Kendo dropdownlist produces TypeError: n.slice is not a function

Question

Do I need to define the schema? If so, what should that look like? My searches for this seem to only turn up js solutions, I'm looking for the syntax to define it in the editortemplate.

Shared/editortemplate:

@(
Html.Kendo().DropDownList()
.Name("SearchFunction")
.DataTextField("SearchFunctionDesc")
.DataValueField("SearchFunctionCode")
.DataSource(source =>
    {        
        source.Read(read => { 
            read.Action("GetSearchFunctions", "User");
        });
    })
    .OptionLabel("--Select a Search Function--")
    .AutoBind(false)
)

In the controller:

    public JsonResult GetSearchFunctions([DataSourceRequest] DataSourceRequest request)
    {
        var searchFuncs = AdminService.GetSearchFunctions();
        DataSourceResult result = searchFuncs.ToDataSourceResult(request);
        return Json(result, JsonRequestBehavior.AllowGet);
    }

And then my Dapper db query:

            var result = new List<SearchFunction>();
            using (var conn = new OracleConnection(DatabaseConnectionString))
            {
                conn.Open();
                string query = "select FUNCTION_ID, SEARCH_FUNCTION_CD, " +        
                        "SEARCH_FUNCTION_DESC, IS_ACTIVE " +
                         "from TBL_SEARCH_FUNCTIONS "; 
                result = conn.Query(query)
                    .Select(s => new SearchFunction
                    {
                        FunctionId = (int)s.FUNCTION_ID,
                        SearchFunctionCode = s.SEARCH_FUNCTION_CD,
                        SearchFunctionDesc = s.SEARCH_FUNCTION_DESC,
                        Active = s.IS_ACTIVE
                    }).ToList<SearchFunction>();
                conn.Close();
                return result;
            }

Answer 1

Rewrite your controller method like this:

public JsonResult GetSearchFunctions()
{
    var searchFuncs = cmsViewAdminService.GetSearchFunctions();
    return Json(searchFuncs, JsonRequestBehavior.AllowGet);
}

That should simplify that method as you don't need the DataSourceRequest (as @CSharper mentioned in the comment). Kendo DropDownLists, unlike the grids, don't require the DataSourceRequest class. This way, you can call the same JsonResult from a jQuery Ajax method if you needed to do so.