Unable to get property 'trackChanges' of undefined or null reference

[thomas]

Unable to get property 'trackChanges' of undefined or null reference in IE 9 and above and chrome.   No issues in IE 8.  Using jQuery on page load. 

var resultsDropDowlist = Terlerk.web.UI.RadComboBox.ComboBoxes[2];

resultsDropDownlist.trackChanges();

//To Clear the Selected Item

resultsDropDownList.get_items().clear();

[Ivan Danchev]

Hello Thomas,

You have two typos: Terlerk.web.UI.RadComboBox.ComboBoxes[2]; Should be Telerik.Web
Note however that you can get a reference to a RadComboBox control this way not to a RadDropDownList. If you want to get the RadDropDownList object, which is different from the RadComboBox one, we recommend doing so as shown in the documentation.


Regards,
Ivan Danchev
Telerik by Progress

[thomas]

Thanks for the reply Ivan.

Sorry about the typo but it was correct in code. 

var resultsDropDownList = Telerik.Web.UI.RadComboBox.ComboBoxes[2];

In IE 8 the jquery code will find the RadComboBox but in other versions above and in chrome it will fail.

[Ivan Danchev]

Hello Thomas,

This exception could indicate the ComboBox you are trying to get a reference to is not yet instantiated by the moment you are trying to access it.
I attached a sample runnable page to this reply, which shows that a proper reference is obtained in the page's Load event, in the control's own OnClientLoad client-side event's or in a button's click event. Could you modify it accordingly so that the issue is reproduced and post your modifications for further review?

Regards,
Ivan Danchev
Telerik by Progress

[thomas]

The issue was resolved by using

function pageLoad()  vs  $(document).ready(function()