Q:

Directive to create a[download] button

I got help to save json as file in client side here. Code is very short as in this fiddle.
var a = document.createElement('a');
a.download    = "backup.json";
a.href        = url;
a.textContent = "Download backup.json";

document.getElementById('content').appendChild(a);

I was trying to create an angularjs directive so that it calls a method in scope to get the data. Along this line. 
module.directive('myDownload', function ($compile) {
    return {
        restrict:'E',
        scope:{ getData:'&getData'},
        link:function (scope, elm, attrs) {
            elm.append($compile(
                '<a class="btn" download="backup.json"' +
                    'href=' + scope.getData() + '>' +
                    'Download' +
                    '</a>'
            )(scope));
        }
    };
});

This doesn't work. How can make the linked fiddle into a directive?

A:

How about something like this: Fiddle
Here's the directive code:
module.directive('myDownload', function ($compile) {
  return {
    restrict:'E',
    scope:{ getUrlData:'&getData'},
    link:function (scope, elm, attrs) {
        var url = URL.createObjectURL(scope.getUrlData());
        elm.append($compile(
            '<a class="btn" download="backup.json"' +
                'href="' + url + '">' +
                'Download' +
                '</a>'
        )(scope));
     }
  };
});

Controller:
module.controller('MyCtrl', function ($scope){
  var data = {a:1, b:2, c:3};
  var json = JSON.stringify(data);

  $scope.getBlob = function(){
    return new Blob([json], {type: "application/json"});
  }
});

