Rails - Best-Practice: How to create dependent has_one relations

Question

Could you tell me whats the best practice to create has_one relations?

f.e. if i have a user model, and it must have a profile...

How could i accomplish that

Answer 1

Here's how I do it. Not sure how standard this is, but it works very well and its lazy in that it doesn't create extra overhead unless it's necessary to build the new association (I'm happy to be corrected on this):

def profile_with_auto_build
  build_profile unless profile_without_auto_build
  profile_without_auto_build
end

alias_method_chain :profile, :auto_build

This also means that the association is there as soon as you need it. I guess the alternative is to hook into after_initialize but this seems to add quite a bit of overhead as it's run every time an object is initialized and there may be times where you don't care to access the association. It seems like a waste to check for its existence.