ZK Developer's Reference/MVVM/Syntax/ViewModel/@Init

This article is out of date, please refer to zk-mvvm-book/8.0/syntax/viewmodel/init for more up to date information.

Syntax

@Init

@Init(superclass=true)

Description

Target: method, class (since 6.0.1)

Purpose: Marker annotation to identify a initial method.

Binder calls the method with this annotation when initializing a ViewModel. In a ViewModel class, only one initial method is allowed at the most. If you set annotation element superclass to true, the ViewModel's parent class's initial method will be invoked first then child's, and this logic repeats on super class. If a class has no method with @Init, no method will be called (including the super class's).

For example, in a class hierarchy: A(has @init) <- B(has @init) <- C(no @init) <- D (has @init, superclass=true). D is the last child class.

• When binder initializes D as a view model, it will call D's initial method.
• When binder initializes C, no method will be called.
• When binder initializes B , it will call As' then B's.
• When binder initializes A, it will call A's.

We also can use parameter related annotation on initial method's parameters, please refer to subsections of ZK Developer's Reference/MVVM/Syntax/ViewModel/Parameters.

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Example

public class FooViewModel{
	@Init
	public void initFoo(){
		//initializing
	}
}

public class BarViewModel extends FooViewModel{
	@Init(superclass=true)
	public void initBar(){
		//initial method of super class FooViewModel will be called first.
	}
}

//since 6.0.1
@Init(superclass=true)
public class ChildViewModel extends BarViewModel{

}

Version History

Version	Date	Content
6.0.0	February 2012	The MVVM was introduced.