OnClientNodePopulationFailed

The OnClientNodePopulationFailed client-side event occurs when:

• Child nodes are loaded on-demand.

• The parent node ExpandMode property is ServerSideCallback or WebService.

• An exception occurs while loading.

The event handler receives parameters:

1. The TreeView instance that fired the event.

2. Event arguments with functions:

• get_node() retrieves a reference to the parent node.

• get_errorMessage() retrieves the exception message text.

• set_cancel() - call this function to specify whether the event should be canceled (true) or not (false). Canceling of the event will prevent the exception from propagating.

• get_domEvent() retrieves a DOM event object.

In the example below an exception is raised in the server-side NodeExpand event handler

ASPNET

<telerik:RadTreeView RenderMode="Lightweight" ID="RadTreeView1" runat="server" OnClientNodePopulationFailed="ClientNodePopulationFailed"
    OnNodeExpand="RadTreeView1_NodeExpand">
    <Nodes>
        <telerik:RadTreeNode runat="server" ExpandMode="ClientSide" Text="Search" ImageUrl="~/images/search.ico"
            Expanded="True" Value="1">
            <Nodes>
                <telerik:RadTreeNode runat="server" ExpandMode="ServerSideCallBack" Text="Recent Searches">
                </telerik:RadTreeNode>
                <telerik:RadTreeNode runat="server" ExpandMode="ServerSideCallBack" Text="Network Locations">
                </telerik:RadTreeNode>
            </Nodes>
        </telerik:RadTreeNode>
    </Nodes>
</telerik:RadTreeView>

JavaScript

function ClientNodePopulationFailed(sender, eventArgs) {

	var node = eventArgs.get_node();
	var message = eventArgs.get_errorMessage();
	
	alert("OnClientNodePopulationFailed fired for node " +
		node.get_text() +
		" with message[" +
		message + "]");
		
	eventArgs.set_cancel(true);
}

Note that the custom alert will appear on remote clients, only if the customErrors mode is set to Off in the web.config:

The server NodeExpand event handler for the RadTreeView defined above:

C#

protected void RadTreeView1_NodeExpand(object sender, Telerik.Web.UI.RadTreeNodeEventArgs e)
{    
    throw new ApplicationException("An error occurred while attempting to populate " + e.Node.Text);
}

VB.NET

Protected Sub RadTreeView1_NodeExpand(ByVal sender As Object, ByVal e As Telerik.Web.UI.RadTreeNodeEventArgs)
    Throw New ApplicationException("An error occurred while attempting to populate " + e.Node.Text)
End Sub

See Also

• OnClientNodePopulating

• OnClientNodePopulated

• RadTreeNode