title: Change the ngModel value from a directive
body: <p>I am using AngularJS and I created a directive that requires 'ngModel':</p>
  
  <pre><code>'use strict';
  angular.module('spot.im.embed').directive('sayBox', ['$sce', '$timeout', '$parse',
      function($sce, $timeout, $parse) {
          return {
              restrict: 'EA',
              require: 'ngModel',
              scope: {
              },
              link: function(scope, iElement, iAttrs, ngModel) {
                  ngModel.$viewValue = 'adasd';
              }
          }
      }
  ]);
  </code></pre>
  
  <p>For reasons I don't know, the ng-model changes doesn't impact the view. Why is that? Is this the right way to change the ngModel value from a directive?</p>