Client Events Overview

Updated on Aug 31, 2026

This article explains how to attach client event handlers to an WebForms wrapper of the HTML5 Report Viewer instance.

To attach a client event handler you have to set the proper ClientEvents tag as shown below:

ASPX

<telerik:ReportViewer ID="reportViewer1" runat="server">
    <ClientEvents RenderingBegin="onRenderingBegin" />
</telerik:ReportViewer>

JavaScript

function onRenderingBegin() {
    console.log("rendering begin!");
}

The following table lists the available client events:

Event	Description
RenderingBegin	Occurs before rendering the report. For the underlying JS methods see RenderingBegin
RenderingEnd	Occurs after rendering the report. For the underlying JS methods see RenderingEnd
PrintBegin	Occurs before printing the report. For the underlying JS methods see PrintBegin
PrintEnd	Occurs after printing the report. For the underlying JS methods see PrintEnd
ExportBegin	Occurs before exporting the report. For the underlying JS methods see ExportBegin
ExportEnd	Occurs after exporting the report. For the underlying JS methods see ExportEnd
UpdateUi	Occurs on each UI update of the viewer. For the underlying JS methods see UpdateUi
Error	Error occurred. For the underlying JS methods see Error
PageReady	Occurs after a page of the report is ready. For the underlying JS methods see PageReady
Ready	Report viewer is ready. For the underlying JS methods see Ready
InteractiveActionExecuting	Occurs before an interactive action is executed, providing the ability to cancel the execution. For the underlying JS methods see InteractiveActionExecuting
InteractiveActionEnter	Occurs when the mouse cursor enters the area of an interactive action. For the underlying JS methods see InteractiveActionEnter
InteractiveActionLeave	Occurs when the mouse cursor leaves the area of an interactive action. For the underlying JS methods see InteractiveActionLeave
ViewerToolTipOpening	Occurs before a tooltip is opened, providing the ability to cancel its opening. For the underlying JS methods see ViewerToolTipOpening
SendEmailBegin	Occurs before the report is exported and the E-mail message is sent. For the underlying JS methods see SendEmailBegin
SendEmailEnd	Occurs after the report is exported and before the E-mail message is sent. For the underlying JS methods see SendEmailEnd