title: When Invoke Filter by js in angular its return null
body: <p>Im new in Angular, And Im try to Using filter by JavaScript in angularJS, But Im get null..</p>
  
  <pre><code>app.controller('aneesFilters', function($filter){
      this.filterItem = filterItems;
      this.filterJSItem = $filter('currency')(filterItems, 'price');
  
  });
  
  var filterItems = [
      {price: 1254},
      {price: 154},
      {price: 963},
      {price: 1880},
  ];
  </code></pre>
  
  <p>html code: </p>
  
  <pre><code>    &lt;div ng-controller="aneesFilters as filter"&gt;
          &lt;div ng-repeat="item in filter.filterItem"&gt;
              &lt;div&gt;{{item.price | currency}}&lt;/div&gt;
              &lt;div&gt;{{item.price | currency:"JOD"}}&lt;/div&gt;
              &lt;div&gt;{{item.price | currency:"JOD":0}}&lt;/div&gt;
              &lt;hr /&gt;
          &lt;/div&gt;
  
          &lt;h2&gt;By javascript (Used filter in controller)&lt;/h2&gt;
          &lt;div ng-repeat="item in filter.filterJSItem"&gt;
              &lt;div&gt;{{item.price}}&lt;/div&gt;
              &lt;hr /&gt;
          &lt;/div&gt;
      &lt;/div&gt;
  </code></pre>
  
  <p>surly, code work when Im using filter on Expression, problem was happened when call FilterJsItem ..</p>
  
  <p>thanks a lot.  </p>