Angular auto complete returns empty list

I am using AngularJS to generate auto completion. A list of values ​​to auto-complete will be provided using json. In my application, when I start typing, I get an empty list. All values ​​are empty. Here's my view code:

<md-autocomplete flex required
    md-input-name="un_registered[vehicle_attributes][brand_name]"
    md-no-cache="mainCtrl.noCache"
    md-selected-item-chang=""
    md-search-text-change=""
    md-selected-item="mainCtrl.selectedItem"
    md-search-text="mainCtrl.searchText"
    md-items="item in mainCtrl.querySearch(mainCtrl.searchText)"
    md-item-text="item.display"
    md-floating-label="Brand" id="un_registered_vehicle_attributes_brand_name">
  <md-item-template>
    <span md-highlight-text="mainCtrl.searchText">{{item.display}}</span>
  </md-item-template>
  <div ng-messages="searchForm.autocompleteField.$error" ng-if="searchForm.autocompleteField.$touched">
    <div ng-message="required">You <b>must</b> have a favorite state.</div>
    <div ng-message="minlength">Your entry is not long enough.</div>
    <div ng-message="maxlength">Your entry is too long.</div>
  </div>
</md-autocomplete>

      

        
        
        
      

    

Here's my function querySearch

:

mainCtrl.querySearch = querySearch;

function querySearch(query) {
    return $http.get("/panel/all_brands.json")
        .then(function(result) {
            return result;
        });
}

      

        
        
        
      

    

My json data:

["Example Brand","abcdd","Example Brand2Hh","rr","ffff"]

      

        
        
        
      

    

What could be the problem?