Unable to access Telerik radcombobox object in document onload in JavaScript in IE only

Question

When I try to access the Telerik radcombobox in document Onload, I am receiving the object as null in IE11 only. (works in edge, chrome and Firefox)

what is the best approach to access the radcombobox in document onload for IE.

$(document).ready(function () {
        var combo = $find("<%=radcombobox.ClientID%>");
        var items = combo.get_items();
}

Error: combo is Null

Answer 1

It is too early to get a reference to the Telerik AJAX control in the document onload event. Using native DOM events (like window.load or jQuery's $(document).ready may not give you the expected results. Such events are usualy prior to the Sys.Application.load event and cannot guarantee that the control instances are initialized.

The UI for ASP.NET AJAX controls are created by implementing the IScriptControl interface and have the lifecycle of MS AJAX-based controls. Thus, they are initialized during the Sys.Application.init event and the instance of the control can be accessed during the Sys.Application.load event at the earliest. You can see how in the Important MS AJAX Events section.

You can find more information at https://docs.telerik.com/devtools/aspnet-ajax/general-information/get-client-side-reference#using-jquery-selectors.