ActiveRecord::Acts::Tree::ClassMethods

Specify this act if you want to model a tree structure by providing a parent association and a children association. This act requires that you have a foreign key column, which by default is called parent_id.

  class Category < ActiveRecord::Base
    acts_as_tree :order => "name"
  end

  Example:
  root
   \_ child1
        \_ subchild1
        \_ subchild2

  root      = Category.create("name" => "root")
  child1    = root.children.create("name" => "child1")
  subchild1 = child1.children.create("name" => "subchild1")

  root.parent   # => nil
  child1.parent # => root
  root.children # => [child1]
  root.children.first.children.first # => subchild1

In addition to the parent and children associations, the following instance methods are added to the class after specifying the act:

• siblings : Returns all the children of the parent, excluding the current node ([ subchild2 ] when called from subchild1)
• self_and_siblings : Returns all the children of the parent, including the current node ([ subchild1, subchild2 ] when called from subchild1)
• ancestors : Returns all the ancestors of the current node ([child1, root] when called from subchild2)
• root : Returns the root of the current node (root when called from subchild2)