Select2 with Laravel 5.1

最近测试Jquery插件select2 多数功能都可以实现，但是Ajax始终没办法实现。若是有同学用过，请传授下。
我要实现城市名称的自动完成，类似携程或者去哪儿填写目的地一样。
前端JS代码

$(".js-data-example-ajax").select2({
  ajax: {
    type: 'POST',
    url: "https://ajax.dev", //这是我的测试地址，已经更改Host
    dataType: 'json',
    delay: 200,
    headers: {'X-CSRF-TOKEN': $('meta[name="_token"]').attr('content')},
    data: function (params) {
      return {
        location: params.term,
      };
    },
    processResults: function (data, params) {
      // parse the results into the format expected by Select2
      // since we are using custom formatting functions we do not need to
      // alter the remote JSON data, except to indicate that infinite
      // scrolling can be used
      params.page = params.page || 1;
 
      return {
        results: data.items,
        pagination: {
          more: (params.page * 30) < data.total_count
        }
      };
    },
    cache: true
  },
  escapeMarkup: function (markup) { return markup; }, // let our custom formatter work
  minimumInputLength: 2,
  templateResult: formatRepo, // omitted for brevity, see the source of this page
  templateSelection: formatRepoSelection // omitted for brevity, see the source of this page
});

服务器Laravel Controller 代码

public function ajax(Request $request){

$keywords=$request->term; 

$result=DB::table('locations')->where('name','like',"%$keywords%")->get();

return $result;
}