Tree: removing child nodes of a parent

I'm new to vaadin and I'm looking for a way to remove all the child nodes.  I tried

    @Override
    public void nodeCollapse(CollapseEvent event) {
        Object o=event.getItemId();
        
        Collection<?> col=tree.getChildren(o);
        col.clear();
    }
    
and received an UnsupportedOperationException.

I tried using an Iterator and removing one at a time and also received an error.  I looked through the forums and couldn't find the answer.  Anyone have a solution to this?

Thanks in advance.
 

Hi,

If you are using Java 8, you can try something like:

Collection<?> childrenIDs = tree.getChildren(o);
childrenIDs.stream().forEach(tree::removeItem);

If not, maybe something like:

Object[] toRemove = childrenIDs.toArray();
int size = toRemove.length;

for (int i = 0; i < size; i++) {
    tree.removeItem(toRemove[i]);
}

Hope that helps!