@Init"
| Line 18: | Line 18: | ||
</ref>. | </ref>. | ||
| − | 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. | + | 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 D as a view model, it will call D's initial method. | ||
* When binder initializes C, no method will be called. | * When binder initializes C, no method will be called. | ||
Revision as of 06:22, 10 July 2012
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. At most one initial method is allowed in a ViewModel class. If you set annotation element superclass to true, the ViewModel's parent class's ini 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)[1].
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.
- ↑ If you override parent class's initial method e.g. Parent.m1() <- Child.m1(). Because of Java's limitation, binder still call Child.m1(), and Child.m1() will be called twice. To avoid this, you should set superclass to false of Child.m1() and call super.m1() inside it.
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. |