From: "Ara.T.Howard" <Ara.T.Howard@...>
Date: 2005-09-15T14:01:34+09:00
Subject: Re: defining a method relative to a module's nesting

On Thu, 15 Sep 2005, Trans wrote:

>
>  module X
>    def self.included(mod)
>      define_method ... # define method from here
>    end
>  end
>
>  module N
>    # <- define method to this namespace (N)
>    module M
>      include X
>    end
>  end
>
> T.

one way:

   harp:~ > cat a.rb
   module X
     def self::included other
       class << other
         eval <<-code
           def foo
             42
           end
         code
       end
       super
     end
   end

   module N
     module M
       include X
     end
   end

   p N::M::foo

   harp:~ > ruby a.rb
   42


nicer way:

   harp:~ > cat a.rb
   module X
     module ClassMethods
       def foo
         42
       end
     end
     module InstanceMethods
       def foo
         'forty-two'
       end
     end
     def self::included other
       other.module_eval{
         extend ClassMethods
         include InstanceMethods
       }
     end
   end

   class N
     class M
       include X
     end
   end

   p N::M::foo

   nm = N::M::new
   p nm.foo

   harp:~ > ruby a.rb
   42
   "forty-two"


kind regards.

-a
-- 
===============================================================================
| email :: ara [dot] t [dot] howard [at] noaa [dot] gov
| phone :: 303.497.6469
| Your life dwells amoung the causes of death
| Like a lamp standing in a strong breeze.  --Nagarjuna
===============================================================================