TreeView / Client-side events

You can attach to the RadTreeView's events by using either the server-side properties or the client-side API.

1. Attaching event handlers via a server-side property
   Each client-side event has a corresponding property, whose name is formed like OnClient[EventName].
   You can set the property to the name of the function to be called when the event occurs.

   <telerik:RadTreeView ID="RadTreeView1" runat="server" OnClientNodeClicking="onNodeClicking" />
   
   <script type="text/javascript">
   	function onNodeClicking(sender, args)
   	{
   		 logEvent("OnClientNodeClicking: " + args.get_node().get_text());
   	}
   </script>
   		

2. Using the client-side API to attach event handlers
   Using the client-side API of RadTreeView allows you to attach multiple event handlers to one event using the standard MS AJAX conventions.

   <script type="text/javascript">
   	function onClickedHandler1()
   	{
   		alert("First handler called");
   	}
   	function onClickedHandler2()
   	{
   		alert("Second handler called");
   	}
   
   	function pageLoad()
   	{
   		var treeView = $find("<%=RadTreeView1.ClientID%>");
   		
   		treeView.add_nodeClicking(onClickedHandler1);
   		treeView.add_nodeClicking(onClickedHandler2);
   	}
   </script>
   

   Another advantage of the client-side API is the possiblity of dynamically detaching certain handlers. You can use the remove_nodeClicking method of the treeview object.
   
   

   <script type="text/javascript">
   	$find(<%=RadTreeView1.ClientID%>).remove_nodeClicking(onClickedHandler1);
   </script>
   

3. Cancelling an event
   The events, whose names end in ing, can be cancelled. You can cancel the event by using the set_cancel method of the event arguments passed to the handler.

   <script type="text/javascript">
   	function onClientNodeClicking(sender, eventArgs)
   	{
   	    eventArgs.set_cancel(true);
   	}