From: Tom Sawyer <transami@...>
Date: 2002-07-07T16:33:27+09:00
Subject: Re: passing to objects at the bottom

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


On Sat, 2002-07-06 at 17:11, Tom Sawyer wrote:
> i have a chain of objects such that one object contains another which
> contains another, and so on, down the line. the top object recieves a
> parameter which only the bottom most object in the chain is going to
> need. but how do i get it down there with out passing it through all the
> rest? and not using a global variable? for example:
> 
> class Top
>   def initialize(a)
>     Middle.new(a)
>   end
> end
> 
> class Middle
>   def initialize(a)
>     Bottom.new(a)
>   end
> end
> 
> class Bottom
>   def initialize(a)
>     puts a
>   end
> end
> 
> A.new("Thanks! I need that.")
> 
> how do i get a to Bottom without going through Middle, since Middle
> dosen't really need a. of course in my real program, i have about 4
> middles. does anyone have any better solutions to this problem?
> 
> -- 
> ~transami
> 
> "They that can give up essential liberty to obtain a little
>  temporary safety deserve neither liberty nor safety."
> 	-- Benjamin Franklin
> 
> 
-- 
~transami

"They that can give up essential liberty to obtain a little
 temporary safety deserve neither liberty nor safety."
	-- Benjamin Franklin