Bit #37 - Preventing client events from propagating to the server

ADF Faces client events, i.e. events delivered and implemented on the browser using JavaScript,  by default do propagate to the server. There might be cases however that you don't want this default propagation. For instance, consider an af:commandButton component that defines a clientListener but has no actionListener defined. In this case propagating the client event to the server would be unnecessary. To stop the client event from propagating to the server use the cancel() method of the event class. Event classes are subclasses of the AdfBaseEvent class.

You listen to client events by using the af:clientListener component to call a JavaScript method in response to a client event. The af:clientListener component is used as a child of the ADF Faces component that generates the event.

Finally, note that in order to be able to cancel an event from propagating to the server, the event must be cancelable. You can determine whether an event is cancelable or not by calling the event isCancelable() method. This method returns true if event propagation can be canceled.

Example:

function customClientListener(event)
{
    // cancel event propagation to the server
    if (event.isCancelable()) {
        event.cancel();
    }

    // do client event processing
}


Context:

ADF Faces