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The OnClientItemPopulating client-side event occurs when the menu is about to call a Web service to populate the child items of an item with ExpandMode set to "WebService".

The event handler receives two parameters:

  1. The instance of the menu firing the event.

  2. An eventArgs parameter containing the following methods:

  • get_item returns a reference to the RadMenuItem whose child items are about be populated from the Web service.

  • set_cancel lets you prevent the call to the Web service.

  • get_cancel returns a boolean value indicating whether the call to the Web service was canceled.

  • get_context returns a reference to an IDictionary object that can be used to pass context information to the Web service.

  • get_domEvent returns a reference to the DOM event.

You can use this event to conditionally cancel the call to fetch items or to pass context information to the Web service before the call:

<script type="text/javascript">
    function itemPopulating(sender, eventArgs) {
        var item = eventArgs.get_item();
        var context = eventArgs.get_context();
        context["CategoryID"] = item.get_value();

<telerik:RadMenu RenderMode="Lightweight" ID="RadMenu1" runat="server" Skin="Default" OnClientItemPopulating="itemPopulating">
    <WebServiceSettings Path="ProductCategories.asmx" Method="GetMenuCategories" />
        <asp:Image runat="server" ID="LoadingImage" ImageUrl="~/Ajax/Img/loading7.gif" ToolTip="Loading..."
            Width="81px" Height="21px" />
        <telerik:RadMenuItem Text="Products" Value="1" ExpandMode="WebService">
        <telerik:RadMenuItem Text="Purchase" Value="132" ExpandMode="WebService">
        <telerik:RadMenuItem Text="Support" Value="141" ExpandMode="WebService">
        <telerik:RadMenuItem Text="Community" Value="155" ExpandMode="WebService">
        <telerik:RadMenuItem Text="Corporate" Value="164" ExpandMode="WebService">

See Also

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