Bug report

The Kendo UI Sortable for ASP.NET Core assumes that all selectors are by "id".

Reproduction of the problem

1. Set the .For() option of the Sortable widget to a class selector:

@(Html.Kendo().Sortable()
    .For(".k-grid table")
    // . . . 
)

2. Inspect the page source.

3. The following string is rendered:

<script>
    kendo.syncReady(function () { jQuery("\\.k-grid table").kendoSortable(// options) });
</script>

Expected/desired behavior

The Sortable widget should allow for passing any jQuery selectors.

Environment

* **Kendo UI version:** 2019.3.1023
* **jQuery version:** 1.12.4
* **Browser:** [all] 

Hi Kendo Team,

I am working on Kendo UI ASP.NET Core Grid binding with SignalR. But while starting Hub and providing the Promise, I am facing an error "The "promise" option must be a Promise."

I am following this URL for reference: https://demos.telerik.com/aspnet-core/grid/signalr .

Checked on your website as well, but the issue is also coming there. Here is the URL: https://docs.telerik.com/kendo-ui/api/javascript/data/datasource/configuration/transport.signalr

In this link, when clicking on "Open In Dojo" button, it opens a new window, then clicks on the Run button. It will generate an error in the console "Uncaught Error: The "promise" option must be a Promise.". 

Please check the attached snapshot.

Please reply asap. Thanks in advance!