From: Alan Chen <alan@...>
Date: 2002-07-08T03:46:21+09:00
Subject: Re: passing to objects at the bottom

On Sun, Jul 07, 2002 at 04:33:27PM +0900, Tom Sawyer wrote:
> hey i found the answer! i got a clue from david. thanks david.
> 
> the trick is to use a class variable in a module, along with a class
> method for setting it, and then include it in the "bottom" class.
> 
> module Prefix
>   @@prefix
>   def set_prefix(x)
>     @@prefix = x
>   end
> end
> 
> class Bottom
>   include Prefix
>   def initialize
>     puts @@prefix
>   end
> end
> 
> class Top
>   def initialize
>     Prefix.set_prefix('whatever')
>   end
> end
> 
> and bingo!
> 
> ~transami

That design looks a little ugly to me. For one, if you can't have more than
one tree with different prefixes with that design.  You're esentially using
an obfuscated global variable.  How about just passing prefix to the bottom
element at instantiation?

class Bottom
  def initialize(name)
  end
end

class Top
  def initialize
    @prefix = 'pro'

    @bottom_array = []
  end

  def add_bottom(name)
    @bottom_array << Bottom.new( "#{@prefix}_name" )
  end
end	
-- 
Alan Chen
Digikata LLC
http://digikata.com