ZK Developer's Reference/MVVM/Syntax/ViewModel/Parameters/@Default

This article is out of date, please refer to zk-mvvm-book/8.0/syntax/viewmodel/parameters/default for more up to date information.

Syntax

@Default("defaultValue")

Description

Target: A method's parameter (for initial and command methods)

Purpose: Assign a binding parameter's default value when it's null.

You give annotation element's value with a String, and ZK will cast to the corresponding type of the parameter. You can apply this annotation after other parameter related annotation e.g., @BindingParam. If a parameter retrieved by first annotation is null, it uses the default value specified in this annotation.

Example

Pass parameter from a zul

<button id="first" onClick="@command('cmd', arg2=100)" />
<button id="second" onClick="@command('cmd')" />

Example to assign default value

	@Command
	public void cmd(@Default("false") Boolean arg1, @BindingParam("arg2") @Default("3") Integer arg2){
		//...
	}

• According to above example, if we click first button, binder will pass 100 to arg2. If we click second button, arg2 will be 3.

Version History

Version	Date	Content
6.0.0	February 2012	The MVVM was introduced.