From: Gareth Adams <gareth.adams@...>
Date: 2007-12-12T02:58:48+09:00
Subject: Class variables per subclasses, defined in the superclass

Hi guys,

First the pastie, I got class_eval from #ruby-lang on freenode -
http://pastie.caboo.se/127003

I've commented out the Rails specific stuff so I'm sure this is a Ruby question.

What I'm trying to do is have a per-subclass variable created by a class method
on the super class (which is called from the subclass). Fun.

When I load in the file above I get

 -- Processor::Sponge.related_questions
 => {:surname=>1, :email=>1, :location=>1, :phone_number=>1, :forename=>1}
 -- Processor::CampaignMonitor.related_questions
 => {:surname=>1, :email=>1, :location=>1, :phone_number=>1, :forename=>1}
 -- Processor::Base.related_questions
 => {:surname=>1, :email=>1, :location=>1, :phone_number=>1, :forename=>1}

where the expected output is

 -- Processor::Sponge.related_questions
 => {:location=>1, :phone_number=>1}
 -- Processor::CampaignMonitor.related_questions
 => {:surname=>1, :email=>1, :forename=>1}
 -- Processor::Base.related_questions
 => {} # possibly nil, it's not too important as it shouldn't be called directly

I'll be the first to admit I don't really understand class variables, is what
I'm trying to do possible without having to add anything to the subclass?