From: Rick DeNatale <rick.denatale@...>
Date: 2008-02-17T23:18:59+09:00
Subject: Re: Problem with saving associated object

On Feb 16, 2008 4:59 PM, Jakub Kužma <adres.w@stopce.pl> wrote:
> Hi!
> I've following problem:
>
> class City < ActiveRecord::Base
>   has_one :marker
> end
>
> class Marker < ActiveRecord::Base
>   belongs_to :city
> end
>
> >> city = City.find(1)
> => #<City id: 1, name: "Warsaw", created_at: "2008-02-16 22:25:43",
> updated_at: "2008-02-16 22:26:53">
> >> city.marker.latitude = 60.0
> => 60.0
> >> city.save
> => true
> >> city.marker.latitude
> => 60.0
> >> city.reload
> => #<City id: 1, name: "Warsaw", created_at: "2008-02-16 22:25:43",
> updated_at: "2008-02-16 22:28:17">
> >> city.marker.latitude
> => 50.0
>
> AFAIR it worked in Rails 1.2. How to get behavior like above in Rails
> 2.0? Any advice would be appreciated :-).

You'll probably get a better response to this on the Rails forum, but.

I'm pretty sure that you're mistaken about how this worked on 1.2.
Looking at both AR 1.2 and 2.0 code, it looks like the only time
saving a record with a has_one/many relation saves the associated
record is when:

  1) Either the record with the has_x or the associated record is new, OR,
  2) if the id in the associated record doesn't match the id of the has_x record

So simply changing an attribute of the associated record wouldn't
cause the associated record to be updated.

-- 
Rick DeNatale

My blog on Ruby
http://talklikeaduck.denhaven2.com/