From: ES <ruby-ml@...>
Date: 2005-10-07T02:42:28+09:00
Subject: Re: techniques for module to contribute to initialize() of its including classes

Robert Klemme wrote:
> itsme213 wrote:
> 
>>What are good design techniques for this e.g. if the module adds some
>>instance variables to its included class?
>>
>>module M
>>  def f
>>    @f
>>  end
>>  # how to initialize @f ?
>>end
>>
>>class A
>>  include M
>>end
>>Thanks.
> 
> 
> Do it like this and the module initialite will seamlessly integrate into
> the class inheritance chain:
> 
> module M
>   def initialize(*a,&b)
>     super
>     @f = 10
>   end
> end

This does not work directly if the class itself defines an #initialize
as it will take precedence over the module version.

> There have been discussions about this
> http://blade.nagaokaut.ac.jp/cgi-bin/scat.rb/ruby/ruby-talk/121611
> http://blade.nagaokaut.ac.jp/cgi-bin/scat.rb/ruby/ruby-talk/129974
> 
> Kind regards
> 
>     robert

E