title: Get the key and value of ng-repeat
body: <p>Is there a way to get the 'key' of ng-repeat in scope.$watch</p>
  
  <pre><code>&lt;div ng-repeat="(key, contents_extended_data) in moderation.contents"&gt;
     &lt;img src="" id='target_photo_[[contents_extended_data.reference]]'&gt;
  &lt;/div&gt;
  
  // I can't find any variable that can get the value of the key in Angular documentation
  scope.$watch('$index',function(v){
      // do something here using the id of the image
      $('#target_photo_' + v)
  });
  </code></pre>
  
  <p>Thanks in advance</p>