module Hooks::InheritableAttribute

Garfield.drinks #=> ["Becks", "Fireman's 4"]
Cat.drinks #=> ["Becks"]

and then, later

self.drinks << "Fireman's 4"
class Garfield < Cat

self.drinks = ["Becks"]
inheritable_attr :drinks
class Cat

Example:

chain. Note that you have to initialize the inheritable attribute.
attributes. This is especially helpful with arrays or hashes that are extended in the inheritance
Creates an inheritable attribute with accessors in the singleton class. Derived classes inherit the

def inheritable_attr(name)
  instance_eval %Q{
    def #{name}=(v)
      @#{name} = v
    end
    def #{name}
      return @#{name} unless superclass.respond_to?(:#{name}) and value = superclass.#{name}
      @#{name} ||= value.clone # only do this once.
    end
  }
end