OnClientRating

The OnClientRating event is raised just before you click an item of the RadRating control. It is cancellable and precedes the OnClientRated event. If you cancel it the OnClientRated event is not raised, nor is a postback initiated if the AutoPostBack property is true.

You can use this event to prevent the rating operation based on certain criteria (e.g. the user has rated already). Canceling this event will prevent setting the value of the rating control.

The event handler receives two arguments:

1. Sender – the RadRating object that fired the event.

2. Event arguments – an event arguments object that exposes the following properties and methods:

Client-side methods of the event arguments object.

Name	Parameters	Return Type	Description
get_cancel		bool	The method returns an object of type boolean. It indicates whether the event is canceled.
get_newValue		number	The method returns an object of type number. It shows the value that will be set to the control if the rating is not canceled.
set_cancel	bool		The method takes a boolean value that indicates whether the event will be canceled. In Example 1 you can check how to cancel the rating if a user has already used the control.

Example 1 : Using the OnClientRating event.

<telerik:RadRating RenderMode="Lightweight" runat="server" ID="RadRating2" OnClientRating="OnClientRating"></telerik:RadRating>
<script type="text/javascript">
    var isRated = false;
    function OnClientRating(sender, args) {
        args.set_cancel(isRated);
        if (!isRated) isRated = true;
    }
</script>