Forum: Ruby on Rails validate_presence_of :user or :user_id?

Hi all

I'm a bit confused whether it's better to check for the ID of a related
object or the related object itself?

validates_presence_of :user    # is this better?
validates_presence_of :user_id # or is this better?

What would you suggest? Thanks,
Josh

validates_presence_of :user_id
will test if there is a value for self.user_id regardless of whether
there is a valid user with that id  on the database.

If you're going to use :user_id then you should include
validates_associated :user to check the user is valid

validates_presence_of :user will check that the associated user is a
valid record.


On Apr 16, 2:09 pm, Joshua Muheim <rails-mailing-l...@andreas-s.net>

Thanks for your explanation. :-)

> validates_presence_of :user will check that the associated user is a
> valid record.

so if the user id is nil, then there is no error?

validates_presence_of :user_id only tests that there is a value for
user_id


with this method, user_id could be any integer, not necessarily a
valid user.

validates_presence_of :user will also check that the user is a valid
record on the database.

That clear it up?

Gavin wrote:
> validates_presence_of :user_id only tests that there is a value for
> user_id
> 
> 
> with this method, user_id could be any integer, not necessarily a
> valid user.
> 
> validates_presence_of :user will also check that the user is a valid
> record on the database.
> 
> That clear it up?

so validates_presence_of :user does the same like the combination of 
validates_presence_of :user_id and validates_associated :user... right? 
thanks for the explanation. :-)