/`else`) (Firefox bug 1448166)
* The Debugger now retains the currently selected and expanded variables in the scopes panel while stepping (Firefox bug 1405402).
* The Debugger now handles stepping over async functions correctly, making asynchronous function debugging easier (Firefox bug 1570178).
* When debugging in Container sessions (useful for testing different logins), the sources in the debugger are now shown correctly (Firefox bug 1375036).
* `debugger` statements can be now disabled in the Debugger by setting a breakpoint on them and switching the breakpoints to "Never pause here" (Firefox bug 925269).
* WebExtensions developers can inspect `browser.storage.local` from the Extension Storage item under the Storage tab (Firefox bug 1585499).
#### Other updates
* An icon will be displayed next to inactive CSS properties in the Rules view of the Page Inspector, which you can hover over to get information on why it is inactive (Firefox bug 1306054).
* In the CSS Rules view, the color picker on foreground colors now tells you whether its contrast with the background color meets accessibility conformance criteria (Firefox bug 1478156).
* The Accessibility inspector's Check for issues dropdown now includes keyboard accessibility checks (Firefox bug 1564968).
### HTML
* Firefox can now suggest securely-generated passwords to the user in the following situations:
+ An `<input>` element has the `autocomplete="new-password"` attribute value.
+ The user opens the context menu on any password input element, even if it is not intended for new passwords.
### CSS
* Opacity values like for `opacity` or `stop-opacity` can now be percentages (Firefox bug 1562086).
* `grid-auto-columns` and `grid-auto-rows` now accept multiple track-size values (Firefox bug 1339672).
* A number of text-related CSS properties have been enabled by default (Firefox bug 1573631):
+ `text-decoration-thickness`.
+ `text-underline-offset`.
+ `text-decoration-skip-ink`. The default value is `auto`, which means that by default underlines and overlines are now interrupted where they would otherwise cross over a glyph.
* The `display` property now accepts two keyword values representing the inner and outer display type (Firefox bug 1038294, Webkit bug 1105868 and Webkit bug 1557825).
* The `font-size` property now accepts the new keyword value `xxx-large`. (Firefox bug 1553545).
* The `:visited` pseudo-class no longer matches `<link>` elements, for logic and performance reasons (Firefox bug 1572246; see Intent to ship: Make <link> elements always unvisited and [selectors] :link and <link> for more reasoning as to why).
* We now support an `auto` value for the `quotes` property (Firefox bug 1421938).
* Stylesheets contained in `<style>` elements are now cached for reuse, to improve performance (Firefox bug 1480146). Note that this currently doesn't include stylesheets that contain `@import` rules.
* The `<ratio>` type now accepts `<number>/<number>` or a single `<number>` as a value. (Firefox bug 1565562).
#### Removals
* We have retired support for 3-valued <position> (excluding background)(Firefox bug 1559276).
* The `none` value is now invalid in `counter()` / `counters()` — a change which makes the Level 3 spec match CSS 2.1 Firefox bug 1576821).
### SVG
* Cut, copy, and paste events are now dispatched to SVG graphics elements (Firefox bug 1569474).
### MathML
* The deprecated `mode` attribute on `<math>` elements has been removed (Firefox bug 1573438).
* Non-zero unitless length values, such as `5` for `500%`, are no longer supported.
* Length values ending with a dot, such as `2.` or `34.px`, are also unsupported now.
### JavaScript
* Numeric separators are now supported (Firefox bug 1435818).
* The `Intl.RelativeTimeFormat.formatToParts()` method has been implemented (Firefox bug 1473229).
* The `BigInt.prototype.toLocaleString()` method has been updated to work with the `locales` and `options` parameters per the ECMAScript 402 Intl API. Also, `Intl.NumberFormat.format()` and `Intl.NumberFormat.formatToParts()` now accept `BigInt` values (Firefox bug 1543677).
* Per the latest ECMAScript specification, a leading zero is now never allowed for BigInt literals, making `08n` and `09n` invalid similar to the existing error when legacy octal numbers like `07n` are used. Always use a leading zero with the letter "o" (lowercase or uppercase) for octal `BigInt` numbers (i.e. `0o755n` instead of `0755n`). See Firefox bug 1568619.
* The Unicode extension key "nu" is now supported for the `Intl.RelativeTimeFormat` constructor and the `Intl.RelativeTimeFormat.resolvedOptions()` method now also returns `numberingSystem` (Firefox bug 1521819).
### APIs
#### DOM
* The `back()`, `forward()`, and `go()` methods are now asynchronous. Add a listener to the `popstate` event to get notification that navigation has completed Firefox bug 1563587.
* We've added support `DOMMatrix`, `DOMPoint`, etc. in web workers (Firefox bug 1420580).
* A few more members have been moved from `HTMLDocument` to `Document`, including `Document.all`, `Document.clear`, `Document.captureEvents`, and `Document.clearEvents` (Firefox bug 1558570, Firefox bug 1558571).
* Notification permission can no longer be requested from inside a cross-origin `<iframe>` (Firefox bug 1560741).
#### Media, Web Audio, and WebRTC
* The `RTCPeerConnection.restartIce()` method has been added. This is one of the four changes needed to implement the new "perfect negotiation" mechanism; the rest will come in future Firefox updates (Firefox bug 1551316).
* The `RTCPeerConnection.setRemoteDescription()` method can now be called with no parameters. This is another "perfect negotiation" update (Firefox bug 1568292).
* `MediaTrackSupportedConstraints.groupId` is now supported, and returns `true` since the `MediaTrackConstraints.groupId` property is now supported (Firefox bug 1561254).
* Several new Web Audio API features have been implemented/updated:
+ `AudioContext.getOutputTimestamp()` implemented (Firefox bug 1324545).
+ `AudioContext.baseLatency` and `AudioContext.outputLatency` implemented (Firefox bug 1324552).
+ `MediaElementAudioSourceNode.mediaElement` and `MediaStreamAudioSourceNode.mediaStream` implemented (Firefox bug 1350973).
+ The `ChannelMergerNode()` constructor now throws errors if you try to set `channelCount` and `channelCountMode` to invalid values (Firefox bug 1456263).
#### Canvas and WebGL
* We now support `CanvasRenderingContext2D.getTransform()`, and the newer variant of `CanvasRenderingContext2D.setTransform()` that accepts a matrix object as a parameter rather than multiple parameters representing the individual components of the matrix (Firefox bug 928150).
### HTTP
* The default referrer policy for third-party tracking resources is now `strict-origin-when-cross-origin` when Enhanced Tracking Protection is turned on (Firefox bug 1569996).
* The size of the `Referer` request header is now limited to 4 KB (4,096 bytes). If an overly long referer exceeds the defined limit, only the origin part will be sent (Firefox bug 1557346).
* The HTTP cache is now partitioned per the top-level document's origin (Firefox bug 1536058).
#### Removals
* The `X-Frame-Options` `allow-from uri` directive has been removed. Use the `Content-Security-Policy` header with the `frame-ancestors` directive instead (Firefox bug 1301529).
### WebDriver conformance (Marionette)
* Updated the `WebDriver:TakeScreenshot` command to be Fission compatible. It means that content from cross-origin iframes is now included in a page's screenshot. Or when using it from chrome scope that the active tab's content is visible now inside the browser window. (Firefox bug 1559592).
* `WebDriver:TakeScreenshot` no longer accepts a list of DOM elements as used for highlighting (Firefox bug 1575511).
* `WebDriver:ExecuteScript` and `WebDriver:ExecuteAsyncScript` no longer sets `window.onunload` in ways that are web-exposed (Firefox bug 1568991).
Changes for add-on developers
-----------------------------
### API changes
* Added a new parameter to the `topSites.get()` method that causes the method to return the list of pages that appear when the user opens a new tab (Firefox bug 1568617).
* The `privacy.network` property's `WebRTCIPHandlingPolicy` sub-property's permitted values have been amended (in Firefox bug 1452713) to match the behavior seen in Chrome as follows:
+ `disable_non_proxied_udp` previously prevented the use of WebRTC if no proxy was configured. Now a proxy is always used if one is configured, but otherwise a non-proxied connection is permitted.
+ `proxy_only` can be used to provide the old behavior; this has the effect of only allowing ICE negotiation over TURN on TCP using a proxy; no other connections are allowed.
### Manifest changes
#### Removals
The following theme key properties, which provided aliases for theme keys used in chromium-based browsers, were removed:
* `images` property `headerURL`, themes should now use `theme_frame`.
* `colors` properties:
+ `accentcolor`, themes should now use `frame`.
+ `textcolor`, themes should now use `tab_background_text`.
See also
--------
* Hacks release post: Firefox 70 — a bountiful release for all
Older versions
--------------
* Firefox 69 for developers
* Firefox 68 for developers
* Firefox 67 for developers
* Firefox 66 for developers
* Firefox 65 for developers
* Firefox 64 for developers
* Firefox 63 for developers
* Firefox 62 for developers
* Firefox 61 for developers
* Firefox 60 for developers
* Firefox 59 for developers
* Firefox 58 for developers
* Firefox 57 for developers
* Firefox 56 for developers
* Firefox 55 for developers
* Firefox 54 for developers
* Firefox 53 for developers
* Firefox 52 for developers
* Firefox 51 for developers
* Firefox 50 for developers
* Firefox 49 for developers
* Firefox 48 for developers
* Firefox 47 for developers
* Firefox 46 for developers
* Firefox 45 for developers
* Firefox 44 for developers
* Firefox 43 for developers
* Firefox 42 for developers
* Firefox 41 for developers
* Firefox 40 for developers
* Firefox 39 for developers |
Firefox 35 for developers - Mozilla | Firefox 35 for developers
=========================
Firefox 35 was released on January 13th, 2015. This article lists key changes that are useful not only for web developers, but also Firefox and Gecko developers as well as add-on developers.
Changes for Web developers
--------------------------
### Developer Tools
Highlights:
* See ::before and ::after pseudo elements in the Page Inspector
* CSS source maps are now enabled by default
* "Show DOM Properties" from the Page Inspector
All devtools bugs fixed between Firefox 34 and Firefox 35.
### CSS
* The `mask-type` property has been activated by default (Firefox bug 1058519).
* The `filter` property is now activated by default (Firefox bug 1057180).
* The `@font-face` at-rule now supports WOFF2 fonts (Firefox bug 1064737).
* The `symbols()` functional notation is now supported (Firefox bug 966168).
* The CSS Font Loading API has been implemented (Firefox bug 1028497).
* Using `-moz-appearance` with the `none` value on a combobox now remove the dropdown button (Firefox bug 649849).
* The property accessor `element.style["css-property-name"]` has been added to match other browsers (Firefox bug 958887).
### HTML
* The obsolete and non-conforming `bottommargin`, `leftmargin`, `rightmargin` and `topmargin` attributes of the `<body>` element have been activated in non-quirks mode (Firefox bug 95530).
### JavaScript
* The "temporal dead zone" for `let` declarations has been implemented. In conformance with ES2015 `let` semantics, the following situations now throw errors. See also this newsgroup announcement and Firefox bug 1001090.
+ Redeclaring existing variables or arguments using `let` within the same scope in function bodies is now a syntax error.
+ Using a variable declared using `let` in function bodies before the declaration is reached and evaluated is now a runtime error.
* ES2015 `Symbols` (only available in the Nightly channel) have been updated to conform with recent specification changes:
+ `String(Symbol("1"))` now no longer throws a `TypeError`; instead a string (`"Symbol(1)"`) gets returned (Firefox bug 1058396).
* The various *TypedArray* constructors now have as their `[[Prototype]]` a single function, denoted `%TypedArray%` in ES2015 (but otherwise not directly exposed). Each typed array prototype now inherits from `%TypedArray%.prototype`. (`%TypedArray%` and `%TypedArray%.prototype` inherit from `Function.prototype` and `Object.prototype`, respectively, so that typed array constructors and instances still have the properties found on those objects.) Typed array function properties now reside on `%TypedArray%.prototype` and work on any typed array. See *TypedArray* and Firefox bug 896116 for more information.
* ES2015 semantics for prototype mutations using object literals have been implemented (Firefox bug 1061853).
+ Now only a single member notated as `__proto__:value` will mutate the `[[Prototype]]` in the object literal syntax.
+ Method members like `__proto__() {}` will not overwrite the `[[Prototype]]` anymore.
### Interfaces/APIs/DOM
* `navigator.language` and `navigator.languages` are now available to workers on `WorkerNavigator` (Firefox bug 925849).
* The `Element.closest()` method returns the closest ancestor of the current element (Firefox bug 1055533).
* Experimental support for the `CanvasRenderingContext2D.filter` property has been added behind the `canvas.filters.enabled` flag (Firefox bug 927892).
* Our experimental implementation of Web Animations progresses with the landing of the `Animation.target` property. This always is behind the `dom.animations-api.core.enabled` pref, off by default (Firefox bug 1067701).
* The `hasAttributes()` method has been moved from `Node` to `Element` as required by the spec (Firefox bug 1055773).
* The `crossOrigin` reflected attribute of `HTMLImageElement`, `HTMLLinkElement`, `HTMLMediaElement`, `HTMLScriptElement`, and `SVGScriptElement` only accepts valid values, and `""` isn't, `null` has to be used instead (Firefox bug 880997).
* The Resource Timing API has been activated by default (Firefox bug 1002855).
* To match the spec, the first argument of `Selection.containsNode()` cannot be `null` anymore (Firefox bug 1068058).
* The new `ImageCapture` API has been implemented: `ImageCapture.takePhoto()` is available (Firefox bug 916643).
* Non-HTTP `XMLHttpRequest` requests now return `200` in case of success (instead of the erroneous `0`) (Firefox bug 716491).
* `XMLHttpRequest.responseURL` has been adapted to the latest spec and doesn't include the fragment (`'#xyz'`) of the URL, if relevant (Firefox bug 1073882).
* The internal, non-standard, `File.mozFullPath` property is no more visible from content (Firefox bug 1048293).
* The constructor of `File` has been extended to match the specification (Firefox bug 1047483).
* An experimental implementation of `AbortablePromise`, a promise that can be aborted by a different entity that the one who created it, has been added. It is prefixed with `Moz` and controlled by the `dom.abortablepromise.enabled` property, defaulting to `false` (Firefox bug 1035060).
* The non-standard `Navigator.mozIsLocallyAvailable` property has been removed (Firefox bug 1066826).
* The preference `network.websocket.enabled`, `true` by default, has been removed; Websocket API cannot be deactivated anymore (Firefox bug 1091016).
* The non-standard methods and properties of `Crypto` have been removed (Firefox bug 1030963). Only methods and properties defined in the standard WebCrypto API are left.
* Our experimental implementation of WebGL 2.0 is going forward!
+ The `WebGL2RenderingContext.copyBufferSubData()` method has been implemented (Firefox bug 1048668).
### MathML
* The `dtls` OpenType feature (via the CSS `font-feature-settings` on the default stylesheet) is now applied automatically to MathML elements when positioning scripts over it (e.g. dotless i with mathematical hat).
### SVG
*No change.*
### Audio/Video
*No change.*
Network & Security
------------------
* HTTP/2 has been implemented and activated, with AEAD ciphers only (Firefox bug 1027720 and Firefox bug 1047594).
* The HTTP/2 `alt-svc` header is now supported (Firefox bug 1003448).
* The Public Key Pinning Extension for HTTP (HPKP) has been implemented (Firefox bug 787133).
* The CSP 1.1 `base-uri` directive is now supported (Firefox bug 1045897).
* Path of the source is now considered too when host-source matching happens in CSP (Firefox bug 808292).
Changes for add-on and Mozilla developers
-----------------------------------------
### XUL & Add-ons
* The private `_getTabForBrowser()` method on the `<xul:tabbrowser>` element has been deprecated. In its place, we've added a new, public, method called `getTabForBrowser`. This returns, predictably, the `<xul:tab>` element that contains the specified `<xul:browser>`.
* `Components.utils.now()`, matching `Performance.now()` has been implemented for non-window chrome code (Firefox bug 969490).
### Add-on SDK
#### Highlights
* Added access keys for context menu.
* Removed `isPrivateBrowsing` from `BrowserWindow`.
* Added `toJSON` method to `URL` instances.
#### Details
GitHub commits made between Firefox 34 and Firefox 35. This will not include any uplifts made after this release entered Aurora.
Bugs fixed between Firefox 34 and Firefox 35. This will not include any uplifts made after this release entered Aurora.
Older versions
--------------
* Firefox 34 for developers
* Firefox 33 for developers
* Firefox 32 for developers
* Firefox 31 for developers
* Firefox 30 for developers
* Firefox 29 for developers
* Firefox 28 for developers
* Firefox 27 for developers
* Firefox 26 for developers
* Firefox 25 for developers
* Firefox 24 for developers
* Firefox 23 for developers
* Firefox 22 for developers
* Firefox 21 for developers
* Firefox 20 for developers
* Firefox 19 for developers
* Firefox 18 for developers
* Firefox 17 for developers
* Firefox 16 for developers
* Firefox 15 for developers
* Firefox 14 for developers
* Firefox 13 for developers
* Firefox 12 for developers
* Firefox 11 for developers
* Firefox 10 for developers
* Firefox 9 for developers
* Firefox 8 for developers
* Firefox 7 for developers
* Firefox 6 for developers
* Firefox 5 for developers
* Firefox 4 for developers
* Firefox 3.6 for developers
* Firefox 3.5 for developers
* Firefox 3 for developers
* Firefox 2 for developers
* Firefox 1.5 for developers |
Firefox 97 for developers - Mozilla | Firefox 97 for developers
=========================
This article provides information about the changes in Firefox 97 that affect developers. Firefox 97 was released on February 8, 2022.
Changes for web developers
--------------------------
### HTML
No notable changes
### CSS
* The CSS units `cap` and `ic` are now supported for use with `<length>` and `<length-percentage>` data types.
For more information, see Firefox bug 1702924 and Firefox bug 1531223.
* The CSS property `color-adjust` has been renamed to `print-color-adjust` to match the relevant specification.
The `color-adjust` shorthand name is deprecated.
See Firefox bug 747595 for details.
* CSS cascade layers are now available by default. The `@layer` rule declares a cascade layer, which allows declaration of styles and can be imported via the `@import` rule using the `layer()` function. See Firefox bug 1699217 for more details.
* The global CSS keyword `revert-layer` has been added to allow rolling back of property values in one cascade layer to the matching rules in the previous cascade layer. This keyword can be applied on any property, including the CSS shorthand property `all`. For more information, see Firefox bug 1699220.
* The CSS `scrollbar-gutter` property is now supported. This gives developers control over reserved space for the scrollbar, preventing unwanted layout changes as the content grows.
See Firefox bug 1715112 for more details.
### JavaScript
No notable changes
### SVG
* The SVG `d` attribute, used to define a path to be drawn, can now be used as a property in CSS.
It accepts the values path() or `none`. (See Firefox bug 1744599 for details.)
#### Removals
* A number of `SVGPathSeg` APIs are now disabled by default behind a preference, and are expected to be removed in future revisions.
This includes: `SVGPathSegList`, SVGPathElement.getPathSegAtLength(), `SVGAnimatedPathData`.
(See Firefox bug 1388931 for more details.)
### APIs
* `AnimationFrameProvider` is now available in a `DedicatedWorkerGlobalScope`. This means the `requestAnimationFrame` and `cancelAnimationFrame` methods can be used within a dedicated worker.
(See Firefox bug 1388931 for more details.)
#### DOM
* The reason for an abort signal can now be set using `AbortController.abort()` (or `AbortSignal.abort()`), and will be available in the `AbortSignal.reason` property.
This reason defaults to being an "AbortError" `DOMException`.
The reason can be thrown or handled via promise rejection as appropriate.
(Firefox bug 1737771).
* The convenience method `AbortSignal.throwIfAborted()` can be used to check if a signal has been aborted, and if so throw the `AbortSignal.reason()`.
This makes it easier for developers to handle abort signals in code where you can't simply pass the signal to an abortable method. (Firefox bug 1745372).
### WebDriver conformance (Marionette)
* `Marionette:Quit` accepts a new boolean parameter, `safeMode`, to restart Firefox in safe mode (Firefox bug 1144075).
* Improved stability for `WebDriver:NewSession` and `WebDriver:NewWindow` when waiting for the current or initial document to be loaded (Firefox bug 1739369, Firefox bug 1747359).
Changes for add-on developers
-----------------------------
* `cookieStoreId` in `tabs.query` supports an array of strings. This enables queries to match tabs against more than one cookie store ID (Firefox bug 1730931).
* `cookieStoreId` added to `contentScripts.register`. This enables extensions to register container-specific content scripts (Firefox bug 1470651).
Older versions
--------------
* Firefox 96 for developers
* Firefox 95 for developers
* Firefox 94 for developers
* Firefox 93 for developers
* Firefox 92 for developers
* Firefox 91 for developers
* Firefox 90 for developers
* Firefox 89 for developers
* Firefox 88 for developers
* Firefox 87 for developers
* Firefox 86 for developers
* Firefox 85 for developers
* Firefox 84 for developers
* Firefox 83 for developers
* Firefox 82 for developers
* Firefox 81 for developers
* Firefox 80 for developers
* Firefox 79 for developers
* Firefox 78 for developers
* Firefox 77 for developers
* Firefox 76 for developers
* Firefox 75 for developers
* Firefox 74 for developers
* Firefox 73 for developers
* Firefox 72 for developers
* Firefox 71 for developers
* Firefox 70 for developers
* Firefox 69 for developers
* Firefox 68 for developers
* Firefox 67 for developers
* Firefox 66 for developers |
Firefox 105 for developers - Mozilla | Firefox 105 for developers
==========================
This article provides information about the changes in Firefox 105 that affect developers. Firefox 105 was released on September 20, 2022.
Changes for web developers
--------------------------
### HTML
No notable changes.
### CSS
* Embedded content, such as SVG definitions and content in an `<iframe>`, now respects the theme preferences of the elements in which it is embedded, rather than OS or browser preferences (which may be different).
Specifically, embedded content now inherits the `color-scheme` of the embedding element, and `prefers-color-scheme` media queries in the embedded content respect this value rather than the OS/browser level theme setting (Firefox bug 1779457).
### JavaScript
* Range restrictions have been relaxed on `formatRange` and `selectRange` functions for `Intl.DateTimeFormat`, `Intl.NumberFormat`, and `Intl.PluralRules` objects. This change now allows negative ranges (Firefox bug 1780545).
### APIs
#### DOM
* The TextDecoderStream and TextEncoderStream interfaces, part of the Encoding API, are now supported (Firefox bug 1486949).
* The OffscreenCanvas API provides a canvas that can be rendered off-screen in both window and web worker contexts.
This allows `<canvas>` elements to be decoupled from the DOM. The OffscreenCanvasRenderingContext2D interface provides support for this and is now enabled by default (Firefox bug 1779009).
* The CSS Font Loading API can now be used in worker threads (Firefox bug 1072107).
### WebDriver conformance (WebDriver BiDi, Marionette)
#### WebDriver BiDi
* On systems with IPv6 preferred DNS resolution clients will no longer fail to connect when `localhost` is used as host for the WebSocket server (Firefox bug 1769994).
* Improved `RemoteValue` support to allow plain JS objects with simple JSON-serializable fields to be serialized (Firefox bug 1779226).
#### Marionette
* The `WebDriver:GetElementProperty` command is now able to return node properties as set by web content (Firefox bug 1398792).
Changes for add-on developers
-----------------------------
* Support for defining persistent scripts using `scripting` has been added. A script is identified as persistent using the `persistAcrossSessions` property in `scripting.RegisteredContentScript` (Firefox bug 1751436).
* An extension's resources can no longer be loaded by other extensions by default. To enable other extensions to load resources they must be listed in the extension's `web_accessible_resources` manifest key (Firefox bug 1711168).
Older versions
--------------
* Firefox 104 for developers
* Firefox 103 for developers
* Firefox 102 for developers
* Firefox 101 for developers
* Firefox 100 for developers
* Firefox 99 for developers
* Firefox 98 for developers
* Firefox 97 for developers
* Firefox 96 for developers
* Firefox 95 for developers
* Firefox 94 for developers
* Firefox 93 for developers
* Firefox 92 for developers
* Firefox 91 for developers
* Firefox 90 for developers
* Firefox 89 for developers
* Firefox 88 for developers
* Firefox 87 for developers
* Firefox 86 for developers
* Firefox 85 for developers
* Firefox 84 for developers
* Firefox 83 for developers
* Firefox 82 for developers
* Firefox 81 for developers
* Firefox 80 for developers
* Firefox 79 for developers
* Firefox 78 for developers
* Firefox 77 for developers
* Firefox 76 for developers
* Firefox 75 for developers
* Firefox 74 for developers |
Firefox 66 for developers - Mozilla | Firefox 66 for developers
=========================
This article provides information about the changes in Firefox 66 that will affect developers. Firefox 66 was released on March 19, 2019.
Changes for web developers
--------------------------
### Developer tools
* JavaScript getters can now be executed from the auto-completion popup in the Web Console (Firefox bug 1499289).
* The Window methods `alert()`, `prompt()`, and `confirm()` now work again in Responsive Design Mode, after a period of being broken (Firefox bug 1273997).
* You can copy the output of the console to the clipboard by right-clicking and selecting "**Export visible messages to clipboard**" from the context menu.
### HTML
* UTF-8-encoded HTML (and plain text) files loaded from `file:` URLs are now supported without `<meta charset="utf-8">` or the UTF-8 BOM, making it easier to work on such files locally before uploading them to a server. You still need to make sure that the server sends `charset=utf-8` in the `Content-Type` HTTP header for such files, otherwise the detection mechanism used for local files would break incremental loading in the network case (Firefox bug 1071816).
#### Removals
* The `x-moz-errormessage` attribute has been removed from the `<input>` element (Firefox bug 1513890). You should use the constraint validation API to implement custom validation messages instead.
### CSS
* Scroll anchoring has been implemented in Firefox Desktop (but not mobile yet), which includes the `overflow-anchor` property (Firefox bug 1305957).
* We've implemented the case-sensitive attribute selector modifier, `s` (Firefox bug 1512386).
* Several logical property shorthands have landed, along with the flow-relative border radius properties:
+ `padding-block` and `padding-inline` (Firefox bug 1519847).
+ `margin-block` and `margin-inline` (Firefox bug 1519944).
+ `inset`, `inset-block`, and `inset-inline` (Firefox bug 1520229).
+ `border-block-color`, `border-block-style`, `border-block-width`, `border-inline-color`, `border-inline-style`, and `border-inline-width` (Firefox bug 1520236).
+ `border-block` and `border-inline` (Firefox bug 1520396).
+ `border-start-start-radius`, `border-start-end-radius`, `border-end-start-radius`, and `border-end-end-radius` (Firefox bug 1520684).
* We implemented the `overflow-inline` and `overflow-block` media queries (Firefox bug 1422235).
* `grid-template-columns` and `grid-template-rows` are now animatable, as per the rules set out in their specs (Firefox bug 1348519).
* We now support `calc()` with percentages for table cells and column widths (Firefox bug 957915).
* The `min-content` and `max-content` keywords are now available unprefixed (Firefox bug 1322780). These can be set on:
+ `width`
+ `height`
+ `flex-basis`
+ `min-width`
+ `max-width`
+ `min-height`
+ `max-height`
+ `min-block-size`
+ `min-inline-size`
+ `max-block-size`
+ `max-inline-size`
+ `block-size`
+ `inline-size`
### SVG
*No additions.*
#### Removals
* We removed support for the `xml:base` attribute (Firefox bug 903372).
### JavaScript
No changes.
### APIs
#### New APIs/changes
* Autoplaying audio will be blocked by default soon after 66 becomes the release version of Firefox (Firefox bug 1487844, see Firefox bug 1535667 for rollout details). The feature will be rolled out gradually to users until everyone has it.
#### DOM
* The `HTMLSlotElement.assignedElements()` method has been implemented (Firefox bug 1425685).
* The `TextEncoder.encodeInto()` method has been implemented (Firefox bug 1514664).
#### DOM events
* The `InputEvent.inputType` property has been implemented (Firefox bug 1447239).
* The `Window.event` and `Event.returnValue` properties — originally proprietary IE features, then also supported across other browsers for compatibility purposes — have been re-introduced in Firefox 66, after first being added in versions 63 and 64 respectively but then removed again due to compatibility issues.
* From 66 onwards, when the `KeyboardEvent.keyCode` property of the `keypress` event object is 0, the value will be the same as `KeyboardEvent.charCode`. Conversely, when `charCode` is 0, it will be the same as `keyCode`. This mirroring behavior matches other browsers and is expected to solve most associated compatibility issues, however user agent sniffing might cause further issues in some JavaScript libraries. Note that in spec terms, we've switched from the *split model* to the *conflated model* (see How to determine keyCode for keypress events in the UI Event spec).
#### Media, Web Audio, and WebRTC
* The new AV1 video codec is now enabled by default on both macOS and Windows (for Intel processors). Linux support will come in Firefox 67 (Firefox bug 1521181, Firefox bug 1452146, and Firefox bug 1534814).
* The `MediaDevices` method `getDisplayMedia()`, available as `navigator.mediaDevices.getDisplayMedia()`, has been added and synchronized with the specification. This method lets you capture a screen or part of a screen as a `MediaStream` for manipulation or sharing (Firefox bug 1321221).
* As a step toward eventually deprecating the Firefox-specific `getUserMedia()`-based method for capturing screen and window contents, the non-standard `mediaSource` constraint now treats the values `screen` and `window` identically. Both now present a list of both screens and windows for the user to choose from (Firefox bug 1474376).
* `qpSum` has been added to local outbound `RTCRTPStreamStats` objects. This measures the total of the Quantization Parameter values for every frame sent or received on the video track. The higher this number, the more compressed the stream probably is (Firefox bug 1347070).
* In a step along the road toward implementing support for Feature Policy in a future Firefox update, `getUserMedia()` can no longer be used in situations in which there is no proper origin for the content, such as when called from a sandboxed `<iframe>` or from a `data` URL entered into the address bar by the user. For more details, see the Security section on the MediaDevices.getUserMedia() page (Firefox bug 1371741).
#### Removals
* The legacy WebRTC `PeerConnection.getStats()` method has been removed, along with associated types (Firefox bug 1328194).
### Networking
* The default value of the `Accept` header has been changed to `*/*` (Firefox bug 1417463).
### Security
*No changes.*
### Plugins
*No changes.*
### WebDriver conformance (Marionette)
#### API changes
* `WebDriver:NewWindow` has been added to support opening of a new browsing context, which can be one of either window or tab (Firefox bug 1504756).
* `WebDriver:SwitchToFrame` now raises a `no such element` error if the specified element isn't part of the current browsing context (Firefox bug 1517196).
* `WebDriver:ExecuteScript` and `WebDriver:ExecuteAsyncScript` no longer support the non-spec compliant `scriptTimeout` parameter. Instead, use `WebDriver:SetTimeout` or the `timeouts` capability to define this value (Firefox bug 1510929).
+ In addition, indefinite script timeouts are now supported (Firefox bug 1128997).
* `WebDriver:SetWindowRect` no longer returns the window state in its response (Firefox bug 1517587).
#### Bug fixes
* `WebDriver:TakeScreenshot` now uses the `Element.clientWidth` and `Element.clientHeight` properties of the `Document.documentElement` instead of the viewport dimensions (Firefox bug 1385706).
* Various fixes have been applied to make window manipulation commands more reliable across platforms (Firefox bug 1522408, Firefox bug 1478358, Firefox bug 1489955).
Changes for add-on developers
-----------------------------
### API changes
#### Menus
* Extension menu items of the "bookmark" `type` will also appear in the Bookmarks sidebar (`Ctrl` + `B`) and Library window (`Ctrl` + `Shift` + `B`) (Firefox bug 1419195).
### Manifest changes
*No changes.*
See also
--------
* Hacks release post: Firefox 66: The Sound of Silence
Older versions
--------------
* Firefox 65 for developers
* Firefox 64 for developers
* Firefox 63 for developers
* Firefox 62 for developers
* Firefox 61 for developers
* Firefox 60 for developers
* Firefox 59 for developers
* Firefox 58 for developers
* Firefox 57 for developers
* Firefox 56 for developers
* Firefox 55 for developers
* Firefox 54 for developers
* Firefox 53 for developers
* Firefox 52 for developers
* Firefox 51 for developers
* Firefox 50 for developers
* Firefox 49 for developers
* Firefox 48 for developers
* Firefox 47 for developers
* Firefox 46 for developers
* Firefox 45 for developers
* Firefox 44 for developers
* Firefox 43 for developers
* Firefox 42 for developers
* Firefox 41 for developers
* Firefox 40 for developers
* Firefox 39 for developers
* Firefox 38 for developers
* Firefox 37 for developers
* Firefox 36 for developers
* Firefox 35 for developers |
Firefox 57 (Quantum) for developers - Mozilla | Firefox 57 (Quantum) for developers
===================================
This article provides information about the changes in Firefox 57 (a.k.a. Firefox Quantum) that will affect developers. Firefox 57 was released on November 14, 2017.
Firefox 57 === Firefox Quantum
------------------------------
Firefox 57 has been given the release name **Quantum**, after the Firefox Quantum engineering project that has aimed to rebuild Firefox from the ground up, bringing with it major performance, stability, and visual improvements. This is the first version of Firefox to ship some of these improvements, so we wanted to mark the occasion.
**Note:** To read more about the Quantum features in this release, see Firefox Quantum Developer Edition: the fastest Firefox ever with Photon UI and better tooling by Dan Callahan.
Firefox's new parallel CSS engine — also known as **Quantum CSS** or **Stylo** — is enabled by default in Firefox 57 for desktop, with Mobile versions of Firefox to follow later on. Developers shouldn't notice anything significantly different, aside from a whole host of performance improvements. There are however a number of minor functional differences in Stylo, implemented to fix non-standard Gecko behavior that should be eliminated. We will report on such differences on reference pages and in the release notes as appropriate (see Quantum CSS notes).
Changes for Web developers
--------------------------
### Developer Tools
*No changes.*
### HTML
* The date and time `<input>` types are now enabled in all builds (Firefox bug 1399036).
### CSS
* The `minimal-ui` and `standalone` values of the `display-mode` media query are now supported (Firefox bug 1369815). See also the Web app manifest `display` field.
* The `grid-row-gap` and `grid-column-gap` properties are no longer reset by the `grid` shorthand (Firefox bug 1387410).
* The `layout.css.clip-path-shapes.enabled` preference has been removed (Firefox bug 1399767). This preference allowed disabling the `<basic-shape>` support in `clip-path`. This support was shipped in Firefox 54 and can no longer be disabled.
#### Quantum CSS notes
Following bugs have been fixed in Quantum:
* Radial gradient values like `radial-gradient(circle gold,red)` will work in the old Gecko style system, even though they shouldn't because of the missing comma between `circle` and `gold` (Firefox bug 1383323).
* When you animate an offscreen element onscreen but specify a delay, Gecko does not repaint on some platforms, e.g. Windows (Firefox bug 1383239).
* In Gecko, `<details>` elements can't be made open by default using the `open` attribute if they have an `animation` active on them (Firefox bug 1382124).
* In Gecko, `transitions` will not work when transitioning from a `text-shadow` with a color specified to a `text-shadow` without a color specified (Firefox bug 726550).
* In Gecko, cancelling a filling animation (e.g. with `animation-fill-mode: forwards` set) can trigger a transition set on the same element, although only once (see Firefox bug 1192592 and these test cases for more information). In general declarative animations should not trigger transitions.
* Animations using em units are not affected by changes to the `font-size` on the animated element's parent in Gecko, whereas they should be (Firefox bug 1254424).
* Gecko also deals with `font-size` inheritance differently from Quantum CSS, meaning that for some language settings inherited font sizes end up being smaller than expected (see Firefox bug 1391341).
* Gecko reuses the same mechanism used when parsing a url-token when parsing the `domain()` or `url-prefix()` URL matching functions for a `@-moz-document` rule. Quantum CSS does not use the same mechanism and it does not consider tokens invalid when they contain brackets or quotes (Firefox bug 1362333).
* In Gecko, when you set a system font as the value of a canvas 2D context's `font` (e.g. `menu`), getting the font value fails to return the expected font (it returns nothing). This has been fixed in Quantum. (Firefox bug 1374885).
* In Gecko, when you create a detached subtree (e.g. a `<div>` created using `createElement()` that is not yet inserted into the DOM), the subtree's root element is set as a block-level element. In Quantum CSS this is set as inline, as per spec (Firefox bug 1374994).
* In Gecko, `calc()` expressions are rejected — causing the value to be invalid — when used as the radius component of a `gradient/radial-gradient()` function (Firefox bug 1376019).
* In Gecko, `calc(1*2*3)` is not parsed successfully; Quantum CSS fixes this (Firefox bug 1379467).
* In Quantum CSS, `calc()` is supported everywhere that the spec explains it should be (Firefox bug 1350857). In Gecko it is not.
* Gecko has a bug whereby the `::before` and `::after` pseudo-elements are still generated even if the `content` property value is set to `normal` or `none`. As per spec, they shouldn't be (Firefox bug 1387931).
* Another Gecko bug means that the `background-position` property can't be transitioned between two values containing different numbers of `<position>` values, for example `background-position: 10px 10px;` and `background-position: 20px 20px, 30px 30px;` (see Firefox bug 1390446).
### SVG
*No changes.*
### JavaScript
* The non-standard `for each...in` loop, originally part of EcmaScript for XML (E4X), has been removed. Please use `for...of` instead and see Warning: JavaScript 1.6's for-each-in loops are deprecated for migration help. (Firefox bug 1083470).
* The `Object.prototype.watch()` and `unwatch()` methods are deprecated, will now throw a warning when used, and will be removed soon (Firefox bug 934669).
* The non-standard `Iterator` and `StopIteration` objects as well as the legacy iteration protocol have been removed (Firefox bug 1098412).
* Async generator is now enabled (Firefox bug 1352312).
* for await (... of ...) syntax is now enabled (Firefox bug 1352312).
### APIs
#### New APIs
* The `PerformanceObserver` API is now enabled by default (Firefox bug 1386021).
* The `AbortController` and `AbortSignal` interfaces (known as the Abort API) have been added, allowing DOM requests (such as fetch requests) to be aborted if desired (Firefox bug 1378342).
* [2] The Storage API is implemented and enabled by default (Firefox bug 1399038).
#### DOM
* The `Selection.type` property of the Selection API is now implemented (Firefox bug 1359157).
* `Document.createEvent('FocusEvent')` is now supported (Firefox bug 1388069).
* The `files` property of the `HTMLInputElement` interface is now settable (Firefox bug 1384030).
* The `HTMLDocument.getSelection()` method has been moved to the `Document` interface so it is available to XML documents (Firefox bug 718711).
* The `messageerror` event is now implemented, and can have code run in response to it firing via event handlers implemented on message targets — see `MessagePort.messageerror_event`, `DedicatedWorkerGlobalScope.messageerror_event`, `Worker.messageerror_event`, `BroadcastChannel.messageerror_event`, and `Window.messageerror_event` (Firefox bug 1359017).
* When `Headers` values are iterated over, they are automatically sorted in lexicographical order, and values from duplicate header names are combined (Firefox bug 1396848).
#### DOM events
*No changes.*
#### Media and WebRTC
* Support for messages of arbitrary size (up to 1GiB, although 256kiB is more interoperable) is now supported on `RTCDataChannel` through use of the end-of-record (EOR) flag on SCTP messages. See Understanding message size limits for more information (Firefox bug 979417).
**Note:** Because Firefox doesn't yet support the SCTP ndata protocol that provides the ability to interleave SCTP messages from multiple sources, sending large data objects can cause significant delays on all other SCTP traffic. See Firefox bug 1381145 to track progress on implementing and deploying ndata support in Firefox.
* The `RTCDataChannel.send()` method can now throw a `TypeError` exception if the size of the message you're trying to send is not compatible with the receiving user agent (this is implemented as part of Firefox bug 979417).
* The MediaStream Recording API has been updated so that `error` events sent to report problems that occur while recording are now of type `MediaRecorderErrorEvent` rather than being generic events.
* Updated the documentation around `OfflineAudioContext` since its constructor's inputs can now be specified in an object rather than as a list of parameters (Firefox bug 1388591).
* The Web Audio API now properly supports multi-channel output (Firefox bug 1378070).
### Security
* `resource://` URLs no longer leak information (Firefox bug 863246)
* Data URLs are now treated as unique opaque origins, rather than inheriting the origin of the settings object responsible for the navigation (Firefox bug 1324406).
### Plugins
*No changes.*
### Other
* Firefox headless mode now includes a `-screenshot` flag that allows you to take website screenshots directly from the command line (Firefox bug 1378010).
Removals from the web platform
------------------------------
### HTML
* `<link rel="preload">` (see Preloading content with rel="preload") has been disabled in Firefox 57 because of various web compatibility issues (e.g. Firefox bug 1405761). An improved version that works for non-cacheable resources is expected to land in Firefox 58.
### APIs
* Mozilla's proprietary Social API has been completely removed (Firefox bug 1388902).
### SVG
*No changes.*
Changes for add-on and Mozilla developers
-----------------------------------------
**Note:** Starting in Firefox 57, all support for XPCOM-based add-ons has been removed. All extensions must be converted into the new browser extensions (also known as WebExtensions) or they will not work.
### WebExtensions
The following APIs have been added or extended:
* `bookmarks`
+ support for separators through `bookmarks.BookmarkTreeNodeType`
* `browser_action`
+ `theme_icons` property for light/dark theme icons
* `browserAction`
+ `browserAction.openPopup()`
* `browserSettings`
+ `allowPopupsForUserEvents`
+ `homepageOverride`
+ `imageAnimationBehavior`
+ `newTabPageOverride`
* `browsingData`
+ `browsingData.removeLocalStorage()`
* `clipboard`
+ `setImageData()`
* `contextualIdentities`
+ `onCreated`
+ `onRemoved`
+ `onUpdated`
+ `colorCode` and `iconUrl` in `contextualIdentities.ContextualIdentity`
* `devtools.panels`
+ `devtools.panels.ElementsPanel.createSidebarPane()`
* `downloads`
+ `incognito` option in `downloads.download()`
+ `estimatedEndTime` property in `downloads.DownloadItem`
* `find`
+ `find()`
+ `highlightResults()`
+ `removeHighlighting()`
* `pageAction.openPopup()`
* `privacy`
+ `websites.trackingProtectionMode`
* `proxy`
+ `FindProxyForURL()` can now return an object
* `runtime`
+ `runtime.openOptionsPage()` support on Android
* `sessions`
+ `setTabValue()`
+ `getTabValue()`
+ `removeTabValue()`
+ `setWindowValue()`
+ `getWindowValue()`
+ `removeWindowValue()`
* `sidebarAction`
+ `sidebarAction.open()`
* `storage`
+ `storage.managed`
* `tabs`
+ `loadReplace` option in `tabs.update()`
+ `discarded` property in `tabs.Tab`, `tabs.onUpdated`, and `tabs.query()`
+ `tabs.create()` can open "view-source:" URLs
+ `openerTabId` property in `tabs.Tab`, `tabs.create()`, `tabs.query()`, and `tabs.update()`
* `theme`
+ `colors.toolbar`
+ `colors.toolbar_field`
+ `colors.toolbar_field_text`
+ `colors.toolbar_text`
* `theme`
+ `windowId` option to `theme.update()`
* `webRequest`
+ `filterResponseData()`
+ `proxyInfo` property in `webRequest` events
* `windows`
+ `allowScriptsToClose` option in `windows.create()`
Older versions
--------------
* Firefox 56 for developers
* Firefox 55 for developers
* Firefox 54 for developers
* Firefox 53 for developers
* Firefox 52 for developers
* Firefox 51 for developers
* Firefox 50 for developers
* Firefox 49 for developers
* Firefox 48 for developers
* Firefox 47 for developers
* Firefox 46 for developers
* Firefox 45 for developers
* Firefox 44 for developers
* Firefox 43 for developers
* Firefox 42 for developers
* Firefox 41 for developers
* Firefox 40 for developers
* Firefox 39 for developers
* Firefox 38 for developers
* Firefox 37 for developers
* Firefox 36 for developers
* Firefox 35 for developers
* Firefox 34 for developers
* Firefox 33 for developers
* Firefox 32 for developers
* Firefox 31 for developers
* Firefox 30 for developers
* Firefox 29 for developers
* Firefox 28 for developers
* Firefox 27 for developers
* Firefox 26 for developers |
Firefox 101 for developers - Mozilla | Firefox 101 for developers
==========================
This article provides information about the changes in Firefox 101 that will affect developers. Firefox 101 was released on May 31, 2022.
Changes for web developers
--------------------------
### HTML
No notable changes.
### CSS
* The `prefers-contrast` media feature that is used to detect whether the user has specified a preference for higher (`more`) or lower (`less`) contrast in the presentation of web content is now available by default. This feature now also lets users specify a set of colors to use for the contrast through the new `custom` value (Firefox bug 1656363).
* Three new viewport sizes have been introduced: small (`s`), large (`l`), and dynamic (`d`). These new sizes have added new viewport-percentage length units in addition to the existing ones - `vh`, `vw`, `vmax`, and `vmin`. The new viewport-percentage length units include `svh`, `lvh`, `dvh`, `svw`, `lvw`, `dvw`, `svmax`, `lvmax`, `dvmax`, `svmin`, `lvmin`, and `dvmin` (Firefox bug 1610815). Additionally, the units `vb` and `vi` are now supported by default (Firefox bug 1610815).
* Support for the `inline-size` value for the `contain` property has been added. For more information, see (Firefox bug 1755565).
### JavaScript
No notable changes.
### APIs
#### DOM
* `HTMLMediaElement.preservesPitch` is now supported without the `moz` prefix.
`mozPreservesPitch` is now an alias of `preservesPitch`, but is deprecated, and may be removed in future releases (Firefox bug 1652950).
* `HTMLInputElement.showPicker()` is now supported, allowing the picker for an input element to be displayed when a user interacts with some other element, such as a button (Firefox bug 1745005).
* `DOMException` is now a serializable object, so it can be cloned with `structuredClone()` or copied between workers using `postMessage()` (Firefox bug 1561357).
* *Constructable stylesheets* are now supported, making it much easier to create reusable stylesheets for use with Shadow DOM.
The update includes the addition of a `CSSStyleSheet()` constructor for creating new stylesheets, the `CSSStyleSheet.replace()` and `CSSStyleSheet.replaceSync()` methods that can be used to add/replace CSS rules in the sheet, and the `Document.adoptedStyleSheets` and `ShadowRoot.adoptedStyleSheets` properties that are used to share sheets to a document and its shadow DOM subtrees.
See Firefox bug 1520690 for more information.
#### Media, WebRTC, and Web Audio
* AV1 codec parameters are now properly parsed in media support queries.
This means that `MediaCapabilities.decodingInfo()`, `HTMLMediaElement.canPlayType()`, and `MediaSource.isTypeSupported()` will now accurately report support for playback for AV1 sources based on the provided codec parameters.
`MediaCapabilities.decodingInfo()` will also use the information to accurately report on "efficient decoding" of AV1 videos.
For more information, see Firefox bug 1757861.
* `maxFramerate` is now supported for setting the maximum framerate that can be used to send an encoding (in `RTCPeerConnection.addTransceiver()` and `RTCRtpSender.setParameters()`).
Note that zero if a valid frame rate value, but is interpreted by Firefox as "no frame rate limit".
For more information, see Firefox bug 1611957.
#### SVG
* SVG images in the Firefox UI that are styled using `prefers-color-scheme` will respect the `color-scheme` of the embedder (previously `prefers-color-scheme` ignored the `color-scheme` of the embedder and triggered off either the device or browser theme).
This ensures that a favicon, for example, is always styled to match the theme of the elements that nest it, and not necessarily the (potentially different) theme of the device. (Firefox bug 1764354).
### WebDriver conformance (WebDriver BiDi, Marionette)
Starting with this release of Firefox the WebDriver BiDi protocol will be enabled by default. A WebDriver BiDi session can be requested by using WebDriver classic (geckodriver, Marionette) and setting the `webSocketURL` capability to `true` when creating a new WebDriver session. The same capability will then contain the WebSocket end-point for BiDi clients to connect to.
The following commands and events are available:
* Adds the `session` module including a partial implementation for the commands to globally subscribe (`session.subscribe`) to and unsubscribe (`session.unsubscribe`) from events, and the ability to create a direct WebDriver BiDi session (`session.new`) when not using WebDriver classic.
* Adds the `browsingContext` module including the commands to open a new tab or window (`browsingContext.create`) or close such one (`browsingContext.close`), retrieve open browsing contexts (`browsingContext.getTree`) and to navigate within a browsing context (`browsingContext.navigate`). There is also support for the event when a browsing context got created (`browsingContext.contextCreated`).
* Adds the `log` module including support for log events (`log.entryAdded`).
For more information, see the full bug list.
Changes for add-on developers
-----------------------------
* Addition of the `storage.StorageArea.onChanged` event that enables you to listen for changes in content in the `local` and `sync` storage areas (Firefox bug 1758475).
* Manifest V3 preview features:
+ Addition of the `scripting` API, which provides features to execute a script, insert and remove CSS, and manage the registration of content scripts (Firefox bug 1687764). This API is available to Manifest V3 extensions and takes over the execute script and insert and remove CSS features from the `tabs` API.
+ Addition of the `action` API, which takes over the features of the `browserAction` API in Manifest V3 extensions. Corresponding addition of the `"action"` manifest key and `_execute_action` special shortcut to the manifest `commands` key. Note that the `browserAction` API and `"browser_action"` manifest key are only available in Manifest V2 extensions.
+ The `"background"` manifest key property `"persistent"` can be set to `false` under the control of preferences: for Manifest V2, the `extensions.eventPages.enabled` preference, and in Manifest V3, the `extensions.manifestV3.enabled` preference.
+ Addition of the `"host_permissions"` manifest key, which is available for Manifest V3 extensions.
+ The content script execution environment has changed for Manifest V3 extensions:
- Content scripts can no longer rely on host permissions to perform cross-origin requests. Cross-origin requests from content scripts are possible with CORS.
- The `content` object (that offered `content.fetch`, `content.XMLHttpRequest`, and `content.WebSocket`) is removed from the content script execution environment.
Older versions
--------------
* Firefox 100 for developers
* Firefox 99 for developers
* Firefox 98 for developers
* Firefox 97 for developers
* Firefox 96 for developers
* Firefox 95 for developers
* Firefox 94 for developers
* Firefox 93 for developers
* Firefox 92 for developers
* Firefox 91 for developers
* Firefox 90 for developers
* Firefox 89 for developers
* Firefox 88 for developers
* Firefox 87 for developers
* Firefox 86 for developers
* Firefox 85 for developers
* Firefox 84 for developers
* Firefox 83 for developers
* Firefox 82 for developers
* Firefox 81 for developers
* Firefox 80 for developers
* Firefox 79 for developers
* Firefox 78 for developers
* Firefox 77 for developers
* Firefox 76 for developers
* Firefox 75 for developers
* Firefox 74 for developers
* Firefox 73 for developers
* Firefox 72 for developers
* Firefox 71 for developers
* Firefox 70 for developers |
Firefox 31 for developers - Mozilla | Firefox 31 for developers
=========================
Changes for Web developers
--------------------------
### Developer Tools
Highlights:
* Eyedropper tool to select colors in web pages
* full stack traces for console error messages
* editable Box Model View
* %c formatting to style console messages
* "copy as cURL" command in Network Monitor
* Sublime Text keybindings in the source editor
* Option to make Network Monitor logs persistent
* JavaScript warnings on by default in the Web Console
* Alt+click to expand all descendants of a node
All devtools bugs fixed between Firefox 30 and Firefox 31.
### CSS
* Changed `var-` prefix of CSS Variables to `--` to reflect the final spec change (Firefox bug 985838).
* The `hyphens` property now support Polish hyphenation rules (Firefox bug 987668).
* Removed an unwanted white space for multiple of 10,000 in Korean counter styles (Firefox bug 985186).
* CSS opacity transition broken with parent pseudo :before and overflow auto (Firefox bug 990340).
* The `::-moz-math-stretchy` pseudo-element has been removed (Firefox bug 1000879).
### HTML
* `<track>` has been implemented (Firefox bug 629350).
### JavaScript
New ECMAScript 2015 features implemented:
* New `Array` built-in: `Array.prototype.fill()` (Firefox bug 911147)
* New `Math` function: `Math.clz32()` (Firefox bug 925123)
* New `String` built-in: `String.prototype.normalize()` is available in Firefox Desktop (Firefox bug 918987).
* New `Object` method `Object.setPrototypeOf()`.
* New `Number` constants: `Number.MAX_SAFE_INTEGER` and `Number.MIN_SAFE_INTEGER`.
* The ES2015 Proxy `isExtensible` trap have been implemented (Firefox bug 978235).
### Interfaces/APIs/DOM
* Constructor of `KeyboardEvent` has been implemented (Firefox bug 930893).
* The Resource Timing API has been implemented (see Firefox bug 822480).
* `KeyboardEvent.isComposing` attribute has been implemented (Firefox bug 993234).
* `InputEvent` interface has been implemented (Firefox bug 993253).
* `InputEvent.isComposing` attribute has been implemented (Firefox bug 993253).
* `CSS.escape()` has been implemented (Firefox bug 955860).
* `mousemove` is now cancelable like in other browsers (Firefox bug 704423). Calling `preventDefault()` only sets `defaultPrevented` attribute to `true;` any other behaviors are not changed. E.g., it cannot prevent to set `:hover` state.
* The `Path2D` interface has been implemented.
* The `CanvasRenderingContext2D.isPointInPath()`, `CanvasRenderingContext2D.isPointInStroke()`, `CanvasRenderingContext2D.clip()`, `CanvasRenderingContext2D.fill()` and `CanvasRenderingContext2D.stroke()` methods have been updated to optionally accept a `Path2D` object.
* Implemented `HTMLMediaElement.fastSeek()`.
* The `Connection` interface has been renamed to `NetworkInformation` and has been modified to match the new specification (Firefox bug 960426).
* The `Navigator.sendBeacon()` has been implemented; this allows asynchronous transmission of analytics or other data in a manner that doesn't rely on the transmitting page remaining loaded, so that it can be used in an `unload` or `beforeunload` handler.
### MathML
* Partial implementation of the OpenType MATH table, section 6.3.6 (Firefox bug 407059). For details, try the MathML torture test .
* The `::-moz-math-stretchy` pseudo-element has been removed (Firefox bug 1000879).
* When available, the Unicode Mathematical alphanumeric characters are used for bold, italic and bold-italic math variants (Firefox bug 930504).
### SVG
*No change.*
### Audio/Video
*No change.*
Security
--------
* Privileged code now gets Xray vision for `Date` instances.
Changes for add-on and Mozilla developers
-----------------------------------------
* The "`align`" attribute on the `urlbar-wrapper` (formerly on the `urlbar-container`) which was set to "`center`" since time immemorial, has been removed. This is known to affect third-party themes. You should look carefully at what the right fix is for your theme, but for maintaining the equivalent effect, you can add the following CSS rule to your theme:
```css
#urlbar-wrapper {
-moz-box-align: center;
}
```
* `nsIDOMWindowUtils.sendQueryContentEvent()` and `nsIDOMWindowUtils.sendSelectionSetEvent()` have `aAdditionalFlags` as optional argument. If you called `nsIDOMWindowUtils.sendSelectionSetEvent()` with `true` for `aReverse`, the behavior would be broken by this change. See explanation of each flag (`QUERY_CONTENT_FLAG_*` and `SELECTION_SET_FLAG_*`) for the detail of `aAdditionalFlags`.
### Add-on SDK
Highlights:
* Add-on Debugger
* Added the ability to convert between high-level BrowserWindow objects and DOM windows, and between high-level Tab objects and XUL tabs.
* Updated the default theme used for panels on Mac OS X.
* Added contentStyle and contentStyleFile options to panel.
GitHub commits made between Firefox 30 and Firefox 31. This will not include any uplifts made after this release entered Aurora.
Bugs fixed between Firefox 30 and Firefox 31. This will not include any uplifts made after this release entered Aurora.
### Older versions
* Firefox 30 for developers
* Firefox 29 for developers
* Firefox 28 for developers
* Firefox 27 for developers
* Firefox 26 for developers
* Firefox 25 for developers
* Firefox 24 for developers
* Firefox 23 for developers
* Firefox 22 for developers
* Firefox 21 for developers
* Firefox 20 for developers
* Firefox 19 for developers
* Firefox 18 for developers
* Firefox 17 for developers
* Firefox 16 for developers
* Firefox 15 for developers
* Firefox 14 for developers
* Firefox 13 for developers
* Firefox 12 for developers
* Firefox 11 for developers
* Firefox 10 for developers
* Firefox 9 for developers
* Firefox 8 for developers
* Firefox 7 for developers
* Firefox 6 for developers
* Firefox 5 for developers
* Firefox 4 for developers
* Firefox 3.6 for developers
* Firefox 3.5 for developers
* Firefox 3 for developers
* Firefox 2 for developers
* Firefox 1.5 for developers |
Firefox 93 for developers - Mozilla | Firefox 93 for developers
=========================
This article provides information about the changes in Firefox 93 that will affect developers. Firefox 93 was released on October 5, 2021.
**Note:** See also Lots to see in Firefox 93 on Mozilla Hacks.
Changes for web developers
--------------------------
### HTML
* The ARIA `meter` role has been implemented (Firefox bug 1727616).
* The UI for `<input type="datetime-local">` has been implemented. (Firefox bug 1283388).
### CSS
* The `small-caps` keyword is now supported for the `font-synthesis` property (Firefox bug 1706080).
### JavaScript
* Class `static` initialization blocks are now supported, allowing more flexible initialization of `static` properties (Firefox bug 1725689).
* The properties `imageOrientation` and `premultiplyAlpha` can be passed to the method `createImageBitmap()` using the `options` object (Firefox bug 1367251).
* `Intl.supportedValuesOf()` is now supported, allowing code to enumerate values supported by an implementation, This might be used, for example, to download a polyfill for just the missing category of values (Firefox bug 1670033).
### HTTP
* The SHA-256 algorithm is now supported for HTTP Authentication using digests. This allows much more secure authentication than previously available using the MD5 algorithm (Firefox bug 472823).
* The default HTTP `ACCEPT` header for *images* changed to: `image/avif,image/webp,*/*` (following addition of support for the AVIF image format). (Firefox bug 1682995).
### APIs
* `ElementInternals.shadowRoot` and `HTMLElement.attachInternals` are now supported (Firefox bug 1723521).
* The value `device-pixel-content-box` is now supported for `ResizeObserver.Observe()` (Firefox bug 1587973).
* The `reportError()` global function is now supported, allowing scripts to report errors to the console or global event handlers, emulating an uncaught JavaScript exception (Firefox bug 1722448).
#### Events
* The `onsecuritypolicyviolation` global event handler property is now supported.
This can be used to assign a handler for processing `securitypolicyviolation` events fired when there is a Content Security Policy violation (Firefox bug 1727302).
* The `onslotchange` event handler property is now supported on `HTMLSlotElement` and `ShadowRoot`.
This can be used to assign a handler for processing `slotchange` events, which are fired on `<slot>` elements when the node(s) contained in the slot change (Firefox bug 1501983).
#### Removals
* `KeyboardEvent.initKeyEvent()` has been moved behind the preference `dom.keyboardevent.init_key_event.enabled` and is disabled by default.
The method is not present in any current specification or supported in other current browsers (Firefox bug 1717760).
### WebDriver conformance (Marionette)
* Fixed a bug which caused `WebDriver:Print` to fail for large documents (Firefox bug 1721982).
Changes for add-on developers
-----------------------------
* Sidebars are now included in `extension.getViews` when `windowId` is specified (Firefox bug 1612390).
Other
-----
* Support for AVIF images is now enabled by default (Firefox bug 1682995).
This format has excellent compression and no patent restrictions (it was developed by the Alliance for Open Media).
Firefox can display still images, with colorspace support for both full and limited range colors, and image transforms for mirroring and rotation.
The preference image.avif.compliance\_strictness can be used to adjust the compliance strictness with the specification. Animated images are not supported.
Older versions
--------------
* Firefox 92 for developers
* Firefox 91 for developers
* Firefox 90 for developers
* Firefox 89 for developers
* Firefox 88 for developers
* Firefox 87 for developers
* Firefox 86 for developers
* Firefox 85 for developers
* Firefox 84 for developers
* Firefox 83 for developers
* Firefox 82 for developers
* Firefox 81 for developers
* Firefox 80 for developers
* Firefox 79 for developers
* Firefox 78 for developers
* Firefox 77 for developers
* Firefox 76 for developers
* Firefox 75 for developers
* Firefox 74 for developers
* Firefox 73 for developers
* Firefox 72 for developers
* Firefox 71 for developers
* Firefox 70 for developers
* Firefox 69 for developers
* Firefox 68 for developers
* Firefox 67 for developers
* Firefox 66 for developers
* Firefox 65 for developers
* Firefox 64 for developers
* Firefox 63 for developers
* Firefox 62 for developers |
Firefox 18 for developers - Mozilla | Firefox 18 for developers
=========================
Firefox 18 was released on January 8, 2013. This article lists key changes that are useful not only for web developers, but also Firefox and Gecko developers as well as add-on developers.
Changes for Web developers
--------------------------
### HTML
* The `reversed` attribute of the `<ol>` element is now supported (Firefox bug 601912).
* The `crossorigin` attribute of the `<link>` element is now supported (Firefox bug 786564).
* The `allowfullscreen` attribute of the `<iframe>` has been implemented and it's prefixed predecessor `mozallowfullscreen` is now deprecated.
### CSS
* The `min-width` and `min-height` now uses the `auto` keyword as *initial value* (This has an effect only on flex items as it resolves to `0`, the previous initial value, for other items). (Firefox bug 763689)
* The cascade has been updated: now author `!important` rules override CSS animations. (Firefox bug 783714)
* The `background` shorthand property now recognizes CSS3 `background-size` property specified inside. (Firefox bug 570326)
* Initial support for the CSS Flexbox Module has been landed. It is disabled by default but can be enabled by setting `layout.css.flexbox.enabled` to true (Firefox bug 666041).
### DOM/APIs
* `navigator.mozPay` has been landed. (Firefox bug 767818)
* `window.devicePixelRatio` has been landed. (Firefox bug 564815)
* The MacOS X backend for `window.navigator.battery` has been implemented. (Firefox bug 696045)
* `MozBlobBuilder` is removed. Developers need to use `Blob` constructor for creating a `Blob` object. (Firefox bug 744907)
* The `visibilitychange` event and the Page Visibility API has been unprefixed (Firefox bug 812086).
* `TextDecoder` and `TextEncoder` have been added. Note that the implementation and spec of these evolved and have been changed in Firefox 19 (Firefox bug 764234).
* `HTMLMediaElement.src` has been separate in two properties: the standard `src` property, dealing with strings, and the prefixed `mozSrcObject` property, dealing with media streams (Firefox bug 792665).
* Support for transferable objects.
* The `Screen.lockOrientation()` method now supports an `Array` of strings as argument (Firefox bug 784549.
### JavaScript
* Harmony's (ECMAScript 2015) Direct Proxies have been landed (Firefox bug 703537). Warning: the implementation contains a couple of known bugs, missing features and misalignments with the current state of the spec. Do not rely on it for production code.
* The ECMAScript 2015 `contains()` method is now implemented on strings. This is unfortunately not compatible with Mootools 1.2, which expects different behavior from `contains()` on strings but does not ensure it. Newer versions of Mootools fix this issue; sites should upgrade their Mootools version to something newer than 1.2.
### WebGL
* The prefixed version of the `EXT_texture_filter_anisotropic` WebGL extension, "MOZ\_EXT\_texture\_filter\_anisotropic" has been removed (Firefox bug 790946).
### SVG
### MathML
### XUL
### Network
* Quality factors ("q-values") are now clamped to 2 digits (e.g. in HTTP `Accept-Language` headers) (Firefox bug 672448).
* The `ALLOW-FROM` syntax of the `X-FRAME-OPTIONS` HTTP Response header is now supported (Firefox bug 690168).
### Developer tools
Changes for add-on and Mozilla developers
-----------------------------------------
### Interface changes
`nsIStreamListener`
The 4th parameter (aOffset) of `onDataAvailable()` method changes to unsigned long long. (Firefox bug 784912)
`nsIUploadChannel`
`setUploadStream()` supports over 2GB content-length (Firefox bug 790617)
`nsIEditor`
`addEditorObserver()` has been removed, use `setEditorObserver()` instead, `removeEditorObserver()` no longer takes a `nsIEditorObserver` parameter (Firefox bug 785091)
`nsIHttpProtocolHandler`
`http-on-modify-request` observers are no longer guaranteed to be called synchronously during `nsIChannel.asyncOpen()`.
For observers that need to be called during `asyncOpen()`, the new `http-on-opening-request` observer topic has been added. `See` (Firefox bug 800799)
`nsIProtocolProxyService`
The `resolve` method has been removed. Now, only the `asyncResolve` method can be used. See (Firefox bug 769764)
#### New interfaces
#### Removed interfaces
The following interfaces have been removed.
* `nsIEditorObserver`
See also
--------
* Firefox 18 Beta Release Notes
* Aurora 18: HiDPI & Touch Events (Mozilla Hacks)
* Add-on Compatibility for Firefox 18 (Add-ons Blog)
### Older versions
* Firefox 17 for developers
* Firefox 16 for developers
* Firefox 15 for developers
* Firefox 14 for developers
* Firefox 13 for developers
* Firefox 12 for developers
* Firefox 11 for developers
* Firefox 10 for developers
* Firefox 9 for developers
* Firefox 8 for developers
* Firefox 7 for developers
* Firefox 6 for developers
* Firefox 5 for developers
* Firefox 4 for developers
* Firefox 3.6 for developers
* Firefox 3.5 for developers
* Firefox 3 for developers
* Firefox 2 for developers
* Firefox 1.5 for developers |
Firefox 53 for developers - Mozilla | Firefox 53 for developers
=========================
Firefox 53 was released on April 19, 2017. This article lists key changes that are useful not only for web developers but also for Firefox and Gecko developers, as well as add-on developers.
Changes for Web developers
--------------------------
### Developer Tools
* Avoid scrolling latency on highlighters given by APZ (Firefox bug 1312103).
* Added option to copy the full CSS path of an element (Firefox bug 1323700).
* Devtools support for css-color-4 (Firefox bug 1310681).
* Markup view: add a visual hint between opening and closing tags of a collapsed node (Firefox bug 1323193).
### CSS
#### New features
* The `mask-*` longhand properties (see CSS Masks) are all supported and available by default (see Firefox bug 1251161).
* Added `caret-color` property (Firefox bug 1063162).
* Implemented the `place-items`/`place-self`/`place-content` shorthands (Firefox bug 1319958).
* Added `flow-root` value to `display` property (Firefox bug 1322191).
* `-moz-tab-size` now accepts `<length>` values (Firefox bug 943918), and is now animatable (Firefox bug 1308110).
* `mask-mode`:luminance doesn't work on gradient masks (Firefox bug 1346265).
* [css-grid] FR Unit in `grid-template-rows` not filling viewport (Firefox bug 1346699).
* flex items aren't sorted according to "order", if they're separated by an abspos sibling (Firefox bug 1345873).
#### Other changes
* Enable mask longhands on SVG elements (Firefox bug 1319667).
* [css-grid] Fixed: `align-self`/`justify-self:stretch`/`normal` doesn't work on `<table>` grid items (Firefox bug 1316051).
* Fixed: `clip-path: circle()` with large reference box and percentage radius does not render correctly (Firefox bug 1324713.
* When applying a `text-transform` value of `uppercase` to Greek text, the accent on the disjunctive eta (ή) is no longer removed (see Firefox bug 1322989).
* The availability of the `contents` value of `display` was controlled through the `layout.css.display-contents.enabled` pref. In Firefox 53, this pref has been removed altogether, so the value will always be available and can no longer be disabled (Firefox bug 1295788).
### JavaScript
* ECMAScript 2015 semantics for the `Function.name` properties have been implemented. This includes inferred names on anonymous functions (`var foo = function() {}`) (Firefox bug 883377).
* ECMAScript 2015 semantics for closing iterators have been implemented. This affects the `for...of` loop, for example (Firefox bug 1147371).
* The Template Literal Revision proposal that lifts escape sequence restrictions on tagged template literals has been implemented (Firefox bug 1317375).
* The static `length` property of `TypedArray` objects was changed from 3 to 0 as per ES2016 (Firefox bug 1317306).
* `SharedArrayBuffer` can now be used in `DataView` objects (Firefox bug 1246597).
* In earlier versions of the specification, `SharedArrayBuffer` objects needed to be explicitly transferred during structured cloning. In the new specification, they aren't transferable objects anymore and thus must not be in the transfer list. The new behavior used to present a console warning only, but will now throw an error (Firefox bug 1302037).
* The `ArrayBuffer` length is now limited to `Number.MAX_SAFE_INTEGER` (>= 2 \*\* 53) (Firefox bug 1255128).
* `Error` and other native error object prototypes like `RangeError` etc. are now ordinary objects instead of proper Error objects. (In particular, `Object.prototype.toString.call(Error.prototype)` is now `"[object Object]"` instead of `"[object Error]"`.) (Firefox bug 1213341).
### Events
* CSS Transitions: The `transitionstart`, `transitionrun`, and `transitioncancel` events have been implemented (see Firefox bug 1264125 and Firefox bug 1287983).
* The `CompositionEvent` constructor has been implemented (see Firefox bug 1002256).
* The `MouseEvent.x` and `MouseEvent.y` aliases of `MouseEvent.clientX`/`MouseEvent.clientY` have been implemented (see Firefox bug 424390).
* The `auxclick` event and corresponding event handler have been implemented (see Firefox bug 1304044).
* The `transitioncancel` event is now fired after a transition is cancelled.
### DOM
* The `pathname` and `search` properties of links (like for `<a>` and `<link>` elements' interfaces previously returned the wrong parts of the URL. For example, for a URL of `http://z.com/x?a=true&b=false`, `pathname` would return "`/x?a=true&b=false"` and `search` would return "", rather than "`/x`" and "`?a=true&b=false"` respectively. This has now been fixed (Firefox bug 1310483).
* The `URLSearchParams()` constructor now accepts a string or sequence of strings as an init object (Firefox bug 1330678).
* The `Selection.setBaseAndExtent()` method of the Selection API is now implemented (see Firefox bug 1321623).
* The "fakepath" addition to `file` type `<input>` `values` has been implemented in Gecko, giving it parity with other browsers (see Firefox bug 1274596).
* `Node.getRootNode()` has been implemented, replacing the deprecated `Node.rootNode` property (Firefox bug 1269155).
* Own properties of `Plugin` and `PluginArray` objects are no longer enumerable (Firefox bug 1270366).
* Named properties of `MimeTypeArray` objects are no longer enumerable (Firefox bug 1270364).
* The Permissions API now has a new permission name available — `persistent-storage` — as used when making a `Permissions.query()` (see Firefox bug 1270038). This allows an origin to use a persistent box (i.e., persistent storage) for its storage, as per the Storage API.
* The `Performance.timeOrigin` property has been implemented (Firefox bug 1313420).
### Workers and service workers
* The Network Information API is now available in workers (see Firefox bug 1323172).
* Server-sent events can now be used in workers (see Firefox bug 1267903).
* `ExtendableEvent.waitUntil()` can now be called asynchronously (see Firefox bug 1263304).
### WebGL
* The `WEBGL_compressed_texture_astc` WebGL extension has been implemented (Firefox bug 1250077).
* The `WEBGL_debug_renderer_info` WebGL extension is now enabled by default (Firefox bug 1336645).
### Audio, video, and media
#### General
* Beginning in **Firefox 53 for Android**, decoding of media is handled out-of-process for improved performance on multi-core systems (Firefox bug 1333323).
#### Media elements
* The `HTMLMediaElement.play()` method, used to begin playback of media in any media element, now returns a `Promise` which is fulfilled when playback begins and is rejected if an error occurs (Firefox bug 1244768).
#### Web Audio API
* The `AudioScheduledSourceNode` interface has been added and the `AudioBufferSourceNode`, `ConstantSourceNode`, and `OscillatorNode` interfaces are now based on it (Firefox bug 1324568).
* All the different audio node types have had constructors added to them (Firefox bug 1322883).
#### WebRTC
* The `RTCPeerConnection` methods `createOffer()` and `createAnswer()` now return a `Promise` that returns an object conforming to the `RTCSessionDescriptionInit` dictionary instead of returning an `RTCSessionDescription` directly. Existing code will continue to work, but new code can be written more simply.
* Similarly, the `RTCPeerConnection` methods `setLocalDescription()` and `setRemoteDescription()` now accept as input an object conforming to the dictionary `RTCSessionDescriptionInit` dictionary. Existing code continues to work, but can be simplified.
* `RTCPeerConnection.addIceCandidate()` now accepts as input an initialization object. This is compatible with existing code but allows new code to be written slightly more simply when used in tandem with the changes listed above (Firefox bug 1263312).
* DTMF support is now enabled by default using `RTCDTMFSender`. See Using DTMF with WebRTC for more information on how this works.
### HTTP/Networking
* Gecko now has a pref available in `about:config` to allow users to set their default `Referrer-Policy` — `network.http.referer.userControlPolicy` (Firefox bug 1304623). Possible values are:
+ 0 — `no-referrer`
+ 1 — `same-origin`
+ 2 — `strict-origin-when-cross-origin`
+ 3 — `no-referrer-when-downgrade` (the default)
* Support for Next Protocol Negotiation (NPN) has been removed in favor of Application-Layer Protocol Negotiation (ALPN) — see Firefox bug 1248198.
* The `Large-Allocation` HTTP header is now available by default, and no longer hidden behind a pref (Firefox bug 1331083).
### SVG
* Partly implemented `SVGGeometryElement` interface (Firefox bug 1239100).
Removals from the web platform
------------------------------
### HTML/XML
* The `dom.details_element.enabled` pref — which controlled enabling/disabling `<details>` and `<summary>` element support in Firefox — has now been removed from `about:config`. These elements (first enabled by default in Firefox 49) can no longer be disabled. See Firefox bug 1271549.
* The `mozapp` attribute of the `<iframe>` element /`HTMLIFrameElement` interface has been removed — this was used to enable a Firefox OS app to be embedded in a mozilla-prefixed Browser API `<iframe>` (Firefox bug 1310845).
* The `HTMLIFrameElement.setInputMethodActive()` method and `InputMethod` interface (used to set and manage IMEs on Firefox OS apps) has been removed (Firefox bug 1313169).
### CSS
* Removed `-moz` prefixed variant of `:dir()` pseudo-class (Firefox bug 1270406).
* The `-moz` prefixed version of `text-align-last` got removed (Firefox bug 1276808).
* Removed `-moz` prefixed variant of `calc()` method (Firefox bug 1331296).
* The proprietary `-moz-samplesize` media fragment (added to aid in delivery of downsampled images to low memory Firefox OS devices; see Firefox bug 854795) has been removed (Firefox bug 1311246).
### JavaScript
* The non-standard `ArrayBuffer.slice()` method has been removed (but the standardized version `ArrayBuffer.prototype.slice()` is kept, see Firefox bug 1313112).
### APIs
* The Wi-Fi information API, Speaker Manager API, and Tethering API, and Settings API] have been removed from the platform (see Firefox bug 1313788, Firefox bug 1317853, Firefox bug 1313789, and Firefox bug 1313155 respectively).
### Other
* The `legacycaller` has been removed from the `HTMLEmbedElement` and `HTMLObjectElement` interfaces (Firefox bug 909656).
Changes for add-on and Mozilla developers
-----------------------------------------
### WebExtensions
New APIs:
* `browsingData`
* `identity`
* `contextualIdentities`
Enhanced APIs:
* `storage.sync`
* `page_action`, `browser_action`, `password`, `tab` context types in `contextMenus`
* `webRequest.onBeforeRequest` now supports `requestBody`
* `tabs.insertCSS` now supports `cssOrigin`, enabling you to insert user style sheets.
### JavaScript code modules
* The asynchronous [AddonManager APIs]((/en-US/docs/Mozilla/Add-ons/Add-on\_Manager/AddonManager) now support `Promises` as well as callbacks (Firefox bug 987512.
Older versions
--------------
* Firefox 52 for developers
* Firefox 51 for developers
* Firefox 50 for developers
* Firefox 49 for developers
* Firefox 48 for developers
* Firefox 47 for developers
* Firefox 46 for developers
* Firefox 45 for developers
* Firefox 44 for developers
* Firefox 43 for developers
* Firefox 42 for developers
* Firefox 41 for developers
* Firefox 40 for developers
* Firefox 39 for developers
* Firefox 38 for developers
* Firefox 37 for developers
* Firefox 36 for developers
* Firefox 35 for developers
* Firefox 34 for developers
* Firefox 33 for developers
* Firefox 32 for developers
* Firefox 31 for developers
* Firefox 30 for developers
* Firefox 29 for developers
* Firefox 28 for developers
* Firefox 27 for developers
* Firefox 26 for developers
* Firefox 25 for developers
* Firefox 24 for developers
* Firefox 23 for developers
* Firefox 22 for developers |
Firefox 8 for developers - Mozilla | Firefox 8 for developers
========================
Firefox 8 was released on November 8, 2011. This article provides information both for web developers and for add-on and Mozilla project developers to help take full advantage of the features of this release.
Changes for web developers
--------------------------
### HTML
* The `HTMLImageElement` `crossOrigin` property has been added and the `crossorigin` attribute has been added to the `<img>` element. (see Firefox bug 664299)
* The `HTMLSelectElement.add()` method now supports either an item or index of an item that the new item should be inserted before. Previously it only supported an item. (see Firefox bug 666200)
* The `HTMLIsIndexElement` constructor has been removed. No elements have implemented this interface since before Firefox 4.
* The HTML5 "context menu" feature (`contextmenu` attribute), which lets you add custom element specific items to native context menu, is now supported (the implementation is still experimental awaiting changes in the specification; see Firefox bug 617528).
* Support for the `HTMLElement.accessKeyLabel` attribute has been added to all elements.
* The `<input>` and `<textarea>` elements now support the `selectionDirection` attribute, and their `setSelectionRange()` methods have been updated to support optionally specifying a direction.
* Most elements now get a focus ring drawn around them if they've been made focusable by using the `tabindex` attribute and the user then focuses the element.
* In a set of nested `<label>` elements click events do no longer trigger multiple <label> elements, which caused Firefox to stop responding in the past (see Firefox bug 646157).
### DOM
* The `insertAdjacentHTML` method has been implemented.
* `BlobBuilder` now has a `getFile()` method that returns the content of the blob as a file.
* The `FileReaderSync` interface (part of the FileAPI) has been implemented.
* Event handling in nested `<label>`s has been fixed.
* You can now use `window.postMessage()` to pass `File` and `FileList` objects between windows.
* When editing `contenteditable` areas, exiting a heading by pressing return, or exiting list editing mode by pressing return twice, now returns to paragraph entry mode (that is, paragraphs inside `<p>` blocks) instead of separating lines by `<br>` elements.
* Fixed a bug that prevents justification from taking effect properly when applied to the first line in a `contenteditable` area.
* Fixed a bug that caused pressing delete or backspace at the beginning of a `contenteditable` area to affect the previous `contenteditable` block if one is present.
* `Document.getSelection()` now returns the same `Selection` object as `window.getSelection()`, instead of *stringifying* it.
* The HTML5 `selectionDirection` property makes it possible to define the direction of the selection in an editable text.
* `HTMLMediaElement` now have a `seekable` property that return a `TimeRanges` object.
* The `HTMLMediaElement``.preload` attribute now correctly reflects as an *enumerated value*.
* `crossOrigin` property defaults to "Anonymous" when an invalid value is used.
* `navigator.cookieEnabled` now returns correct information when the default cookie setting is overridden on a per-site basis.
### JavaScript
* `RegExp.exec()` and `RegExp.test()` called with no arguments now match against the string "undefined".
* `String.search()` and `String.match()` called with no arguments or `undefined` now match against the empty string and thus match every string.
* Support for watchlists has been implemented with the new (non-standard) `watch()` and `unwatch()` methods.
### CSS
* `<resolution>` now accepts `<number>`, not just `<integer>` values as per the specification.
* Hyphenation rules have been added for many new languages when using `hyphens`.
* Handling of `background-size` has been revised to more closely match the specification.
* In the past, `text-decoration` in quirks mode had line thickness and position adjusted on descendant text to match the descendant. Now standards mode and quirks mode rendering are more similar.
* Horizontal positioning for elements has been brought more in line with the specification in many cases. Documentation for this is forthcoming, but for now, see Firefox bug 682780, comment 23 for details.
* SVG images are now scaled properly when used as background images.
### Network
* Double quotes are no longer accepted as a delimiter for RFC 2231 or RFC 5987 encoding, as per those RFCs.
* MIME header field parser (`Content-Disposition`) now requires "=" in parameters.
* Scripts are no longer downloaded when JavaScript is disabled.
* SSL 2.0 is no longer supported.
### WebSockets
* The `WebSocket` object's `send()` method no longer incorrectly returns a Boolean value.
* The `WebSocket` object's `close()` method now matches the current draft of the standard, and close events now properly use the `CloseEvent` interface.
* The `WebSocket` object's `extensions` attribute is now supported.
* The WebSocket constructor now supports an array of protocols as well as a single protocol string.
* Mixed content is not allowed with WebSockets; that is, you can no longer open a connection to a non-secure WebSocket server from secure content.
* Connection errors with WebSockets now trigger the `onerror` handler.
* WebSocket API has been updated to the latest draft of the specification (see Firefox bug 674890, Firefox bug 674527, and Firefox bug 674716).
* The deflate-stream extension to WebSockets has been disabled; it has been deprecated, and was breaking compatibility with some sites.
### WebGL
* Cross-domain textures can now be allowed with CORS approval.
* Cross-process rendering with Direct2D/Direct3D 10.
### MathML
* Support for the `displaystyle` attribute on the top-level `<math>` element has been added.
* The interpretation of negative row numbers for the `align` attribute on `<mtable>` has been corrected.
### Developer tools
* The `console` object has a new `dir()` method, which displays an interactive list of the properties on a specified object.
Changes for Mozilla and add-on developers
-----------------------------------------
See Updating add-ons for Firefox 8 for a guide to changes you're likely to have to make your add-ons compatible with Firefox 8.
**Note:** Firefox 8 requires that binary components be recompiled, as do all major releases of Firefox.
### XPCOM
`Components.utils`
The new methods `Components.utils.createObjectIn()` and `Components.utils.makeObjectPropsNormal()` have been created to make it easier to create objects in specific compartments.
#### Other XPCOM-related changes
* You can now instantiate DOM `File` objects from component code by doing new File, instead of having to instantiate an `nsIDOMFile` directly.
* The `nsTPtrArray` array type has been removed. Its functionality is now all available on `nsTArray`, which now offers the `SafeElementAt()` method when instantiated using a pointer type.
### Workers
It is no longer possible to access XPCOM objects from ChromeWorkers. XPConnect has been disabled in worker contexts as of Firefox bug 649537.
### XUL
* A bug in `document.execCommand()` that occurred when calling it on the value of `contentDocument` has been fixed. Since Firefox 3, this has resulted in errors instead of working correctly.
* Bootstrapped add-ons can now load chrome using a `chrome.manifest` file.
* XUL images now shrink down with the same ratio in both directions when specifying maximum sizes.
### Changes to the build system
* The following build configuration options have been removed:
+ `--enable-timeline`
+ `--disable-storage`
+ `--necko-disk-cache`
* When compiling IDL files to headers, the header file `jspubtd.h` is automatically included when needed. Manual inclusions of `jspubtd.h` and/or `jsapi.h` in IDL files that use jsval or [implicit\_jscontext] are no longer necessary.
### Chrome registration
* The `platformversion` flag can be used in the chrome.manifest to specify Gecko version compatibility.
### Interface changes
* The `mozIJSSubScriptLoader.loadSubScript()` method now loads scripts from the startup cache when possible.
* The `ownerWindow` attribute has been removed from the `nsIAccessNode` interface.
* The `nsIDOMStorageWindow` interface has been merged into the `nsIDOMWindow` interface.
* All members of the `nsIDOMWindowInternal` interface have been moved into the `nsIDOMWindow` interface. The interface itself (with no members) remains available for compatibility until Firefox 9.
* In order to improve performance, callback handling for asynchronous Places database updates has been changed. See the new `mozIVisitInfoCallback.handleResult()` and `mozIVisitInfoCallback.handleError()` methods, which replace the old single method for both error and success condition handling.
* The `KIND_MAPPED` attribute of `nsIMemoryReporter` has been deprecated in favor of `KIND_NONHEAP`, new unit types `UNITS_COUNT_CUMULATIVE` and `UNITS_PERCENTAGE` have been added.
* The `nsIMemoryReporterManager` interface has a new `explicit` attribute, which reports the total size of explicit memory allocations.
* The `nsIMemoryReporterManager` interface has a new `resident` attribute, which reports the amount of physical memory used.
* The `nsINetworkLinkService` interface has a new attribute, `linkType`. This attribute provides the type of network connection in use. All Operating Systems currently return `LINK_TYPE_UNKNOWN`. Android support was backed out due to perceived security concerns.
* The `nsISelection2` interface has been merged into the `nsISelectionPrivate` interface.
* The `nsISelection3` interface has been merged into the `nsISelection` interface.
* The `nsISessionStartup` attribute state is now a `jsval` instead of a string, for performance reasons.
* The `nsIDocShell` attribute `isActive` is now `false` for minimized windows.
* The `nsIDownloadHistory.addDownload()` method now saves the target where the download is saved on the local file system.
#### Removed interfaces
The following interfaces were implementation details that are no longer needed:
* `nsITimelineService`
* `nsIDOMHTMLIsIndexElement`
The `nsIWorkerFactory` interface has been removed as well. Workers can still be created using the `Worker` and `ChromeWorker` constructors.
### Other changes
* When a window is minimized, un-minimized, or switches between full screen and windowed mode, it receives a `sizemodechange` event.
* You can now use the `extensions.autoDisableScopes` preference to disable automatic installation of add-ons from specific add-on install locations.
* The new `mozSyntheticDocument` property on `Document` objects lets you determine whether a document is synthetic (that is, something like a standalone image, video, or audio file) rather than a full, standard DOM document. This can be useful, for example, if you want to present different user interface in this situation (such as adding contextual items differently depending on this case).
* You can now specify a filter when opening `about:config`; for example, "about:config?filter=sessionstore" will show only session storage related preferences.
See also
--------
* Firefox 7 for developers
* Firefox 6 for developers
* Firefox 5 for developers
* Firefox 4 for developers
* Firefox 3.6 for developers
* Firefox 3.5 for developers
* Firefox 3 for developers
* Firefox 2 for developers
* Firefox 1.5 for developers |
Firefox 119 for developers - Mozilla | Firefox 119 for developers
==========================
This article provides information about the changes in Firefox 119 that affect developers. Firefox 119 was released on October 24, 2023.
Changes for web developers
--------------------------
### HTML
#### Removals
* The `<input>` element no longer supports the non-standard `mozactionhint` attribute. Use `enterkeyhint` instead. (See Firefox bug 1735980 for more details.)
### CSS
* The `attr()` CSS function fallback value is now supported. This allows the setting of a fallback value to be used if the global attribute is missing (Firefox bug 1448248).
### JavaScript
* The `Object.groupBy()` and `Map.groupBy()` static methods for grouping the elements of an iterable are now supported (See Firefox bug 1792650 for more details.)
* The `String.prototype.isWellFormed()` and `String.prototype.toWellFormed()` methods respectively can be used to check if a string contains well-formed Unicode text (i.e. contains no lone surrogates) and sanitize an ill-formed string to well-formed Unicode text.
(See Firefox bug 1850755 for more details).
### SVG
* The SVG attributes that accept a `<length>` value now support level 3 `<length>` CSS data types for all SVG elements. This enables the sizing of SVG elements based on font sizes (`cap`, `rem`, etc.), viewport (`vh`, `vw`, `vmin`, etc.), or absolute lengths (`px`, `cm`, etc.), e.g. `<line x1="10vw" y1="10vh" x2="50vw" y2="50vh"/>`. (See Firefox bug 1287054 for more details).
### HTTP
* The `credentialless` directive of the `Cross-Origin-Embedder-Policy` HTTP response header is now supported on desktop platforms (and mobile platforms other than Android), allowing `no-cors` requests for resources to be made on cross-origin servers that have not explicitly opted into it, albeit without cookies or other credentials (Firefox bug 1851467).
### APIs
* The relative priority for send streams can now be specified by including the `sendOrder` property inside an options argument passed to `WebTransport.createBidirectionalStream()` and `WebTransport.createUnidirectionalStream()` (Firefox bug 1816925).
* The `getAuthenticatorData()`, `getPublicKeyAlgorithm()`, and `getPublicKey()` methods of the `AuthenticatorAttestationResponse` interface are now supported (see Firefox bug 1816519 and Firefox bug 1816520).
* The Credential Properties Extension (`credProps`) of the Web Authentication API is supported, allowing users to query if credentials are discoverable after creation/registration (Firefox bug 1844437).
* The `SubtleCrypto.deriveKey()` method now supports the HKDF algorithm as an option for its `derivedKeyAlgorithm` parameter (see Firefox bug 1851928).
* The `parseCreationOptionsFromJSON()`, `parseRequestOptionsFromJSON()`, and `toJSON()` methods of the `PublicKeyCredential` interface are now supported.
These are convenience methods for converting objects used for creating and sharing credentials objects to JSON representations that can be serialized/deserialized and shared with a server (see Firefox bug 1823782).
#### DOM
* ARIA reflection is now supported by default for attributes that do not reference other elements; only non-IDREF attributes are reflected. You can now get and set ARIA attributes on DOM elements directly via JavaScript APIs, rather than by using `setAttribute` and `getAttribute`. For example, `buttonElement.ariaPressed = "true";` is now supported in addition to `buttonElement.setAttribute("aria-pressed", "true");` (Firefox bug 1785412).
### WebDriver conformance (WebDriver BiDi, Marionette)
#### General
* When performing a `pointerDown` action with the middle or right mouse button pressed, the `mousedown` event as emitted by the related HTML element had the value of the `buttons` property swapped (Firefox bug 1850086).
* When performing a `scroll` action of input type `wheel` with an origin set to `pointer` an `invalid argument` error was inappropriately raised, whereas per the current WebDriver specification this combination is not supported (Firefox bug 1850166).
#### WebDriver BiDi
* Added the `browsingContext.reload` command that allows users to reload the page or a frame that is currently displayed within a given browsing context (Firefox bug 1830859).
* Added the `browsingContext.userPromptClosed` event that is emitted when a user prompt of type `alert`, `confirm`, or `prompt` got closed (Firefox bug 1824221).
* Added the `browsingContext.navigationStarted` event that is emitted when a new navigation is started by Firefox (Firefox bug 1756595).
* Added the `script.realmCreated` and `script.realmDestroyed` events that allow users to monitor the lifetime of JavaScript Realms of a given browsing context. Such a Realm is basically an isolated execution environment (`sandbox`) with its own unique global object (window) (Firefox bug 1788657, Firefox bug 1788659).
* The `browsingContext.userPromptOpened` event was accidentally sent when a HTTP Authentication dialog was opened (Firefox bug 1853302).
* Unwanted events with the `context` field set to `null` will no longer be emitted. Because the underlying browsing context has been closed such events are no longer valid (Firefox bug 1847563).
#### Marionette
* The list of possible error codes when trying to install a WebExtension by using the `Addon:Install` command has been updated to match the latest error codes of Firefox (Firefox bug 1852537).
Older versions
--------------
* Firefox 118 for developers
* Firefox 117 for developers
* Firefox 116 for developers
* Firefox 115 for developers
* Firefox 114 for developers
* Firefox 113 for developers
* Firefox 112 for developers
* Firefox 111 for developers
* Firefox 110 for developers
* Firefox 109 for developers
* Firefox 108 for developers
* Firefox 107 for developers
* Firefox 106 for developers
* Firefox 105 for developers
* Firefox 104 for developers
* Firefox 103 for developers
* Firefox 102 for developers
* Firefox 101 for developers
* Firefox 100 for developers
* Firefox 99 for developers
* Firefox 98 for developers
* Firefox 97 for developers
* Firefox 96 for developers
* Firefox 95 for developers
* Firefox 94 for developers
* Firefox 93 for developers
* Firefox 92 for developers
* Firefox 91 for developers
* Firefox 90 for developers
* Firefox 89 for developers
* Firefox 88 for developers |
Firefox 62 for developers - Mozilla | Firefox 62 for developers
=========================
This article provides information about the changes in Firefox 62 that will affect developers. Firefox 62 was released on September 5, 2018.
Changes for web developers
--------------------------
### Developer tools
* The Shape Path Editor is now available by default — see Edit Shape Paths in CSS for more information.
* You can now split the Rules view out into its own pane, separate from the other tabs on the CSS pane. See Page inspector 3-pane mode for more details.
* The Grid inspector has updated features, and all new documentation — see CSS Grid Inspector: Examine grid layouts.
* You now have four options for the location of the Developer Tools. In addition to the default location on the bottom of the window, you can choose to locate the tools on either the left or right sides of the main window or in a separate window (Firefox bug 1192642).
* A close button has been added to the split console toolbar.
* If the option to "Select an iframe as the currently targeted document" is checked, the icon will appear in the toolbar while the Settings tab is displayed, even if the current page doesn't include any iframes (Firefox bug 1456069).
* The Network Monitor's Cookies tab now shows the cookie `samesite` attribute (Firefox bug 1452715).
* Responsive design mode now works inside container tabs (Firefox bug 1306975).
* When CORS errors occur and are reported on the console, Firefox now provides a link to the corresponding page in our CORS error documentation (Firefox bug 1475391).
* Create a screenshot of the current page (with an optional filename) from the Console tab (Firefox bug 1464461) using the following command:
```bash
:screenshot <filename.png> --fullpage
```
where `<filename.png>` is the desired filename. The file will be saved to your downloads folder. The `--fullpage` parameter is optional, but if included, it will save the full web page. This option also adds `-fullpage` to the name of the file. For a list of all options available for this command, enter: `:screenshot --help`
#### Removals
* The *Developer Toolbar/GCLI* (accessed with `Shift` + `F2`), **has been removed** from Firefox (Firefox bug 1461970). Both the Developer Toolbar UI and the GCLI upstream library have become unmaintained, some of its features are broken (some ever since e10s), it is blocking the `unsafeSetInnerHTML` work, usage numbers are very low, alternatives exist for the most used commands.
### HTML
*No changes.*
### CSS
* `:-moz-selection` has been unprefixed to `::selection` (Firefox bug 509958).
* `x` is now supported as a unit for the `<resolution>` type (Firefox bug 1460655).
* `shape-margin`, `shape-outside`, and `shape-image-threshold` are now enabled by default (Firefox bug 1457297).
#### Removals
* All XUL `display` values with the exception of `-moz-box` and `-moz-inline-box` have been removed from non-XUL documents in Firefox bug 1288572.
### SVG
*No changes.*
### JavaScript
* The `WebAssembly.Global()` constructor is now supported, along with global variables in WebAssembly (Firefox bug 1464656).
* The `Array.prototype.flat()` and `Array.prototype.flatMap()` methods are now enabled by default (Firefox bug 1435813).
* The `import.meta` property has been implemented to expose context-specific metadata to a JavaScript module (Firefox bug 1427610).
* JavaScript string literals may now directly contain the U+2028 LINE SEPARATOR and U+2029 PARAGRAPH SEPARATOR characters. As a consequence, `JSON` syntax is now a subset of JavaScript literal syntax (see Firefox bug 1435828 and the TC39 proposal json-superset).
* For out-of-bounds typed array indexes, `Reflect.defineProperty()` and `Reflect.set()` will now return `false` instead of `true` (Firefox bug 1308735).
#### Removals
* The `DOMPoint` and `DOMPointReadOnly` constructors no longer support an input parameter of type `DOMPointInit`; the values of the properties must be specified using the `x`, `y`, `z`, and `w` parameters (Firefox bug 1186265).
* The `URL.createObjectURL()` method no longer supports creating object URLs to represent a `MediaStream`. This capability has been obsolete for some time, since you can now set `HTMLMediaElement.srcObject` to the `MediaStream` directly (Firefox bug 1454889).
### APIs
#### New APIs
* The Speech Synthesis API (Text-to-Speech) is now enabled by default on Firefox for Android (Firefox bug 1463496).
#### DOM
* The `DOMPointReadOnly` interface now supports the static function `DOMPointReadOnly.fromPoint()`, which creates a new point object from a dictionary that's compatible with `DOMPointInit`, which includes any `DOMPoint` object. This function is also available on `DOMPoint` (Firefox bug 1186265).
* For compatibility purposes, the `Event.srcElement` property is now supported. It is an alias for `Event.target` (Firefox bug 453968).
* `Navigator.registerProtocolHandler()` now must only be called from a secure context (Firefox bug 1460506).
* The `Navigator.registerContentHandler()` method has been disabled by default in preparation for being removed entirely, as it's been obsolete for some time (Firefox bug 1460481).
* The `DataTransfer()` constructor has been implemented (Firefox bug 1351193).
* `Document.domain` can no longer return `null` (Firefox bug 819475). If the domain cannot be identified, then `domain` returns an empty string instead of `null`.
* Added the `console.timeLog()` method to display the current value of a console timer while continuing to track the time (Firefox bug 1458466).
* Added `console.countReset()` to reset a console counter value (Firefox bug 1459279).
#### DOM events
*No changes.*
#### Service workers
*No changes.*
#### Media, Web Audio, and WebRTC
* The `"media.autoplay.enabled"` preference now controls automatic playback of both audio and video media, instead of just video media (Firefox bug 1413098).
* The `ChannelSplitterNode` has been fixed to correctly default to having 6 channels with the `channelInterpretation` set to `"discrete"` and the `channelCountMode` set to `"explicit"`, as per the specification (Firefox bug 1456265).
#### Removals
* The `userproximity` and `deviceproximity` events, as well as the `UserProximityEvent` and `DeviceProximityEvent` interfaces, have been disabled by default behind the `device.sensors.proximity.enabled` preference (Firefox bug 1462308).
* The `devicelight` event of type `DeviceLightEvent` has been disabled by default behind the `device.sensors.ambientLight.enabled` preference (Firefox bug 1462308).
* The `DOMSubtreeModified` and `DOMAttrModified` mutation events are no longer thrown when the `style` attribute is changed via the CSSOM (Firefox bug 1460295.
* Support for `CSSStyleDeclaration.getPropertyCSSValue()` has been removed (Firefox bug 1408301).
* Support for `CSSValue`, `CSSPrimitiveValue`, and `CSSValueList` has been removed (Firefox bug 1459871).
* `window.getComputedStyle()` no longer returns `null` when called on a `Window` which has no presentation (Firefox bug 1467722).
### HTTP
#### Removals
* The deprecated CSP `referrer` directive has been removed. Please use the `Referrer-Policy` header instead (Firefox bug 1302449).
### Security
*No changes.*
### Plugins
*No changes.*
### WebDriver conformance (Marionette)
#### New features
* Command `WebDriver:ElementSendKeys` has been made WebDriver conforming for file uploads (Firefox bug 1448792).
* User prompts as raised by `beforeunload` events are automatically dismissed for `WebDriver:Get`, `WebDriver:Back`, `WebDriver:Forward`, `WebDriver:Refresh`, and `WebDriver:Close` commands (Firefox bug 1434872).
* `WebDriver:PerformActions` for `Ctrl` + `Click` synthesizes a `contextmenu` event (Firefox bug 1421323).
#### API changes
* Removed obsolete endpoints including `getWindowPosition`, `setWindowPosition`, `getWindowSize`, and `setWindowSize` (Firefox bug 1348145).
* WebDriver commands which return success with data `null` now return an empty dictionary (Firefox bug 1461463).
#### Bug fixes
* `WebDriver:ExecuteScript` caused cyclic reference error for WebElement collections (Firefox bug 1447977).
* Dispatching a `pointerMove` or `pause` action primitive could cause a hang, and the command to never send a reply (Firefox bug 1467743, Firefox bug 1447449).
### Other
*No changes.*
Changes for add-on developers
-----------------------------
### API changes
* Added the `webRequest.getSecurityInfo()` API to examine details of TLS connections (Firefox bug 1322748).
* Added the `browserSettings.newTabPosition` to customize where new tabs open (Firefox bug 1344749).
* `windowTypes` has been deprecated in `windows.get()`, `windows.getCurrent()`, and `windows.getLastFocused()` (Firefox bug 1419132).
* It's now possible to modify a browser action on a per-window basis (Firefox bug 1419893).
### Manifest changes
* New `open_at_install` property of the `sidebar_action` manifest key enables extensions to control whether their sidebars should open automatically on install or not (Firefox bug 1460910).
* Changes to the `browser_style` property of various manifest keys:
+ In `page_action` and `browser_action` it defaults to `false`.
+ In `sidebar_action` and `options_ui` it defaults to `true`.
### Theme changes
* New `tab_background_separator` property of the `theme` manifest key enables extensions to change the color of the tab separator (Firefox bug 1459455).
### Removals
* Support for unpacked sideloaded extensions has been removed (Firefox bug 1385057).
* The warning about `browser_style` displayed when temporarily loading an extension for testing is no longer displayed (Firefox bug 1404724).
Older versions
--------------
* Firefox 61 for developers
* Firefox 60 for developers
* Firefox 59 for developers
* Firefox 58 for developers
* Firefox 57 for developers
* Firefox 56 for developers
* Firefox 55 for developers
* Firefox 54 for developers
* Firefox 53 for developers
* Firefox 52 for developers
* Firefox 51 for developers
* Firefox 50 for developers
* Firefox 49 for developers
* Firefox 48 for developers
* Firefox 47 for developers
* Firefox 46 for developers
* Firefox 45 for developers
* Firefox 44 for developers
* Firefox 43 for developers
* Firefox 42 for developers
* Firefox 41 for developers
* Firefox 40 for developers
* Firefox 39 for developers
* Firefox 38 for developers
* Firefox 37 for developers
* Firefox 36 for developers
* Firefox 35 for developers
* Firefox 34 for developers
* Firefox 33 for developers
* Firefox 32 for developers
* Firefox 31 for developers |
Firefox 29 for developers - Mozilla | Firefox 29 for developers
=========================
Firefox 29 was released on April 29, 2014. This article lists key changes that are useful not only for web developers, but also Firefox and Gecko developers as well as add-on developers.
Changes for Web developers
--------------------------
### Developer Tools
Major changes include:
* Vastly improved web console - Arrays are shown inline without clicking to bring up in the right inspector, window objects show their URL, etc.
* Added the console API to Web Workers (bug 620935). Now you can log messages to the Web Console from Web Workers.
* The Network Monitor tool now shows performance statistics using pie charts (Firefox bug 846601).
* On the Inspector, preview tooltips of CSS transforms are now available (Firefox bug 726427).
* DOM elements seen in the debugger and console can be removed or inspected directly, via the new buttons to the right of the variable listing.
* A CSS source map is now supported by the Style Editor (Firefox bug 926014).
* Autocompletion of CSS properties and values has been added to the Style Editor (Firefox bug 717369).
*See the Mozilla Hacks blog post for details and other smaller changes.*
### CSS
* CSS variables have been implemented (Firefox bug 773296). Mozilla Hacks article can be found here. They are enabled by default only for non-release builds (on release builds flip the pref `layout.css.variables.enabled` to `true` if you want to play with them).
* Flexboxes now support `visibility``: collapse` (Firefox bug 783470).
* The `box-sizing` property has been unprefixed (Firefox bug 243412).
* The `will-change` property, a hint to that something will animate has been added. The preference `layout.css.will-change.enabled` must be switched to `true` to enable it. (Firefox bug 940842)
* Scientific exponential notation, like `3e1` or `10e+0`, is now supported for `<number>` values and derivatives, like `<percentage>` and unit values, but not `<integer>` (Firefox bug 964529).
* Images of type `<gradient>` are now supported in `border-image` (Firefox bug 709587).
* The `touch-action` property has been implemented. It is not activated by default; the `layout.css.touch_action.enabled` pref controls it. (Firefox bug 795567)
* Remove redundant default style for <pre> element from quirk.css (Firefox bug 948914).
* CSS Variables fallback incorrectly implemented (primary cycles) (Firefox bug 950497).
* @supports conditions with tokens after a declaration's priority should evaluate to false (Firefox bug 909170).
### HTML
* `<input type=color>` and `<input type=number>` are available by default.
* Support for the non standard `<pre cols>` has been removed, as well as the layout effect of `<pre wrap>`. Both effects can, and should, be achieved using CSS. (Firefox bug 949879)
### JavaScript
* New ECMAScript 2015 String methods: `String.prototype.codePointAt()` and `String.prototype.fromCodePoint()` have been implemented (Firefox bug 918879).
* The ECMAScript Internationalization API (ECMA-402) has been implemented and is now enabled by default in Firefox Desktop (Firefox bug 853301):
+ New objects in the new `Intl` object namespace:
- `Intl.Collator`
- `Intl.DateTimeFormat`
- `Intl.NumberFormat`
+ The following methods of `String`, `Number` and `Date` have been updated to include the `locales` and `options` arguments per ECMA-402:
- `String.prototype.localeCompare()`
- `Number.prototype.toLocaleString()`
- `Date.prototype.toLocaleString()`
- `Date.prototype.toLocaleDateString()`
- `Date.prototype.toLocaleTimeString()`
* To match the updated ECMAScript 2015 draft specification, the `Map` and `Set` objects now treat `-0` and `+0` as the same when checking for key and value equality.
* `Promise` has been enabled by default (Firefox bug 918806).
* Completed generators now return an `IteratorResult` object instead of throwing (Firefox bug 958951).
* A malformed JSON string parsed by `JSON.parse()` now yields a more detailed error message containing the line and column number that caused the parsing error. This is useful when debugging large JSON data.
* The `ArrayBuffer.isView()` method has been added (Firefox bug 896105).
### Interfaces/APIs/DOM
* A new type of workers, `SharedWorker`, is now available by default (Firefox bug 924089).
* The `URL` interface now supports the `searchParams` property returning a `URLSearchParams` object, allowing to modify the search params of a URL (Firefox bug 887836). The `URLSearchParams()` constructor allows easier parsing of query strings.
* The `navigator.onLine` property is now supported on `WorkerNavigator`, allowing to know the online/offline status in workers (Firefox bug 925437).
* As part of the implementation of Web Components, the `HTMLShadowElement` interface has been implemented behind the `dom.webcomponents.enabled`. Flip it to `true` if you want to use it. (Firefox bug 887538)
* The read-only property `HTMLIFrameElement.sandbox` is no longer a string but a `DOMTokenList` (Firefox bug 845057).
* On `HTMLCanvasElement.getContext()`, the value `moz-webgl` is no longer supported. Use the standard `webgl` value (Firefox bug 913597).
* The constructor for `ImageData` has been added. This interface can be used in a `Worker`. (Firefox bug 959958)
* The property `location.origin` is now available in workers (via `WorkerLocation`) (Firefox bug 964148).
* The `ValidityState.badInput` property has been implemented (Firefox bug 827161).
* The deprecated `Window.pkcs11` property has been removed; it was returning `null` since Firefox 3.0.14. (Firefox bug 964964)
* The `Node.cloneNode()` and `Document.importNode()` methods take the Boolean `deep` argument. Until now, if omitted, these methods acted as if the value of `deep` was `true`. But this behavior has been changed as per the latest spec, and if omitted, the methods will act as if the value was `false`. (Firefox bug 937461)
* `Window._content` is no longer available to Web content (Firefox bug 946564).
* `URLUtils.port` behavior has been slightly changed: set to `''` will set it to the default port associated with the protocol, and `0` to `0.` (Firefox bug 930450)
* `Document.referrer` is now based on the incumbent script (Firefox bug 887928).
* The Gamepad API is enabled by default (Firefox bug 878828).
* The `CanvasRenderingContext2D.drawSystemFocusRing()` method got renamed to `CanvasRenderingContext2D.drawFocusIfNeeded()` (Firefox bug 959820).
### MathML
*No change.*
### SVG
*No change.*
Security
--------
* The CSP 1.1 experimental `hash-source` directive has been implemented. The preference `security.csp.experimentalEnabled` should be set to `true` to enable this functionality (Firefox bug 883975).
Changes for add-on and Mozilla developers
-----------------------------------------
* Major Firefox theme changes affect most extensions that interact with the Firefox user interface.
* `nsISecurityCheckedComponent` has been removed (Firefox bug 794943). Most consumers can remove `nsISecurityCheckedComponent` from their interface definition and they will continue to work.
### Older versions
* Firefox 28 for developers
* Firefox 27 for developers
* Firefox 26 for developers
* Firefox 25 for developers
* Firefox 24 for developers
* Firefox 23 for developers
* Firefox 22 for developers
* Firefox 21 for developers
* Firefox 20 for developers
* Firefox 19 for developers
* Firefox 18 for developers
* Firefox 17 for developers
* Firefox 16 for developers
* Firefox 15 for developers
* Firefox 14 for developers
* Firefox 13 for developers
* Firefox 12 for developers
* Firefox 11 for developers
* Firefox 10 for developers
* Firefox 9 for developers
* Firefox 8 for developers
* Firefox 7 for developers
* Firefox 6 for developers
* Firefox 5 for developers
* Firefox 4 for developers
* Firefox 3.6 for developers
* Firefox 3.5 for developers
* Firefox 3 for developers
* Firefox 2 for developers
* Firefox 1.5 for developers |
Firefox 87 for developers - Mozilla | Firefox 87 for developers
=========================
This article provides information about the changes in Firefox 87 that will affect developers. Firefox 87 was released on March 23, 2021.
**Note:** See also In March, we see Firefox 87 on Mozilla Hacks.
Changes for web developers
--------------------------
### Developer Tools
* Developers can now use the Page Inspector to simulate `prefers-color-scheme` media queries, without having to change the operating system to light or dark mode (Firefox bug 1679408 and Firefox bug 1692272).
* Developers can now use the Page Inspector to toggle the `:target` pseudo-class for the currently selected element in addition to the pseudo-classes that were previously supported: `:hover`, `:active` and `:focus`, `:focus-within`, `:focus-visible`, and `:visited` (Firefox bug 1689899).
* Firefox 87 sees a number of Page Inspector improvements and bug fixes related to inactive CSS rules:
+ The `table-layout` property is now marked as inactive for non-table elements (Firefox bug 1551571).
+ The `scroll-padding` properties (shorthand and longhand) are now marked as inactive for non-scrollable elements (Firefox bug 1551577).
+ The `text-overflow` property was previously incorrectly marked as inactive for some `overflow` values (Firefox bug 1671457).
### HTML
*No changes.*
### CSS
* Some languages have digraphs that are always capitalized together, for example `IJ` in Dutch. The `::first-letter` pseudo-element now respects these digraphs and treats them as a single unit (Firefox bug 92176).
* The `<link>` element is no longer matched by `:link`, `:visited`, or `:any-link`. This aligns the behavior in Firefox to existing behavior in Chrome and to a recent spec change (Firefox bug 1687538).
#### Removals
* The following Firefox-specific theme-related media features have been disabled for use in web pages (Firefox bug 787521):
+ `-moz-mac-graphite-theme`
+ `-moz-mac-lion-theme`
+ `-moz-maemo-classic`
+ `-moz-windows-classic`
+ `-moz-windows-compositor`
+ `-moz-windows-default-theme`
+ `-moz-windows-theme`
+ `-moz-scrollbar-end-backward`
+ `-moz-scrollbar-end-forward`
+ `-moz-scrollbar-start-backward`
+ `-moz-scrollbar-start-forward`
+ `-moz-scrollbar-thumb-proportional`
+ `-moz-menubar-drag`
* The non-standard values of `caption-side` (`left`, `right`, `top-outside`, and `bottom-outside`) have been removed and placed behind the `layout.css.caption-side-non-standard.enabled` flag (Firefox bug 1688695).
### JavaScript
*No changes.*
### HTTP
* Some enterprise authentication services require that TLS client certificates be sent in CORS preflight requests. Users of these services can enable this (non-specification compliant) behavior using the `network.cors_preflight.allow_client_cert` preference (Firefox bug 1511151).
* The default `Referrer-Policy` has been changed to `strict-origin-when-cross-origin` (from `no-referrer-when-downgrade`), reducing the risk of leaking referrer information in cross-origin requests (Firefox bug 1589074).
* `Content-Length` has been added to the list of CORS-safelisted response headers (Firefox bug 1460299).
### Security
*No changes.*
### APIs
#### DOM
* The `beforeinput` event and `getTargetRanges()` method are now enabled by default. They allow web apps to override text edit behavior before the browser modifies the DOM tree, and provide more control over input events to improve performance. The global `beforeinput` event is sent to an `<input>` element — or any element whose `contenteditable` attribute is set to `true` — immediately before the element's value changes. The `getTargetRanges()` method of the `InputEvent` interface returns an array of static ranges that will be affected by a change to the DOM if the input event is not canceled.
### WebDriver conformance (Marionette)
* The work of rewriting Marionette to support Fission (site-isolation) has been finished, so the old Marionette implementation has been removed. The `marionette.actors.enabled` preference, which toggled between the new and old implementations, has therefore also been removed (Firefox bug 1669172).
* WebDriver commands following a call to `WebDriver:SwitchToFrame` will no longer fail with a "no such window" error if the frame's content hasn't yet finished loading (Firefox bug 1691348).
* After a cross-group page navigation, accessing a previously-retrieved element will now always raise a "stale element" error; there is no longer a chance that this action will lead to a "no such element" error (Firefox bug 1690308).
* `Addon:Uninstall` now raises an `unknown error` when the id of the add-on to uninstall is unknown (Firefox bug 1693022).
Changes for add-on developers
-----------------------------
* nativeMessaging is now an optional permission (Firefox bug 1630415).
* Added support for querying and setting color management related features with `browserSettings.colorManagement` (Firefox bug 1719688) and (Firefox bug 1714428).
Older versions
--------------
* Firefox 86 for developers
* Firefox 85 for developers
* Firefox 84 for developers
* Firefox 83 for developers
* Firefox 82 for developers
* Firefox 81 for developers
* Firefox 80 for developers
* Firefox 79 for developers
* Firefox 78 for developers
* Firefox 77 for developers
* Firefox 76 for developers
* Firefox 75 for developers
* Firefox 74 for developers
* Firefox 73 for developers
* Firefox 72 for developers
* Firefox 71 for developers
* Firefox 70 for developers
* Firefox 69 for developers
* Firefox 68 for developers
* Firefox 67 for developers
* Firefox 66 for developers
* Firefox 65 for developers
* Firefox 64 for developers
* Firefox 63 for developers
* Firefox 62 for developers
* Firefox 61 for developers
* Firefox 60 for developers
* Firefox 59 for developers
* Firefox 58 for developers
* Firefox 57 for developers
* Firefox 56 for developers |
Firefox 25 for developers - Mozilla | Firefox 25 for developers
=========================
Changes for Web developers
--------------------------
### New in Firefox DevTools
* The inspector now features autocompletion for CSS names and values.
* The debugger now lets you "black box" script files, to prevent breakpoints from stopping in library code you're not interested in debugging.
* The Profiler now has the ability to save and import profiling results. "Show Gecko Platform Data" is now an option in the Firefox developer tools options.
* The Network panel has a right-click context menu, with copy and resend URL commands.
* Numerous under-the-hood changes may make some rewriting necessary for addons that modify the DevTools.
### CSS
* The support for the keyword `local` as a value of the `background-attachment` CSS property has been added (Firefox bug 483446).
* Support of a non-standard Mozilla-only media query to determine the operating system version has been added: `-moz-os-version` (Firefox bug 810399). The property is currently only implemented on Windows.
* The `-moz-osx-font-smoothing` CSS property has been added (Firefox bug 857142).
* Our experimental support for `filter` now supports the `hue-rotate()` functional notation (Firefox bug 897392). It is still preffed off by default.
* `page-break-inside`: `avoid` is now working with the height of a block (Firefox bug 883676).
### HTML
* The `srcdoc` attribute of `<iframe>`, allowing the inline specification of the content of an `<iframe>`, is now supported (Firefox bug 802895).
* When used with a `"image/jpeg"` type, the method `HTMLCanvasElement.toBlob` now accepts a third attribute defining the quality of the image (Firefox bug 891884).
### JavaScript
ECMAScript 2015 implementation continues!
* The method `Array.of()` is now implemented on `Array` (Firefox bug 866849).
* Support for the methods `Array.prototype.find()` and `Array.prototype.findIndex()` has been added (Firefox bug 885553).
* The methods `Number.parseInt()` and `Number.parseFloat()` have been implemented (Firefox bug 886949)
* The methods `Map.prototype.forEach()` and `Set.prototype.forEach()` are now implemented (Firefox bug 866847).
* New mathematical methods have been implemented on `Math`: `Math.log10()`, `Math.log2()`, `Math.log1p()`, `Math.expm1()`, `Math.cosh()`, `Math.sinh()`, `Math.tanh()`, `Math.acosh()`, `Math.asinh()`, `Math.atanh()`, `Math.trunc()`, `Math.sign()` and `Math.cbrt()` (Firefox bug 717379).
* Support for binary and octal integer literals has been added: `0b10101010`, `0B1010`, `0o777`, `0O237` are now valid (Firefox bug 894026).
* The machine epsilon constant, that is the smallest representable number that added to 1 will not be 1, is now available as `Number.EPSILON` (Firefox bug 885798).
* Typed arrays have been updated to no longer search in the prototype chain for indexed properties (Firefox bug 829896).
### Interfaces/APIs/DOM
* The Web Audio API is now supported. An incomplete implementation was previously available behind a preference (Firefox bug 779297).
* Some IME related keys on Windows are supported by `KeyboardEvent.key` (Firefox bug 865565), see the key name table for the detail.
* Firefox for Metro now dispatches key events in the same way as the desktop version (Firefox bug 843236).
* `keypress` event is no longer dispatched if `preventDefault()` of preceding `keydown` event is called (Firefox bug 501496), see the document of `keydown` event for the detail.
* Renamed the `Future` interface to `Promise` (Firefox bug 884279).
* The `srcDoc` property on the `HTMLIFrameElement` interface, allowing the inline specification of the content of an `<iframe>`, is now supported (Firefox bug 802895).
* The `createTBody()` method on the `HTMLTableElement` interface, allowing to get its `<tbody>`, is now supported (Firefox bug 813034).
* The `Range.collapse()` method `toStart` parameter is now optional and default to `false`, as defined in the spec (Firefox bug 891340).
* Support of the `ParentNode` mixin on `Document` and `DocumentFragment` has been added (Firefox bug 895974).
* The `previousElementSibling` and `nextElementSibling` have been moved to the `ChildNode` mixin allowing them to be called not only on a `Element` object but also on a `CharacterData` or `DocumentType` object (Firefox bug 895974).
* The `navigator.geolocation` property has been updated to match the spec. It never returns `null`. When the preference `geo.enabled` is set to `false`, it now returns `undefined` (Firefox bug 884921).
* The `videoPlaybackQuality` attribute on the `HTMLVideoElement` interface has been changed to the `getVideoPlaybackQuality` method. (Firefox bug 889205)
* The non-standard `GlobalObjectConstructor` interface has been removed (Firefox bug 898136). This interface was used to add arguments to the constructors of APIs that Firefox add-ons were exposing on the global object. This capability has been removed; note that at this time there's no replacement for this functionality.
### MathML
*No change.*
### SVG
*No change.*
### Older versions
* Firefox 24 for developers
* Firefox 23 for developers
* Firefox 22 for developers
* Firefox 21 for developers
* Firefox 20 for developers
* Firefox 19 for developers
* Firefox 18 for developers
* Firefox 17 for developers
* Firefox 16 for developers
* Firefox 15 for developers
* Firefox 14 for developers
* Firefox 13 for developers
* Firefox 12 for developers
* Firefox 11 for developers
* Firefox 10 for developers
* Firefox 9 for developers
* Firefox 8 for developers
* Firefox 7 for developers
* Firefox 6 for developers
* Firefox 5 for developers
* Firefox 4 for developers
* Firefox 3.6 for developers
* Firefox 3.5 for developers
* Firefox 3 for developers
* Firefox 2 for developers
* Firefox 1.5 for developers |