Adventures of a Software Engineer

Month: May 2010

  • Expanding Rich tree nodes programmatically

    I have found two different methods for expanding nodes in Rich tree  from code, they both take  advantage of component binding and component state.

    Tree Setup

    Only thing to note here is the binding attribute that we setup in our backing bean.

    	protected org.richfaces.component.UITree sampleTreeBinding;

    for both solutions after we changed the sampleTree we need to update the binding with new value whitch is
    value="#{ourbean.sampleTree}" 

    // Make sure that we set the new TreeModel on current binding
sampleTreeBinding.setValue(sampleTree);

    Solution 1 : Expanding all nodes

    TreeState componentState = (TreeState) sampleTreeBinding.getComponentState();
try {
	componentState.expandAll(sampleTreeBinding);
} catch (IOException e) {
	e.printStackTrace();
}

    This will expand all levels of the nodes.

    Solution 2 : Expanding only nodes that meet our criteria

    try {
	final TreeState state = (TreeState) sampleTreeBinding.getComponentState();
	sampleTreeBinding.walk(FacesContext.getCurrentInstance(), new DataVisitor(){
		@SuppressWarnings("unchecked")
		public void process(FacesContext context, Object rowKey, Object argument)
		throws IOException {
			TreeRowKey row = (TreeRowKey)rowKey;
			if(row.depth() == 1){
				state.expandNode(sampleTreeBinding, (TreeRowKey)rowKey);
			}
		}
	});
}
catch (IOException e) {
	e.printStackTrace();
}


    Here we are only expanding nodes at depth 1 but it could be anything. Idea is that we are walking the tree
    
and checking if we are interested in the doing something with that node if so then we can modify it here.
    

    I hope this helps.