I have provided the source code of the ajax based drag drop tree in rubyonrails in one of my previous posts.
I found some of the people are getting problems to incorporate the code into their running applications so i am providing a sample rails application in which all the code for tree is already been [...]

Ajaxified Drag Drop Tree in RoR
CASE STUDY
I m providing a very generalized use case where the tree fits in a good position. Here it is…
Consider a model Item, a controller Items. Item model is using a fabulous acts_as_tree and we are going to put a seed for Item to grow it in an ajax tree [...]

Ajaxified tree comes with the following features
1.) Containing the ajax links for the tree items using link_to_remote
2.) Highlighting the selected node of the tree and other custom effects.
3.) Two way syncronization between the tree nodes and the currently displayed item on the web-page.
4.) Supports the tree architecture provided by the acts_as_tree.
5.) Clear and self traversing [...]