ZK Developer's Guide

It's worth mentioning that requests to the same desktop are processed
sequentially, and requests to different desktops are processed in parallel.
That's important if you are using frames, and each frame is a desktop.
Phase: Request Processing
The ZK Asynchronous Update Engine updates the appropriate components.
Phase: Event Processing
This is the same as the event processing on creation of a page.
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Chapter 1
Phase: Rendering
ZK renders the affected components. The Client Engine updates the DOM tree on the
browser on the basis of the ZK responses.
Events in ZK—Listening and Processing
In the introduction to ZK with the "Hello World" example, we actually used a way
to register an event listener. We directly defined it as an attribute of a component in
the page:
.
The next way to define an event listener is in the component class. Here, we have the
first use of the use attribute of an element. When using the use attribute, the given
class should implement the base class of the control.
Now we can implement the event. In the example below, we implement the event
onOK. If the event contains necessary information for the processing it's possible to
give the method an argument org.zkoss.zk.ui.event.KeyEvent. However, the
implementation of the method is correct without the argument, too.
package sample;
import org.zkoss.zk.ui.event.KeyEvent;
import org.zkoss.zul.Window;
public class ExampleComponent extends Window
{