Today we're going to talk about two features of JSF 2.0's f:ajax tag: the event attribute and the listener attribute.

The use of both of these is really, really simple - so I'll just briefly cover the basics, and then launch directly into the sample code.

The "event" attribute of the ajax tag indicates which event to use to trigger the ajax request. There are any number of possible events allowed: You can use the standard browser DOM events (like click, change, keyup, etc. You can also use two special event values - action and valueChange. These two special values correspond to the same events that happen on the server side in JSF. On the client side, action is typically mapped to click, while valueChange is mapped to change or click, depending on the component.

The "listener" attribute of an ajax tag is a method that is called on the server side every time the ajax function happens on the client side. For instance, you could use this attribute to specify a server side function to call every time the user pressed a key - Handy, eh?

Read the original blog entry...