gistfile1.rb

class User < ActiveRecord::Base
  acts_as_group_member
  acts_as_named_group_member
end

class Manager < User
end

class GroupMembership < ActiveRecord::Base
  acts_as_group_membership
end

class Group < ActiveRecord::Base
  acts_as_group :members => [:users], :default_members => :users
end

# Migrations
class CreateGroups < ActiveRecord::Migration
  def change
    create_table :groups do |t|
      t.string :name
      t.string :type

      t.timestamps
    end
  end
end

class CreateGroupMemberships < ActiveRecord::Migration
  def change
    create_table :group_memberships do |t|
    t.string     :member_type
    t.integer    :member_id
    t.integer    :group_id
    t.string     :group_name
    t.string     :membership_type
  end
  end
end

class CreateUsers < ActiveRecord::Migration
  def change
    create_table :users do |t|
      t.string :name
      t.string :type

      t.timestamps
    end
  end
end