each

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each - java.lang.Object

The current item of the collection being iterated, when ZK evaluates an iterative element. An iterative element is an element with the forEach attribute.

<listbox width="100px">
	<listitem label="${each}" forEach="${contacts}" />
</listbox>

Nested forEach

To retrieve the index of the iteration, or the previous each object in nested forEach, you have to use another implicit object called forEachStatus.

<listbox forEach="${matrix}">
    <listitem label="${forEachStatus.previous.each.label}: ${each}" forEach=${each.items}/> <!-- nested-->
</listbox>

In Java

You could access the each object directly in zscript such as:

<window>
    <button label="${each}" forEach="apple, orange">
        <zscript>
   self.parent.appendChild(new Label("" + each));
        </zscript>
    </button>
</window>

The each object is actually stored in the parent component's attribute, so you could retrieve it in pure Java as follows.

public class Foo implements Composer {
    public void doAfterCompose(Component comp) throws Exception {
        Object each = comp.getParent().getAttribute("each"); //retrieve the each object
        ForEachStatus forEachStatus = (ForEachStatus)comp.getParent().getAttribute("forEachStatus");
        //...
    }
}

If the component is a root, you could retrieve them from page's attributes (Page.getAttribute(String)).

However, the value of each is reset after the XML element that forEach is associated has been evaluated. Thus, you cannot access it in an event listener, unless you store the value first. For more information, please refer to ZK Developer's Reference: Iterative Evaluation.

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Last Update : 2022/01/19

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