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OnClientItemsRequesting

The OnClientItemsRequesting client-side event occurs when EnableLoadOnDemand is True and the combobox is about to send a server-side request to load more items. This event fires before the items are added to the combobox' Items collection.

The event handler receives two parameters:

  1. The instance of the combobox firing the event.

  2. An eventArgs parameter containing the following methods:

  • get_text returns the text currently in the input area.

  • get_context returns a context object (implements IDictionary) that is passed to the server-side code that handles the request for items.

  • set_cancel lets you prevent the items request.

  • get_domEvent() returns the DOM event object.

This event can be used to pass context information to the server for it to use in servicing the load-on-demand request, or to cancel the load-on-demand request. The following example uses the OnClientItemsRequesting event to prevent the combobox from requesting more items unless the user types at least three characters:

<script language="javascript" type="text/javascript">
    function OnClientItemsRequesting(sender, eventArgs) {
        if (eventArgs.get_text().length < 3)
            eventArgs.set_cancel(true)
        else
            eventArgs.set_cancel(false);
    }
</script>
<telerik:RadComboBox
  ID="RadComboBox1"
  runat="server"
  EnableLoadOnDemand="True"
  OnItemsRequested="RadComboBox1_ItemsRequested"
  OnClientItemsRequesting="OnClientItemsRequesting">
</telerik:RadComboBox> 

See Also