ADF Faces/Trinidad tree component’s state (expand/collapse by clicking on a node label)

This is a follow-up on a post “ADF Faces RC: Expanding an af:tree node by clicking onto its label” by Frank Nimphius.

The problem is to be able to expand/collapse a Tree node by clicking on it’s label. Frank’s solution is based on JavaScript. The solution bellow is a server side and based on a session backing bean.

Here’s a session bean to manage Tree state:

package electro;

import java.util.Iterator;
import java.util.List;
import javax.faces.event.ActionEvent;
import oracle.adf.view.faces.component.core.data.CoreTree;
import oracle.adf.view.faces.model.PathSet;

/**
 * Bean to manage tree state - open/close it's nodes.
 *
 * @author Viktoras Agejevas
 */
public class TreeState {

    private CoreTree tree;

    private Object clickedNodeRowKey;

    /**
     * Manage clicked tree node event
     *
     * @param actionEvent
     */
    public void clickTree(ActionEvent actionEvent) {
        PathSet pathSet = getTree().getTreeState();
        List<List> clickedNodePath = (List<List>) clickedNodeRowKey;
        Iterator i = getTree().getTreeState().getKeySet().iterator();

        boolean closedNode = false;

        while (i.hasNext()) {
            List openNodePath = (List) i.next();

            // close already open node
            if (openNodePath.equals(clickedNodeRowKey)) {
                pathSet.getKeySet().remove(clickedNodePath);
                closedNode = true;
            }
        }

        // open clicked node
        if (!closedNode) {
            pathSet.getKeySet().add(clickedNodePath);
        }
    }

    public void setTree(CoreTree tree) {
        this.tree = tree;
    }

    public CoreTree getTree() {
        return tree;
    }

    public void setClickedNodeRowKey(Object clickedNodeRowKey) {
        this.clickedNodeRowKey = clickedNodeRowKey;
    }

    public Object getClickedNodeRowKey() {
        return clickedNodeRowKey;
    }
}

And the Tree definition looks like this:

<af:tree value="#{bindings.RegionsView.treeModel}" var="node" binding="#{treeState.tree}">
    <f:facet name="nodeStamp">
        <af:commandLink text="#{node}" actionListener="#{treeState.clickTree}">
            <af:setActionListener from="#{treeState.tree.rowKey}" to="#{treeState.clickedNodeRowKey}"/>
        </af:commandLink>
    </f:facet>
</af:tree>

What we do here is bind tree component to a backing bean, on title click we pass current row and call clickTree method which expands/collapses tree node by current row value.

This solution has a little bit more code but I think it’s more bulletproof than the JavaScript one.