From: Robert Klemme <bob.news@...>
Date: 2006-03-21T20:03:49+09:00
Subject: Re: Class (not instance) initializers

Bhrgunatha Deva wrote:
> Newbie question:
> 
> Is there an equivalent to a static constructor in ruby?
> something like:
> 
> class MyClass
>   # want this to run before any instances of MyClass are created
>   def class_initialize
>     self.some_complex_initialisation
>   end
> end
> 
> At the moment I'm using:
> class MyClass
>   def initialize
>     @@init = self.some_complex_initialisation if @@init.nil?
>   end
> end
> 
> I'd love to know if there is a more rubyesque way of doing this

Just place your code in the class body:

class MyClass
   @class_state = complex_calculation
end

Often one needs to inform a super class of a new child.  This can be 
done with #inherited:

class Base
   def self.inherited(cl)
     print Base, " was inherited by ", cl, "\n"
   end
end

 >> class Foo < Base
 >> end
Base was inherited by Foo
=> nil

Kind regards

	robert