I have been searching high and low for a plugin that will allow this, and decided to combine a few tools, write a few helper methods and controller actions and roll my own.
You can find awesome_nested_set at:
(Thank's guys, it really lives up to it's name) - check their wiki for gotchas and cheat sheets
I hope this will help someone else out there having the same problem as I did.
Create an interface to drag and drop categories in a tree-like structure with sorting (using unordered lists)
This works best with a new set, as I have implemented this in a few existing sets and found that in one particular project, some of the sorting was not working.
Please see the example_app directory for a simple working demo. NOTE: The demo uses rails 2.3.8
see rails3 example (rails 3.0.3 ruby 1.8.7) using github.com/galetahub/awesome_nested_set (rails 3 version)
I will admit that this is not the most efficient way of handling this action, but it does work well, especially if you're not sorting a nested set frequently. I welcome any refactoring suggestions. Feel free to email me at firstname.lastname@example.org
Thank you to Chelsea for helping me iron out some stubborn code during a hack-meetup.
This project is small, but many should find it useful as it took me a week to work this out due to a lack of simple documentation and very little help provided on stackoverflow.