ZK Developer's Reference/MVVM/Advanced/Wire Components

Although the design principle of MVVM pattern is that ViewModel should not have any reference to UI components, ZK still provides two ways to retrieve UI components in a ViewModel. However, we do not suggest this usage as it loses ViewModel an important advantage i.e. loose coupling with View. Notice that binder also manipulates UI components, so your operation to UI components may affect binder's work. Please be careful when using it.

One way is passing components as parameters in command binding which we have talked before. Another is to wire components by Selectors.wireComponents() . This way enables you to wire components with @Wire like what you do in a SelectorComposer.

Example to wire components in a ViewModel

public class SearchAutowireVM{

	//UI component
	@Wire("#msgPopup")
	Popup popup;
	@Wire("#msg")
	Label msg;

	@Init
	public void init(@ContextParam(ContextType.VIEW) Component view){
		Selectors.wireComponents(view, this, false);
	}

}

• Selectors.wireComponents()'s first parameters is Root View Component which can be retrieved by @ContextParam

Usage Changed in 6.0.2

The timing of BindComposer calling @Init method becomes earlier to handle more common situation. Hence, to wire components in a ViewModel, you should use @AfterCompose as follows:

Example to wire components in a ViewModel

public class SearchAutowireVM{

	//UI component
	@Wire("#msgPopup")
	Popup popup;
	@Wire("#msg")
	Label msg;

	@AfterCompose
	public void afterCompose(@ContextParam(ContextType.VIEW) Component view){
		Selectors.wireComponents(view, this, false);
	}

}

Version History

Version	Date	Content
6.0.0	February 2012	The MVVM was introduced.
6.0.2	July 2012	The @AfterCompose was introduced.