What is the best practice to create has_one (always exist) model relationships when creating the parent model. eg: class User < ActiveRecord::Base has_one :balance end class Balance < ActiveRecord::Base belongs_to :user end A User always has a Balance I would like to create the Balance model when the User is saved. There is 3 (maybe more choices to accomplish this), which one is the best practice: 1. Create the Balance model and associate it to the User from the controller that is creating the User model. 2. Do it in the User model with after_create :create_balance 3. Do it in a UserObeserver: class UserObserver < ActiveRecord::Observer def after_create(user) balance = Balance.new(:amount => 0) balance = customer balance.save end end Thanks! If this has been covered before, sorry, but just not finding the right search terms to limit results.
on 2009-04-01 03:48
on 2009-04-01 04:44
On Tue, Mar 31, 2009 at 6:48 PM, Albert Wong < email@example.com> wrote: > belongs_to :user > controller that is creating the User model. > end > end > > Thanks! If this has been covered before, sorry, but just not finding > the right search terms to limit results. Albert, you should be able to do the following: class User < ActiveRecord::Base after_save :create_balance protected def create_balance balance = Balance.new( :amount => 0 ) # fill in any additional attributes balance.save! self.balance = balance # associate the balance to the user end end BTW, you can use an after_save filter to invoke the create_balance method when you save the user instance. Good luck, -Conrad
on 2009-04-01 07:48
Thanks Conrad... I think after_create is the better filter to use, otherwise the Balance is reset to 0 everytime there is an update to the User.
on 2009-04-01 14:48
Albert Wong wrote: > What is the best practice to create has_one (always exist) model > relationships when creating the parent model. In addition to the technical answers... Isn't the relation "always has one" really the relation "is part of"? Why all the fields are not in the same record?