I have the following ActiveRecord objects:
class Recipe < ActiveRecord::Base
has_many :ratings, :dependent => true
. . .
class Rating < ActiveRecord::Base
validates_uniqueness_of :created_by, :scope => :recipe_id
belongs_to :recipe, :counter_cache => true
. . .
The created_by field on Rating is implemented as a "magic" field
similar to this:
It is working fine.
The validates_uniqueness_of :created_by, :scope => :recipe_id isn't
working. I can easily go about adding multiple Ratings per Recipe for a
user. Maybe I'm missing something here, but what I want is to make sure
that a user can only add one Rating per Recipe. I'm guessing that the
created_by field is null when the validation runs, and then is
populated by the current user when the record is saved. Can anyone shed
some light on this and perhaps point me to a better solution?