Почему не работает фильтрация моих данных в сетке кендо

Question

Я пытаюсь реализовать фильтрацию на стороне сервера в сетке кендо.

У меня есть пост-запрос "/ api / Account / Filter", который возвращает данные фильтра, Я также проверил это в fiddler, что подразумевает его работу, но я не знаю, почему после вызова фильтра сетка кендо обновляется со всеми данными!

Вот мой код:

        $scope.DS = new kendo.data.DataSource({
            type: "json",
            transport: {
                read: {
                    url: "/api/Employees",
                    dataType: "json",
                    contentType: "application/json",
                    type: "GET",
                    headers: { 'Authorization': 'Bearer ' + sessionStorage.getItem("accessToken") }
                },
                update: {
                    url: "/api/Employees/PUT",
                    dataType: "json",
                    contentType: "application/json",
                    type: "PUT",
                    headers: { 'Authorization': 'Bearer ' + sessionStorage.getItem("accessToken") }
                },
                destroy: {
                    url: "/api/Employees/DELETE",
                    dataType: "json",
                    contentType: "application/json",
                    type: "DELETE",
                    headers: { 'Authorization': 'Bearer ' + sessionStorage.getItem("accessToken") } },
                create: {
                    url: "/api/Employees/POST",
                    dataType: "json",
                    contentType: "application/json",
                    type: "POST",
                    headers: { 'Authorization': 'Bearer ' + sessionStorage.getItem("accessToken") }  },
                parameterMap: function (options, operation) {
                    if (operation !== "read") {
                        console.log(JSON.stringify(options.models));
                        return JSON.stringify(options.models);
                    }}},
            batch: true,
            pageSize: 5,
            serverFiltering: true,
            schema: {
                model: {
                    id: "Id",
                   data: 'Data',
                   total: 'Total',
                  //  errors: 'Errors',
                    fields: {
             Id: { editable: false, nullable: false, type: "number" },
           Email: { editable: true, type: "string" },
            UserName: {editable: true,type: "string"},
   FirstName: { editable: true, type: "string" },
     LastName: { editable: true, type: "string"},
   Age: { editable: true,  validation: { required: true } },
   Phone: { editable: true, validation: { required: true } },
     Department: { editable: true,type: "string"}
     } }
            },
        });

        $scope.mainGridOptions = {
            dataSource: $scope.DS,
            dataBound: function () {
  var data = this.dataSource.view();
            },
            toolbar: ["create"],
            columns: [
                { field: "Email", title: "Email", width: "100px" },
                { field: "UserName", title: "User Name", width: "100px"},
               { field: "FirstName", title: "First Name", width:"100px"},
             { field: "LastName", title: "Last Name", width: "100px" },
                { field: "Phone", title: "Phone", width: "100px" },
                { field: "Age", title: "Age", width: "100px" },
             { field: "Department", title: "Department", width: "100px"},
                {
                    command: [{
                        name: "edit",
                        text: {
                            edit: "Edit",
                            update: "Save",
                            cancel: "Cancel"
                        }
                    }, "destroy"], title: "Actions", width: "150px"
                }
            ],
            filterable: true,
            pageable: {
                refresh: true,
                input: true,
                numeric: false,
                pageSizes: [5, 10, 20, 30, 50, 75, 100, 500, 1000]
            },
            sortable: true,
            resizable: true,
            navigatable: true,
            serverFiltering: true,
            editable: { mode: "inline" },
            filter: function (data) {
                console.log((data));
                console.log((data.filter));
                const requestOptions = {
                    headers: { 'Authorization': 'Bearer ' + sessionStorage.getItem("accessToken") }
                };
                $http.post("/api/Account/Filter", data, requestOptions).then(function (d) {
                    console.log(JSON.stringify(d.data.Data));
                    // $scope.DS.read = d.data.Data;
                    debugger;
                    $scope.mainGridOptions.dataSource.query(d.data.Data);

                }, function () {
                alert("Failed.Please try again.")
                    });
            },

            noRecords: { template: "No results available."}

        };

Следующий код находится в контроллере для получения всех данных:

  public List<RegisterBindingModel> GET()
        {
            var user = db.Users.Select(x => new RegisterBindingModel()
                {
                    Id = x.Id,
                    Email = x.Email,
                    UserName = x.UserName,
                    FirstName = x.FirstName,
                    LastName = x.LastName,
                    Age = x.Age,
                    Phone = x.Phone,
                    Department = x.Department
                });
                return user.ToList();

Это для фильтра на стороне сервера:

[AcceptVerbs("GET","POST")]
    public IHttpActionResult Filter(Models.DataSourceRequest request)
    {
        request.Skip = 0;
        request.Take = 5;
        if (request != null)
        {
            request.Filter.Field = request.Filter.Filters.FirstOrDefault().Field;
            request.Filter.Operator = request.Filter.Filters.FirstOrDefault().Operator;
            request.Filter.Value = request.Filter.Filters.FirstOrDefault().Value;
            var o = request;
        }
        var employees = db.Users.OrderBy(ii => ii.Id).Select(x => new RegisterBindingModel()
        {
            Id = x.Id,
            Email = x.Email,
            UserName = x.UserName,
            FirstName = x.FirstName,
            LastName = x.LastName,
            Age = x.Age,
            Phone = x.Phone,
            Department = x.Department
        });
        var i = employees.ToDataSourceResult(request.Take, request.Skip, request.Sort, request.Filter);
        var data = i.Data; // This is contain filtered data
        request.Take = i.Total;
        var d = Json(data);
        return Json(new { Data = data, Total = request.Take });
        //return data.Cast <RegisterBindingModel>().ToList();
    }

Не могли бы вы сказать мне, что я делаю не так?