ADF Tree : Row Disclosure Listener which expands below the disclosed node

I recently had the scenario where more than one level of a tree node had to be expanded on the disclosure of a particular tree node.

For example, say you have the below tree:

-A

-B

  - B1

  - B2

    - B2a

    - B2b

  - B3

-C

then, on the disclosure of tree node B you would want all the children (B1, B2, B3, B2a, B2b) of tree node B to be expanded.

I've done it as follow. I've added the following property to my ADF Tree:

rowDisclosureListener="#{treeBean.discloseTreeNodeChildren}" 

Then I implemented the referenced method in my "treeBean" backing bean. It assumes a tree binding called: "tree." See the listing below:

public void discloseTreeNodeChildren(RowDisclosureEvent event) {
    RowKeySet addedKeys = event.getAddedSet();
    Iterator addedIt = addedKeys.iterator();

    if(addedIt.hasNext()) {

        Object addedKey = addedIt.next();
        TreeModel treeModel = (TreeModel) this.tree.getValue();
        JUCtrlHierNodeBinding nodeBinding = (JUCtrlHierNodeBinding)

               treeModel.getRowData(addedKey);
        String isLeaf = (String) nodeBinding.getAttribute("isLeaf");       

          // you have to have a condition to break the series of disclosure events!!

        if(!(new Boolean(isLeaf))) {
            TreeUtility.expandAllNodes(nodeBinding, this.tree.getDisclosedRowKeys(), 0, 1);
            AdfFacesContext.getCurrentInstance().addPartialTarget(this.tree);
        }
    }
}

Now the utility method called: "expandAllNodes()" I've implemented as such:

protected static void expandAllNodes(JUCtrlHierNodeBinding nodeBinding, RowKeySet

          disclosedKeys) {   
    List<JUCtrlHierNodeBinding> childNodes = (List<JUCtrlHierNodeBinding>)

        nodeBinding.getChildren();     
    ArrayList newKeys = new ArrayList();
    if(childNodes != null) {
        for(JUCtrlHierNodeBinding node : childNodes) {           
            newKeys.add(node.getKeyPath());

            // recursive call to the method expandAllNodes()         
            expandAllNodes(node, disclosedKeys);
        }
    }
    disclosedKeys.addAll(newKeys);     
}
A handy addition to the utility method above is to add currentLevel and targetLevel integers in order to apply a boundary to the expansion of nodes. This gives the ability to only expand n levels below the disclosed node...comes in handy in those "big oak trees!!" :-)