I'm right now developing a taxonomy system and I was in need of a tree that would be stored at server with UI at client - I think quite common requirement, right? I've done it already before for various trees, e.g. my FileTreePanel.

I've been too lazy to write the same code again and again so I put all basic operations into extension: Ext.ux.tree.RemoteTreePanel. The extension doesn't change appearance or behavior of the standard Ext.tree.TreePanel too much but it implements the following logic:

1. User makes a change of the tree (create node, rename node, delete node, D&D node)
2. Request is sent to server to execute, save this change.
3.a) Update GUI on success
3.b) Revert GUI to previous state on failure + display error message delivered from server.

If you're interested see live demo at http://remotetree.extjs.eu

All your comments, bug reports or ideas for improvements are welcome.

Note: I cannot publish the backend of the example so it makes no sense to ask me for it. Of course, you are free to analyze what is sent to the server and what comes back and to implement your own server solution.