Angularjs: backend query with $resource

app.html

<div class="row">
    <div class="col-xs-24">
        <div class="panel panel-blue">
            <div class="panel-heading">
                <span class="panel-title">Issues</span>
                <a ng-href="#assets" class="btn btn-custom-orange pull-right"><small><span class="icon-expand">&nbsp</span></small>Expand</a>
            </div>

            <div class="panel-body">
                <div ng-controller="MyCtrl1" style="color:#555;">
                    
                    <table class="table">
                      <tr>
                        <th>Id</th>
                        <th>State</th>
                        <th>Reporter</th>
                      </tr>
                      <tr ng-repeat="gist in data.gists">
                        <td><a class="btn btn-custom-sky" ng-click="showIssue(gist.id)">{{gist.id}}</a></td>
                        <td>{{gist.description}}</td>
                        <td>{{gist.user.login}}</td>
                      </tr>
                    </table>
                </div>
            </div>
        </div>
    </div>
</div>

script.js

angular.module('relitagApp')
    .factory('Gist', function($resource){
        var apiUrl = 'https://api.github.com';
        var Gist = $resource(apiUrl + '/gists/:id', {
        },{
            //creating a custom method
            'update': { method:'PUT' }
        });
        return Gist ; 
    })
    .controller('MyCtrl1', ['$scope', 'Gist', function($scope, Gist) {
        // Instantiate an object to store your scope data in (Best Practices)
        $scope.data = {};
       
        Gist.query(function(response) {
          // Assign the response INSIDE the callback
          $scope.data.gists = response;
          //console.log(response);
        });
    
        $scope.showIssue = function(gistId){
            var gist = Gist.get({id: gistId},function(){
                //alert(gist.files);
                for(var filename in gist.files) {
                    console.log(filename);
                    $scope.data.gist = gist.files[filename].content;
                    break;
                }
                gist.description = "changed the description";
                Gist.update({id: gistId});
                var newGist = Gist.get({id: gistId},function(){
                    console.log(newGist.description);
                });

                


            });
        };
    }]);