<zk>
	<window apply="org.zkoss.bind.BindComposer"
		viewModel="@id('vm') @init('org.zkoss.test.testZK65.MyViewModel2')">


		<menubar id="mbar"
			children="@bind(vm.root.children) @template(empty each.children?'menuitem':'menu')">
			<template name="menu" var="node">
				<menu label="@bind(node.name)">
					<menupopup
						children="@bind(node.children) @template(empty each.children?'menuitem':'menu')" />
				</menu>
			</template>
			<template name="menuitem" var="node">
				<menuitem label="@bind(node.name)"
					onClick="@command('menuClicked',node=node)" />
			</template>
		</menubar>
		
		
		<hlayout children="@load(vm.path)">
			<template name="children">
				<label value="@load(each.name)"/>
				>>
			</template>
		</hlayout>
		
		<button label="update path" onClick="@command('updatePath')"/>
	</window>
</zk>

package org.zkoss.test.testZK65;

import java.util.ArrayList;
import java.util.List;

import org.zkoss.bind.annotation.BindingParam;
import org.zkoss.bind.annotation.Command;
import org.zkoss.bind.annotation.Init;
import org.zkoss.bind.annotation.NotifyChange;
import org.zkoss.test.testZK65.MyViewModel2.Node;

public class MyViewModel2 {

	private Node root;
	private Node selectedNode;
	
	private List<Node> path;

	@Init
	public void init() {
		root = new Node("Root");
		
		Node nodeA = new Node("Item A");
		Node nodeB = new Node("Item B");
		Node nodeC = new Node("Item C");
		
		
		root.appendChild(nodeA);
		root.appendChild(nodeB);
		root.appendChild(nodeC);
		
		
		Node nodeA1 = new Node("Item A1");
		Node nodeA2 = new Node("Item A2");
		
		nodeA.appendChild(nodeA1);
		nodeA.appendChild(nodeA2);
		
		
		Node nodeB1 = new Node("Item B1");
		Node nodeB2 = new Node("Item B2");
		
		nodeB.appendChild(nodeB1);
		nodeB.appendChild(nodeB2);
	}

	public Node getRoot() {
		System.out.println("-------------------load root--------------");
		return root;
	}

	public Node getSelectedNode() {
		return selectedNode;
	}
	
	public List<Node> getPath() {
		return path;
	}

	@Command
	@NotifyChange("path")
	public void menuClicked(@BindingParam("node")Node selectedNode ) {
		this.selectedNode = selectedNode;
		
		if (path == null)
			path = new ArrayList<Node>();
		else
			path.clear();
		
		Node curNode = selectedNode;
		
		while (curNode != null) {
			path.add(0, curNode);
			curNode = curNode.getParent();
		}
		
	}
	
	@Command
	@NotifyChange("path")
	public void updatePath() {
		path.add(new Node("new"));
	}

	public static class Node {
		private String name;
		private List<Node> children;
		private Node parent;

		public Node(String name) {
			super();
			this.name = name;
		}

		public String getName() {
			return name;
		}

		public List<Node> getChildren() {
			return children;
		}

		public Node getParent() {
			return parent;
		}

		public void appendChild(Node child) {
			if (children == null)
				children = new ArrayList<Node>();
			children.add(child);
			child.parent = this;
		}

		public void removeChild(Node child) {
			if (children == null)
				return;
			children.remove(child);
			child.parent = null;
		}

	}
}