The <rich:changeExpandListener> represents an action listener method that is notified on an expand/collapse event on the node.

The <rich:changeExpandListener> is used as a nested tag with <rich:tree> and <rich:treeNode> components.

Attribute "type" defines the fully qualified Java class name for the listener. This class should implement org.richfaces.event.NodeExpandedListener interface.

The typical variant of using:

...

<rich:tree switchType="server" value="#{project.data}" var="item" nodeFace="#{item.type}">

    <rich:changeExpandListener type="demo.ListenerBean"/>

    ...

    <!-- Tree nodes --> 

    ...

</rich:tree>

...

Java bean source:

package demo;

import org.richfaces.event.NodeExpandedEvent;

public class ListenerBean implements org.richfaces.event.NodeExpandedListener{

    ... 

    public void processExpansion(NodeExpandedEvent arg0){

        //Custom Developer Code 

    }

    ...

}

...

Table of <rich:changeExpandListener> attributes.