Tree component - can I declaratively hide the disclosure icon

Question

I have just started working with the tree component. Within the data model that I am working with, I've got branches that may or may not contain children. The child nodes are lazily fetched (which is good, for performance), but this results in the tree not knowing if children exist until the disclosure icon (the arrow) is clicked. This means that when the branch contains no children, the user has to click the arrow, and the arrow just disappears without anything on the tree changing. Because of the nature of the legacy data model that I am working with, I actually have an attribute that indicates if children exist (and I could have created a formula based attribute if no such indicator existed in the data model). I would like to be able to check this attribute (via EL or some other method) and suppress the disclosure icon if no children exist, but I have not found a way of doing it. Is this possible?

Answer 1

I was able to get this to work using the following disclosure listener:
  public void testDisclosureListener(RowDisclosureEvent rowDisclosureEvent) {
    Object rowKey = null;
    FacesCtrlHierNodeBinding rowData = null;
    RichTree tree = (RichTree)rowDisclosureEvent.getSource();
    RowKeySet rks = rowDisclosureEvent.getAddedSet();
    if (rks != null && rks.size() == 1) {
       rowKey = rks.iterator().next();
       tree.setRowKey(rowKey);
       rowData = (FacesCtrlHierNodeBinding)tree.getRowData();
       if ( rowData != null && rowData.getChildren() != null ) {
         // Iterate through the children of the expanded node and check if they have children
         for ( Object child : rowData.getChildren() ) {
           FacesCtrlHierNodeBinding childNode = (FacesCtrlHierNodeBinding)child;
           if ( childNode.getChildren() == null || childNode.getChildren().size() == 0 ) {
             // Child node is a leaf.  Add it to the disclosed rows, to that the ADF tree will not display a disclosure icon
             tree.getDisclosedRowKeys().add(childNode.getKeyPath());            
  }