title: failed to display data in $firebaseArray
body: <p>I tried to display my firebase data on html through $firebaseArray. Why is there nothing to display?</p>
  
  <p>My data is like(viewed on the firebase dash),</p>
  
  <p><a href="https://i.stack.imgur.com/eHO8u.png" rel="nofollow noreferrer"><img src="https://i.stack.imgur.com/eHO8u.png" alt="enter image description here"></a></p>
  
  <p>My code is roughly like such(not complete, but I think it is enough to demo the problem),
  <a href="http://jsfiddle.net/bp6cp0sh/3/" rel="nofollow noreferrer">http://jsfiddle.net/bp6cp0sh/3/</a></p>
  
  <p>html:</p>
  
  <pre><code>&lt;body ng-app = "testApp"&gt;
      &lt;div ng-controller="angularfirecontroller"&gt;
          &lt;ul&gt;
              &lt;li np-repeat="message in messages"&gt;
                  {{message.user}}
              &lt;/li&gt;
          &lt;/ul&gt;
      &lt;/div&gt;
  &lt;/body&gt;
  </code></pre>
  
  <p>javascript:</p>
  
  <pre><code>var testApp = angular.module("testApp", ["firebase"]);
  testApp.controller("angularfirecontroller", function($scope, $firebaseArray){
  
      var dataRef = new Firebase("https://boiling-inferno-1234.firebaseio.com/messages");
  
      $scope.messages = $firebaseArray(dataRef);
  
  });
  </code></pre>