4 Specify this +acts_as+ extension if you want to model a tree structure by providing a parent association and a children
5 association. This requires that you have a foreign key column, which by default is called +parent_id+.
7 class Category < ActiveRecord::Base
8 acts_as_tree :order => "name"
17 root = Category.create("name" => "root")
18 child1 = root.children.create("name" => "child1")
19 subchild1 = child1.children.create("name" => "subchild1")
22 child1.parent # => root
23 root.children # => [child1]
24 root.children.first.children.first # => subchild1
26 Copyright (c) 2007 David Heinemeier Hansson, released under the MIT license