title: prevent angular update from overriding updated form data
body: <p>When performing an update using ngResource, any changes the user makes to the form between when the update is sent and received is lost when the update returns.  </p>
  
  <p>What can I do to ensure that any changes to the form remain when the update returns?</p>
  
  <p>Here is an example to better explain the issue.</p>
  
  <pre><code>var app = angular.module('app', ['ngResource'])
  .factory('cartService', function($resource) {
      return $resource('/cart/items/:id ', { id: '@id' },{'update': { method:'PUT' }});
  });
  
  app.controller('cart', function($scope, $timeout, cartService, availabilityService) {
    //Initial Data
    $scope.item = cartService.get({'id':'1'}, function(){
    $scope.item.note = "Test";
    //save on a slow server
    $scope.item.$update;
    //Customer changes value before server response is received
    $scope.item.note = "For Customer X"
    //when server response is received the note is changed to "Test"
    });
  </code></pre>