| Module | ActiveRecord::Acts::Tree::ClassMethods |
| In: |
lib/active_record/acts/tree.rb
|
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: