Menu / Web Service

RadMenuItems can be populated via a WebService. This example shows how to dynamically load child items through a web service.

The path to the WebService's asmx file and the name of the service method are specified in the WebService-Path and WebService-Method properties of the RadMenu's WebServiceSettings tag. You also need to set the ExpandMode of the items, which are supposed to load their children through a WebService, to "WebService". Optionally, you can handle the itemPopulating, itemPopulated and itemPopulationFailed client-side events. In addition, you can use the LoadingStatusTemplate property to create a loading template.

    <telerik:RadMenu ID="RadMenu1" runat="server" OnClientItemPopulating="itemPopulating">
        <WebServiceSettings Path="ProductCategories.asmx" Method="GetMenuCategories" />
        <LoadingStatusTemplate>
           ...
        </LoadingStatusTemplate>
        <Items>
            <telerik:RadMenuItem Text="Products" Value="1" ExpandMode="WebService"/>        
             ...
        </Items>
    </telerik:RadMenu>

To use the integrated WebService support of RadMenu, the WebService should have the following signature:

[ScriptService]
public class WebServiceName : WebService
{
	[WebMethod]
	public RadMenuItemData[] WebServiceMethodName(RadMenuItemData item, object context)
	{
        	// We cannot use a dictionary as a parameter, because it is only supported by script services.
		// The context object should be cast to a dictionary at runtime.
		IDictionary<string, object> contextDictionary = (IDictionary<string, object>) context;
		
		//...
	}
}

The itemPopulating event can be used to pass parameters from the client-side to the WebService by using the "context" dictionary object.

function itemPopulating(sender, eventArgs)
{
	var item = eventArgs.get_item();
	var context = eventArgs.get_context();
	context["CategoryID"] = item.get_value();
}