ZK Developer's Reference/MVVM/Data Binding/Initialization

This article is out of date, please refer to zk-mvvm-book/8.0/data_binding/initialization for more up to date information.

We can initialize any component's attribute by initial binding: @init. It loads ViewModel's property once at the beginning then the property won't be synchronized by binder during user interaction. But EL evaluation's result we expect in initial binding annotation is different for attribute "viewModel" and "form".

@init at viewModel Attribute

The first place we usually use this annotation is to assign a ViewModel to a component in viewModel attribute. When using in viewModel attribute, we should specify the full-qualified class name in a string literal in @init.

<window apply="org.zkoss.bind.BindComposer" viewModel="@id('vm') @init('foo.MyViewModel')">
</window>

The composer will resolve the string 'foo.MyViewModel' and create a object of it.

@init at Component's Attribute

It's common to use it to initialize a component's attribute with a constant value or a ViewModel's proeprty. The binder loads it once and doesn't synchronize it afterward during following user interaction.

	<label value="@init(vm.message)"/>
		
	<label value="@init(123)"/>
	
	<checkbox checked="@init(true)"/>

@init at Form Binding

We can also use the initial binding on the form binding to fill in predefined value.

<div	form="@id('fx') @init(vm.defaultOrder) @load(vm.order) @save(vm.order, before='compute')">

</div>

We'll describe more advanced usage with @init in section ZK Developer's Reference/MVVM/DataBinding/Form Binding.

Version History

Version	Date	Content
6.0.0	February 2012	The MVVM was introduced.