title: Dropzone.js callback access Angular scope
body: <p>I've built a simple AngularJS directive to implement Dropzone.js on elements.
  I'd like to display uploaded files using an ng-repeat outside of the directive, but I can't make it work since the 'addedfile' callback of the element seems to be creating a copy of the array (scope.files). The callback can read the array (or the copy of the array) but when I push a new element on it doesn't affect the ng-repeat. How can I make it work ?</p>
  
  <pre><code>.directive('dropzone', function() {
      return {
          restrict: 'EA',
          link: function(scope, el, attrs) {
  
              el.dropzone({
                  url: attrs.url,
                  maxFilesize: attrs.maxsize,
                  init: function() {
                      scope.files.push({file: 'added'}); // here works
                      this.on('success', function(file, json) {
                      });
                      this.on('addedfile', function(file) {
                          scope.files.push({file: 'added'}); // here doesn't work
                      });
                  }
              })
          }
      }
  });
  </code></pre>