From: ara.t.howard@...
Date: 2006-07-23T23:34:25+09:00
Subject: Re: Set an instance variable before and after initialize

On Sun, 23 Jul 2006, Martin Jansson wrote:

> If possible, I would like to set a instance variable in an object before and
> after its initialize method is executed.

let initialize help you do this then:


harp:~ > cat a.rb
module BeforeAfterInit
   module InstanceMethods
     def before_initialize *a, &b
     end
     def after_initialize *a, &b
     end
     def initialize *a, &b
       before_initialize *a, &b
       r = super
       after_initialize *a, &b
       r
     end
   end
   module ClassMethods
     def before &b
       define_method 'before_initialize', &b
     end
     def after &b
       define_method 'after_initialize', &b
     end
   end
   def self.included other
     other.module_eval{ include InstanceMethods }
     other.extend ClassMethods
     super
   end
end

class C
   include BeforeAfterInit

   before{ @a = 40 }
   after{ @b = 2 }

   def m() @a + @b end
end

p C.new.m



harp:~ > ruby a.rb
42


regards.

-a
-- 
suffering increases your inner strength.  also, the wishing for suffering
makes the suffering disappear.
- h.h. the 14th dali lama