Rails - Nov 2005 - Another CTI question

I''ve asked some CTI questions before and I have another one based on  
my migration progress.

These are two condensed tables (the actuals being bigger):

Content
+-------------+
| id          |
| title       |
| description |
| etc.....    |
+-------------+

ContentJob
+--------------+
| content_id   |
| location     |
| date_expired |
| etc.....     |
+--------------+

The above is legacy stuff and I can''t really change it right now as  
it''s live; my goal is to get Rails to use the existing infrastructure  
and then later make changes. My AR object is below:

class ContentJob < ActiveRecord::Base
   set_table_name    "content_job"
   set_primary_key   "content_id"
   has_one           :content, :dependent => true, :foreign_key =>
"id"
end

This works well. My tests allow me to find and update fine (working  
on delete right now). I have noticed tho if I create a ContentJob  
object via job = ContentJob.new , assign some values and then try to  
save it, I get an error saying that the primary / foreign key  
(content_id) does not have a value (or something similar). Which is  
fine as I understand why this is: a Content object does not exist yet.

So here''s my question:

If AR will handle the find and update logic correctly for an  
*existing* ContentJob/Content object but not for a new ContentJob  
object, could I then just create a save method in ContentJob that  
will be responsible for creating the dependent Content object and  
then hooking it up to the current ContentJob object? Like so:

ContentJob
----------

def save
   @content.save
   self.save
end

While this is not idea since it involves a few extra lines of code,  
it would be acceptable as I only have CTI on a few objects. I''m still  
working on all the finer points of Rails and Ruby, so my save method  
might not be completely correct and I''m assuming that when I have  
created a new ContentJob object that I automagically get a new  
Content object as well (not sure about this...). Anyway, does this  
make sense? I have to make the CTI stuff work and STI is not in the  
cards for me so hopefully the above approach will bridge this gap for  
now.

tia,

- jason