Q:

how to make nice rewrited urls from a router

I'm making a toolkit for php applications. I've a made a routing system based on some conventions, it works well but i would like to learn how to make mod_rewrite rules or any other stuff to finally make the url good to see and good for seo.
The route system starts from a config file that set the app and url roots.
$app_root = $_SERVER["DOCUMENT_ROOT"].dirname($_SERVER["PHP_SELF"])."/";
$app_url = $_SERVER['REQUEST_SCHEME'].'://'.$_SERVER['HTTP_HOST'].dirname($_SERVER['PHP_SELF']).'/';
define("APP_URL",$app_url);
define("APP_ROOT",$app_root);

The route always get start from index.php, wich makes instances of controllers@actions from GET parameters controllers=?&action=?
This is the index.php
    <?php
include_once 'controller/Frontend.php';
require 'libraries/Router.php';
$params=array();
    if(isset($_GET['controller'])&&isset($_GET['action'])){
        $c = $_GET['controller'];   
        $a = $_GET['action'];    
        // add all query string additional params to method signature i.e. &id=x&category=y
        $queryParams = array_keys($_GET);
        $queryValues = array_values($_GET);
            for ($i=2;$i<count($queryParams);$i++) {
                $params[$queryParams[$i]] = $queryValues[$i];   
            }

    if ($_POST) {
    // add all query string additional params to method signature i.e. &id=x&category=y
    $queryParams = array_keys($_POST);
    $queryValues = array_values($_POST);
            for ($i=0;$i<count($_POST);$i++) {
                $params[$queryParams[$i]] = $queryValues[$i];   
            }
            }
    include_once APP_ROOT."/controller/$c.php";
    $controller = new $c();
    $controller->$a($params);

    }  else {   
    //attiva controller predefinito    
    $controller = new Frontend();
    $controller->index();
    }

This allow to select what controller and what action the router must call.
The router function here get the APP URL from settings.php in the root. You give im the two controllers@action params as string and it make the URL like so:
index.php?controller=X&action=Y&[params...]
<?php

require './settings.php';
    function router($controller,$action,$query_data="") {
    $param = is_array($query_data) ? http_build_query($query_data) : "$query_data";
    $url = APP_URL."index.php?controller=$controller&action=$action&$param";
    return $url;
}
    function relativeRouter ($controller,$action,$query_data=""){
    $param = is_array($query_data) ? http_build_query($query_data) : "$query_data";
    $url = "index.php?controller=$controller&action=$action&$param";
    return $url;
}
    function redirectToOriginalUrl() {
        $url = $_SERVER['HTTP_REQUEST_URI'];
        header("location: $url");
    }

    function switchAction ($controller, $action) {
        $r = router($controller, $action);
        header("location:$r", true, 302);
    }

In templates file i call router('controller,'action') to retrive url's to actions and also pass GET/POST data (collected from index.php that put's them into the method signature as array).
Don't blame me for using global POST/GET without filtering i'm still developing the thing, security things will be made after ;)
What i would like to ask if someone could share some thoughts on how to make pretty urls like site/page/action....
For example www.site.com/blog/post?id=1
(Actually the N params in the router function ($query_data) works this way, you pass array['id' => '1'] and you get ?id=1)
What are best strategies to make good urls?
Thank you so much, still learning PHP. 
If there are best way to do such things just give your feedback.

A:

I found myself an answer to the question, i post here maybe it's useful.
I've added a .htaccess file in the root:
Options -MultiViews
RewriteEngine On
RewriteCond %{REQUEST_FILENAME} !-f
RewriteRule ^ index.php [QSA,L]

This will return each request to the root/index.php file.
Index file collect routes from the HTTP request, check if the route exist in the "routes.json" file.
URL are written in this way:
site.com/controller/action. GET params are written as follows
site.com/controller/action/[params]/[value]...... This output for example site.com/blog/post/id/1
That should be also fine for REST.
Here the index.php
    <?php
require 'controller/Frontend.php';
require 'Class/Router.php';

//require 'libraries/Router.php';
/*
 * ** ROUTING SETTINGS **
 */
$app_root = $_SERVER["DOCUMENT_ROOT"].dirname($_SERVER["PHP_SELF"])."/";
$app_url = $_SERVER['REQUEST_SCHEME'].'://'.$_SERVER['HTTP_HOST'].dirname($_SERVER['PHP_SELF']).'/';
define("APP_URL",$app_url);
define("APP_ROOT",$app_root);

$basepath = implode('/', array_slice(explode('/', $_SERVER['SCRIPT_NAME']), 0, -1));
$uri = substr($_SERVER['REQUEST_URI'], strlen($basepath));
//echo $uri;
if ($uri == "/") {
    $frontend = new Frontend();
    $frontend->index();
} else {
    $root = ltrim ($uri, '/');
    //$paths = explode("/", $uri);
    $paths = parse_url($root, PHP_URL_PATH);
    $route = explode("/",$paths);
    $request = new \PlayPhp\Classes\Request();
    // controller
    $c = $route[0];
    // action
    $a = $route[1];

    $reverse = Router::inverseRoute($c,$a);

    $rest = $_SERVER['REQUEST_METHOD'];
    switch ($rest) {
        case 'PUT':
            //rest_put($request);
            break;
        case 'POST':
            if (Router::checkRoutes($reverse, "POST")) {
                foreach ($_POST as $name => $value) {
                    $request->setPost($name,$value);
                }
                break;
            } else {
                Router::notFound($reverse,"POST");
            }
        case 'GET':
            if (Router::checkRoutes($reverse, "GET")) {
                for ($i = 2; $i < count($route); $i++) {
                    $request->setGet($route[$i], $route[++$i]);
                }
                break;
            } else {
                Router::notFound($reverse,"GET");
            }
            break;
        case 'HEAD':
            //rest_head($request);
            break;
        case 'DELETE':
            //rest_delete($request);
            break;
        case 'OPTIONS':
            //rest_options($request);
            break;
        default:
            //rest_error($request);
            break;
    }

    include_once APP_ROOT.'controller/'.$c.'.php';
    $controller = new $c();
    $controller->$a($request);

}

The Router class:
    <?php

include 'config/app.php';
/*
 * Copyright (C) 2015 yuri.blanc
*/
require 'Class/http/Request.php';
class Router {
    protected static $routes;

    private function __construct() {
        Router::$routes = json_decode(file_get_contents(APP_ROOT.'config/routes.json'));
    }

    public static function getInstance(){
        if (Router::$routes==null) {
           new Router();
        }
        return Router::$routes;
    }

    public static function go($action,$params=null) {
        $actions = explode("@", $action);
        $c = strtolower($actions[0]);
        $a     = strtolower($actions[1]);
        // set query sting to null
        $queryString = null;
        if(isset($params)) {

            foreach ($params as $name => $value) {
                $queryString .= '/'.$name.'//'.$value;
            }

            return APP_URL."$c/$a$queryString";
        } 
        return APP_URL."$c/$a";
    }

     public static function checkRoutes($action,$method){
         foreach (Router::getInstance()->routes as $valid) {
          /*   echo $valid->action . ' == ' . $action . '|||';
             echo $valid->method . ' == ' . $method . '|||';*/
             if ($valid->method == $method && $valid->action == $action) {
                 return true;
             }
         }
     }

    public static function inverseRoute($controller,$action) {
        return ucfirst($controller)."@".$action;
    }
    public static function notFound($action,$method) {

        die("Route not found:: $action with method $method");

    }

}

I use the json_decode function to parse the json object in stdClass().
The json file looks like this:
    {"routes":[
  {"action":"Frontend@index", "method":"GET"},
  {"action":"Frontend@register", "method":"GET"},
  {"action":"Frontend@blog", "method":"GET"}
]}

This way i can whitelist routes with their methods and return 404 errors while not found.
System is still quite basic but gives and idea and works, hope someone will find useful.

