Cancel AJAX Requests with the AjaxManager or AjaxPanel

Environment

Product

Progress® Telerik® UI for ASP.NET AJAX AjaxManager

Progress® Telerik® UI for ASP.NET AJAX AjaxPanel

Description

How can I cancel an Ajax request with the Telerik UI for ASP.NET AjaxManager or AjaxPanel?

Solution

To cancel an AJAX request, in the OnRequestStart client-side event handler of the AjaxManager or AjaxPanel, call the set_cancel(true) to prevent the request from continuing.

JavaScript

<telerik:RadCodeBlock ID="RadCodeBlock1" runat="server">
	<script type='text/javascript'>
	            function OnRequestStart(ajaxPanel, eventArgs) {
	                var eventTarget = eventArgs.get_eventTarget();
	                if (eventTarget == "<%= Button1.UniqueID %>") {
	                    if (!CheckZipCode()) {
	                        eventArgs.set_enableAjax(false); // cancel the ajax request
	                    }
	                }
	            }
	
	            function CheckZipCode() {
	                var zipCode = $get('<%= TextBox1.ClientID %>').value;
	                if (zipCode.length != 5) {
	                    alert('Please enter a valid 5 digit postal code!');
	                    return false;
	                }
	                else {
	                    var fiveDigitCheckRE = /^\d{5}$/ //regular expression for checking a 5 digit number
	                    if (zipCode.search(fiveDigitCheckRE) == -1) {
	                        alert("Only digits are allowed!");
	                        return false;
	                    }
	                }
	                return true;
	            }
	 </script>
</telerik:RadCodeBlock>

See Also

• Client Confirmation and AJAX

• Cancelling AJAX