_changed? doesn't work for attribute aliases

+1

Thanks for writing this patch Rich. I've learnt a lot from reading through it and reproducing it - my patch wouldn't have been this clean.

Nice patch.

I think that should be documented somewhere. Since alias_attribute does not appear in the official API perhaps it would be enough to say something at the top of dirty.rb.

Well done! +1

Hey, nice work.

I don't quite follow why you have to use the metaclass when you're doing alias_method_chain though, shouldn't you be able to hook into the extended method in ClassMethods and just call alias_method_chain from there?

Thanks.

I do agree that extended is a much better place to put the alias_method_chain and I've made that change.

I did however maintain the metaclass approach because I've never seen a better way to amc class methods. I checked and other parts of rails are using the "class << ...end" approach which is what #metaclass is doing internally anyway. Just in case I remembered wrong, I did run through other approaches and they all resulted in errors.

I readily admit I could be mistaken here though. Feel free to correct me. I've never been thrilled with having to open up the metaclass to do this anyway.