rails polymorphic has_many: Menuable?

I want to have a Menu class which can point to either another submenu or and "endnode" like a Post or a Category class Menu < ActiveRecord::Base has_many :endnodes, :polymorphic => true belongs_to :parent_menu, :class_name => "Menu", :foreign_key => "parent_menu_id" has_many :sub_menus, :class_name => "Menu", :foreign_key => "parent_menu_id", :order => "sort ASC" end class Category