AfterCompose vs Init ZK

Question

I'm working with Zk Framework. I know the existence of @AfterCompose and @Init annotations, but I don't know the differences and the order when I use it in a ViewModel.

Can someone explain the differences?

For example,

@AfterCompose
public void init(@ContextParam(ContextType.VIEW) Component view) {
    Selectors.wireComponents(view, this, false); // wire the components here
}

@Init
public void init() {
    //do more things
}

Thanks

Answer 1

The difference between @init and @AfterCompose is when they are executed but not what they will execute. These two methods work in a similar way to assign the variables in View Model and any other initialization tasks not dependent on component creation.

The ZUL Page Lifecycle is as follows:

1. Page initialization

2. Component creation

It first loads the properties of the Components assigned in ZUL

If any View Model assigned to the component using ViewModel attribute then it initilized by Binder and calls init method

If we mark some method as @init annotation then it will be called here.

When the component is created completely it calls AfterCompose

If we mark some method as @AfterCompose annotation then it will be called here.

3. Event Processing

4. Rendering

---

@init :

3. It loads the annotated method declared in ViewModel initially at the time of creation of the ViewModel before the components are created completely.
4. We can able to assign the variables that need to be initialised in ViewModel using init method.

@AfterCompose :

1. It loads the annotated method declared in ViewModel only after completion of the Component creation.
2. We can able to assign the variables that need to be initialised in ViewModel using AfterCompose method.

Note : Using AfterCompose over init is recommended. Since it is called after the component creation and View Model initialization.

Please refer the below links for better understanding !!

https://www.zkoss.org/wiki/ZK_Developer%27s_Guide/Appendix/Component_Life_cycle/Table_of_Sequence

http://books.zkoss.org/zk-mvvm-book/8.0/syntax/viewmodelinit.html

http://books.zkoss.org/zk-mvvm-book/8.0/syntax/aftercompose.html