org.zkoss.zkdemo.test2
Class VoidComposer

java.lang.Object
  org.zkoss.zkdemo.test2.VoidComposer

All Implemented Interfaces:

Composer, ComposerExt

public class VoidComposer
extends java.lang.Object
implements Composer, ComposerExt

A composer that denies the creation of a component.

Author:

tomyeh

Constructor Summary

VoidComposer()

Method Summary

void	doAfterCompose(Component comp) Invokes after ZK loader creates this component, initializes it and composes all its children, if any.
ComponentInfo	doBeforeCompose(Page page, Component parent, ComponentInfo compInfo) Invokes before composing a component.
void	doBeforeComposeChildren(Component comp) Invokes after the component is instantiated and initialized, but before composing any child.
boolean	doCatch(java.lang.Throwable ex) Called when an exception occurs when composing the component.
void	doFinally() Called after the component has been composed completely.

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Constructor Detail

VoidComposer

public VoidComposer()

Method Detail

doAfterCompose

public void doAfterCompose(Component comp)

Description copied from interface: Composer

Invokes after ZK loader creates this component, initializes it and composes all its children, if any.

Specified by:

doAfterCompose in interface Composer

Parameters:

comp - the component has been composed

doBeforeCompose

public ComponentInfo doBeforeCompose(Page page,
                                     Component parent,
                                     ComponentInfo compInfo)

Description copied from interface: ComposerExt

Invokes before composing a component. If you want to manipulate the specified component info, you can use ComponentInfo.duplicate() to make a copy and then modify it such that it won't affect the default behavior.

Specified by:

doBeforeCompose in interface ComposerExt

Parameters:

page - the page for composing this component.

parent - the parent component, or null if it is the root component.

compInfo - the component info used to instantiate the component.

Returns:

the component info used to instantiate the component. In most case, it shall return compInfo. If null is returned, the component won't be instantiated. In other words, it is ignored.

doBeforeComposeChildren

public void doBeforeComposeChildren(Component comp)
                             throws java.lang.Exception

Description copied from interface: ComposerExt

Invokes after the component is instantiated and initialized, but before composing any child.

Specified by:

doBeforeComposeChildren in interface ComposerExt

Parameters:

comp - the component being composed

Throws:

java.lang.Exception

doCatch

public boolean doCatch(java.lang.Throwable ex)
                throws java.lang.Exception

Description copied from interface: ComposerExt

Called when an exception occurs when composing the component.

If you don't want to handle the exception, simply returns false. boolean doCatch(Throwable ex) {return false;}

An exception thrown in this method is simply logged. It has no effect on the execution. If you want to ignore the exception, just return true.

Specified by:

doCatch in interface ComposerExt

Parameters:

ex - the exception being thrown

Returns:

whether to ignore the exception. If false is returned, the exception will be re-thrown. Note: once a composer's doCatch returns true, the exception will be ignored and it means doCatch of the following composers won't be called.

Throws:

java.lang.Exception

doFinally

public void doFinally()
               throws java.lang.Exception

Description copied from interface: ComposerExt

Called after the component has been composed completely. It is the last step of the composing.

Note: it is always called even if ComposerExt.doCatch(java.lang.Throwable), ComposerExt.doBeforeComposeChildren(org.zkoss.zk.ui.Component) or Composer.doAfterCompose(org.zkoss.zk.ui.Component) is not called (due to exceptions).

Note: it is called after the onCreate event is posted, but before the onCreate and any other events are handled.

An exception thrown in this method is simply logged. It has no effect on the execution.

Specified by:

doFinally in interface ComposerExt

Throws:

java.lang.Exception