Rails - Apr 2006 - ActiveRecord Parent-Child relationship bug? config problem?

If i have a parent that has_many :children, and the child belongs_to 
:parent.  Then when I add a new child to the parent like so: 
parent.children << Child.new, then shouldn''t the child also have
a
reference to the parent?  but it doesn''t-- child.parent is nil-- 
what''s
going on here?  is this as it should be-- shouldn''t it have a reference
to the parent.  am i missing some config somehwere?

thanks for the help!
(couldn''t figure it out from the rdocs or the source-- not quite at
that
level yet)

-mrspeck

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Posted via http://www.ruby-forum.com/.

Hi mrspeck,

I''m surprised child.parent did not give you an error.

try....
@p = Parent.new
@c = Child.new
@p.children << @c
@c.parent #=> nil

but now do...

@p.save

and now...

@c.parent #=> #<Parent>

Until your child is saved @c.parent_id will be nil so your poor child
wont know where to look!

cheers
-h

On 4/12/06, ActiveRecord <not_a_valid_email@noemail.com>
wrote:
> If i have a parent that has_many :children, and the child belongs_to
> :parent.  Then when I add a new child to the parent like so:
> parent.children << Child.new, then shouldn''t the child also
have a
> reference to the parent?  but it doesn''t-- child.parent is nil-- 
what''s
> going on here?  is this as it should be-- shouldn''t it have a
reference
> to the parent.  am i missing some config somehwere?
>
> thanks for the help!
> (couldn''t figure it out from the rdocs or the source-- not quite
at that
> level yet)
>
> -mrspeck
>
> --
> Posted via http://www.ruby-forum.com/.
> _______________________________________________
> Rails mailing list
> Rails@lists.rubyonrails.org
> http://lists.rubyonrails.org/mailman/listinfo/rails
>

Hey Henry-- thanks for the reply!

I understand that @c.parent will produce nil until @p is saved, but I 
guess what I''m asking is if this is as it should be?

If you add a child to a parent, why wouldn''t the << method also
go ahead
and point the child to the parent? (assuming the child belongs_to the 
parent, and most defintely if the parent''s has_many
:dependent=>true)
Doesn''t it just make sense then?  I can''t think of a case
where you
wouldn''t want this behavior, can you?

-mrspeck


Henry Turner wrote:
> Hi mrspeck,
> 
> I''m surprised child.parent did not give you an error.
> 
> try....
> @p = Parent.new
> @c = Child.new
> @p.children << @c
> @c.parent #=> nil
> 
> but now do...
> 
> @p.save
> 
> and now...
> 
> @c.parent #=> #<Parent>
> 
> Until your child is saved @c.parent_id will be nil so your poor child
> wont know where to look!
> 
> cheers
> -h

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Posted via http://www.ruby-forum.com/.