Package org.zkoss.zk.ui.util

Interface Composer<T extends Component>

All Known Implementing Classes:
GenericAutowireComposer, GenericComposer, GenericForwardComposer, MultiComposer, SelectorComposer
public interface Composer<T extends Component>
Represents a composer to initialize a component (or a component of tree) when ZK loader is composing a component. It is the controller in the MVC pattern, while the component is the view.

To initialize a component, you can implement this interface and then specify the class or an instance of it with the apply attribute as follows. 

<window apply="my.MyComposer"/>
<window apply="${a_composer}"/>

Then, ZK loader will

  1. Invoke ComposerExt.doBeforeCompose(org.zkoss.zk.ui.Page, org.zkoss.zk.ui.Component, org.zkoss.zk.ui.metainfo.ComponentInfo), if the composer also implements ComposerExt.
  2. Create the component (by use of UiFactory.newComponent(org.zkoss.zk.ui.Page, org.zkoss.zk.ui.Component, org.zkoss.zk.ui.metainfo.ComponentInfo, org.zkoss.zk.ui.Component), which creates and initializes the component accordingly).
  3. Invokes ComposerExt.doBeforeComposeChildren(T), if ComposerExt is also implemented.
  4. Composes all children, if any, of this component defined in the ZUML page.
  5. Invokes doAfterCompose(T) after all children are, if any, composed.
  6. Posts the onCreate event if necessary.

To intercept the lifecycle of the creation of a page, implement Initiator and specify the class with the init directive.

Note: AfterCompose has to be implemented as part of a component, while Composer is a controller used to initialize a component (that might or might not implement AfterCompose).

Alternatives: in most cases, you don't implement Composer directly. Rather, you can extend from one of the following skeletons.

SelectorComposer
It supports the autowiring based on Java annotation and a CSS3-based selector. If you don't know which one to use, use SelectorComposer.
GenericForwardComposer
It supports the autowiring based on naming convention. You don't need to specify annotations explicitly, but it is error-prone if it is used properly.
Since:
3.0.0
Author:
tomyeh
See Also:

  • Method Summary

    Modifier and Type
    Method
    Description
    void
    doAfterCompose(T comp)
    Invokes after ZK loader creates this component, initializes it and composes all its children, if any.

  • Method Details

    • doAfterCompose

      void doAfterCompose(T comp) throws Exception
      Invokes after ZK loader creates this component, initializes it and composes all its children, if any.
      Parameters:
      comp - the component has been composed
      Throws:
      Exception