From: Ron Fox <fox@...>
Date: 2008-02-22T19:45:05+09:00
Subject: Re: Reusing the existing code.

    That's >not< a beginner posting at all ;-) There's a well known maxim
in OO programming to prefer composition (what you are suggesting) to
inheritance.  The Suggestion by prizrak6 can also be used by
inheriting from one class and mixing in the second bits of functionality
as a module.
   The thing to always ask yourself  is what the relationship between
the new class and the existing classes is.

New class is an old class  -> inheritance
New class has an old class -> composition

Inheritance is very useful but often overused...where composition
is much more appropriate.

Without knowing more about the actual problem MohsinHijazee has, it's 
not possible to make detailed recommendations.

Ron Fox
Senior Physicist
National Superconducting Cyclotron Lab
Michigan State University
East Lansing, MI 48824-1321

Morel wrote:
> <prizrak6@yahoo.com> wrote:
> 
>> On 21 ???, 13:02, MohsinHijazee <mohsinhija...@gmail.com> wrote:
>>> Hi!
>>>    I have a new class which needs to reuse the code in two classes.
>>> But I can only derive it from one class. How should I go about it then?
>> Use mixins, by defining modules
> 
> Posting as a beginner, I wonder if something like this (inheriting from
> one class while incorporating an instance of the other) might work:
> 
> class SiblingClass < ParentClass1
> 
> def initialize
>   @reuseParent2 = ParentClass2.new()
> end
> 
> def method_missing(methodName,*args)
>   @reuseParent2.send(methodName,*args)
> end
> 
> end
>   
>