ActsAsList
This acts_as extension provides the capabilities for sorting and reordering a number of objects in a list. The class that has this specified needs to have a +position+ column defined as an integer on the mapped database table.
Install
Specify it in your Rails config.
config.gem 'ryanb-acts-as-list', :lib => 'acts_as_list', :source => 'http://gems.github.com'
Then install it.
rake gems:install
Example
class TodoList < ActiveRecord::Base
has_many :todo_items, :order => "position"
end
class TodoItem < ActiveRecord::Base
belongs_to :todo_list
acts_as_list :scope => :todo_list
end
todo_list.first.move_to_bottom
todo_list.last.move_higher
Copyright (c) 2007 David Heinemeier Hansson, released under the MIT license