Creating Context Menus at the Client

The built-in Context Menu of RadTreeView allows you to add Items at the client-side. The example below shows how to add a child Item upon clicking an existing Item:

function OnClientContextMenuItemClicked(sender, eventArgs)
{  
  var item = eventArgs.get_menuItem();
  var menu = item.get_menu();            
  sender.trackChanges();
  var newItem = new Telerik.Web.UI.RadMenuItem();
  newItem.set_text("Client-side added item");
  item.get_items().add(newItem);
  sender.commitChanges();
}