Re: conditional association

AndyV
Mon, 28 Jan 2008 16:14:45 -0000

You might want to add

attr_accessor :profile

to your User and then have the subclasses populate @profile on the
user instance as necessary.  Off the top of my head you''d probably end
up with something like:

class User < Activerecord::Base
  attr_accessor :profile
ene

class Reader < User
  has_one :reader_profile
  def profile
    @profile ||= self.reader_profile
    @profile
  end
end

class Author < User
  has_one :author_profile
  def profile
    @profile ||= self.author_profile
    @profile
  end
end

By doing something like that your view could simply work with
@user.profile without worrying about how to load the data.  As for
rendering different templates, you should probably render only one,
and let that single template render the common components (User stuff)
and then farm out the custom stuff to partials.


HTH,
AndyV

On Jan 27, 1:38 pm, AD
<straightfl...-Re5JQEeQqe8AvxtiuMwx3w@public.gmane.org>
wrote:
> I think the STI for the user model makes the most sense.
> class User < Activerecord::Base
>
> class Reader < User
>  has_one :reader_profile
> end
>
> class Author < User
>  has_one :author_profile
> end
>
> end
>
>    Assuming I had a common controller called profile and wanted to display
> the appropriate profile is there an easier way then
>
>  def show
>    case current_user.type
>       when ''Reader''
>          @profile = ReaderProfile.find(:first, :conditions =>
["user_id > ?",current_user.id)
>          render :template => ''reader_profile''
>       when ''Author''
>          @profile = AuthorProfile.find(:first, :conditions =>
["user_id > ?",current_user.id)
>          render :template => ''author_profile''
>    end
> end
>
> On Jan 27, 2008 9:12 AM, Rick DeNatale
<rick.denat...-Re5JQEeQqe8AvxtiuMwx3w@public.gmane.org> wrote:
>
>
>
> > On 1/27/08, Gregory Seidman
<gsslist+...-dNXPQ6k9rNiG6BJUYyje5axOck334EZe@public.gmane.org> wrote:
>
> > > On Sun, Jan 27, 2008 at 10:29:06AM +0000, Frederick Cheung wrote:
> > > > On 27 Jan 2008, at 03:58, AD wrote:
> > > > >  i have an association as follows.  A user is of type
"author" or
> > > > > "reader".  In the user table is a column
called user_type_id that
> > > > > references a user_type table of 2 records, author,
reader.  What i
> > > > > am trying to do is the following:
>
> > > > >  Create an association such that a user has_one
:profile, but
> > > > > the :profile is either author_profile table or
reader_profile table
> > > > > (they have too many different attributes to make one
profile table)
> > > > > depending on the user type.  is there a way to specify
a conditional
> > > > > has_one in the user model that would allow access to
''user.profile''
> > > > > but know which model to reference ?  Either that or do
a conditional
> > > > > set_table_name depending on a variable ..
>
> > > > Perhaps a polymorphic association ? Or alternatively use
STI, and have
> > > > a base class User with the common functionality and both
Author and
> > > > Read inheriting from that. Then it''s easy, because
you just stick
> > > > has_one :author_profile in Author and has_one
:reader_profile in
> > Reader.
>
> > > Yep, I was going to suggest STI. This is exactly the sort of
situation
> > for
> > > which it is appropriate.
>
> > Well, it depends on how much the Author and Reader models have in
> > common, as to whether it makes sense to use STI, i.e. how many
> > attributes they have in common.
>
> > If it distorts reality too much to force them to use a single table,
> > then a polymorphic association is probably the better approach.
>
> > --
> > Rick DeNatale
>
> > My blog on Ruby
> >http://talklikeaduck.denhaven2.com/