angularjs - filters stopped working ..shows blank page -

when click headers, not sort , table disappears

angular.module('maniaapp')   .controller('eventctrl', function ($scope,$location,$http) {       $scope.sorttype     = '_source.event_name'; // set default sort type     $scope.sortreverse  = false;  // set default sort order     $scope.searchevent   = '';     // set default search/filter term      var url = "http://api.loc/events/get-events";      $http.get(url).success(function api(data, status, headers, config){       $scope.events = data;     }).error(function api(data, status, headers, config){       console.error(data, status, headers, config);     }); 

here html

<div class="container">   <!--<div ng-view=""></div>-->   <div ng-controller="eventctrl">     <div class="alert alert-info">       <p>sort type: {{ sorttype }}</p>       <p>sort reverse: {{ sortreverse }}</p>       <p>search query: {{ searchevent }}</p>     </div>      <form>       <div class="form-group">         <div class="input-group">           <div class="input-group-addon"><i class="fa fa-search"></i></div>            <input type="text" class="form-control" placeholder="search events" ng-model="searchevent">          </div>       </div>     </form>     <table class="table table-bordered table-striped">        <thead>       <tr>         <td>           <a href="#" ng-click="sorttype = '_source.id'; sortreverse = !sortreverse">             id             <span ng-show="sorttype == '_source.id';" class="fa fa-caret-down"></span>           </a>         </td>         <td>           <a href="#" ng-click="sorttype = '_source.event_name'; sortreverse = !sortreverse">             <span ng-show="sorttype == '_source.event_name';" class="fa fa-caret-down"></span>             event name           </a>         </td>         <td>           <a href="#" ng-click="sorttype = '_source.event_status_id'; sortreverse = !sortreverse">             <span ng-show="sorttype == '_source.event_sid'" class="fa fa-caret-down"></span>             event status           </a>         </td>       </tr>       </thead>        <tbody>       <tr ng-repeat="event in events | orderby:sorttype:sortreverse | filter:searchevent">         <td>{{ event._source.event_id }}</td>         <td>{{ event._source.event_name }}</td>         <td>{{ event._source.event_sid }}</td>       </tr>       </tbody>      </table>   </div> </div>