TypeError: Cannot read property '$$hashKey' of undefined
<p>I have an object return by http post in angular</p>

<pre><code>var altest = {

//here I have an empty object prepared to be extend

  Detail: {}

init : function(passdata) {

  var self = this;

  var dataResult = self.getVacanshitDetail(passdata);   

  console.log(dataResult);

  self.Detail = dataResult;

  console.log(self.Detail );
  //return self.Detail .info;
},

  getVacanshitDetail: function(passdata) {
    var self = this;      
    $http.post(Constants.API.baseUrl).success( function(response) {
        console.log(response);
        angular.extend(self.Detail,response);
    });
  },
</code></pre>

<p>However, in the extend line, in the console log it says: <strong>TypeError: Cannot read property '$$hashKey' of undefined</strong></p>

<pre><code>//object response from http request 

Object {
    title:  'Frog',
    url:    '/img/picture.jpg',
    width:  300,
    height: 200
  };
</code></pre>

<p>Please help what I need to do to achieve what I want and avoid the error. </p>

<p>Many thanks in advance. </p>