title: In the angular-ui-grid,how do I use rowSelectionChanged with vm instead of $scope?
body: <p>I want to use:</p>
  
  <pre><code>gridApi.selection.on.rowSelectionChanged(vm, callBackFunction) 
  </code></pre>
  
  <p>instead of:</p>
  
  <pre><code>gridApi.selection.on.rowSelectionChanged($scope, callBackFunction)
  </code></pre>
  
  <p>When I do it causes an error.</p>