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The OnClientRequesting client-side event occurs right before RadAutoCompleteBox sends a server-side request to load items into its drop-down container.

The event handler receives two parameters:

  1. The instance of RadAutoCompleteBox firing the event.

  2. An eventArgs parameter containing the following methods:

  • get_cancel() - returns a boolean value indicating whether the event has been canceled.

  • set_cancel(boolean) - cancels the event depending on the value passed as an argument.

  • get_context() - returns an object representing the context of the request.The object returned by get_context() method has a propery named 'Text' which contains thetext currently present in the input area. This object is also used to pass context information to the server when a request to the server is initiated by assigning a value to its 'Text' property.

get_context() method of the EventArgs parameter is used only when RadAutoCompleteBox is bound to Web service.

This event is used in scenarios when operations need to be preformed to RadAutoCompleteBox right before a request to the server is initialized, or when the request needs to be canceled.

<script type="text/javascript">
    function requesting(sender, eventArgs) {
        if (sender.get_text().length < 3) {
<telerik:RadAutoCompleteBox RenderMode="Lightweight" runat="server" ID="RadAutoComplete1" OnClientRequesting="requesting"
    DataSourceID="SqlDataSource1" DataTextField="Name" DataValueField="ID">

<asp:SqlDataSource ID="SqlDataSource1" runat="server" ConnectionString="<%$ ConnectionStrings:TelerikVSXConnectionString %>"
    SelectCommand="SELECT [ID], [CountryID], [Name] FROM [Cities]">

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