On Thu, May 28, 2009 at 10:02 AM, Brian <[email protected]> wrote: > > On May 28, 2:59 am, Julian Leviston <[email protected]> wrote: >> Hi, >> >> > def self.included(base) >> > base.send :extend, ClassMethods >> > end >> >> > module ClassMethods >> > def my_method >> > end >> > end >> >> This is not a class method, is it? it's an instance method. a class >> method would be >> >> def self.my_method >> end >> >> > > I have all of 20 hours of Ruby experience now, so I'll probably screw > up this explanation. The whole include/extend thing is still very > confusing to me, but I'm having ActiveRecord::Base call include on my > module and attaching a callback so that I can do more. > ActiveRecord::Base is an instance of the Class class, so when the > callback uses extend, it is the ActiveRecord::Base instance itself > (and ActiveRecord::Base objects) that pick up the new my_method > instance method. My understanding is that Ruby then attaches this to > a metaclass for the ActiveRecord::Base instance, making it a singleton > method. And I think that's all class methods really are; singleton > methods on the metadata class for an instance of the Class class. So > through module trickery I have created a new class method. > > If I have this wrong, let me know. I don't like to write code that I > don't understand, so the sooner I wrap my head around the actual > mechanics of how this works, the better.
No, you have this quite right, and extending a class/module with a 'class methods' module inside another module using the included hook is the standard way to add class methods. -- Rick DeNatale Blog: http://talklikeaduck.denhaven2.com/ Twitter: http://twitter.com/RickDeNatale WWR: http://www.workingwithrails.com/person/9021-rick-denatale LinkedIn: http://www.linkedin.com/in/rickdenatale --~--~---------~--~----~------------~-------~--~----~ You received this message because you are subscribed to the Google Groups "Ruby on Rails: Talk" group. To post to this group, send email to [email protected] To unsubscribe from this group, send email to [email protected] For more options, visit this group at http://groups.google.com/group/rubyonrails-talk?hl=en -~----------~----~----~----~------~----~------~--~---
