ruby-on-rails – 验证多态关联模型中的范围唯一性

对,所以我有一个多态关联,允许不同的对象类型被收藏.所以一个人可以喜欢一个产品,一个人,或者什么.我想做的是防止有人使用最喜爱的模型验证唯一性来重复收藏.

class Favorite < ActiveRecord::Base
 belongs_to :favoritable,:polymorphic => true
 belongs_to :user

 attr_accessible :user

 validates_presence_of :user
 validates :user_id,:uniqueness => { :scope => [:favoritable_type,:favoritable_id] }
end

验证似乎正在工作,但无论如何,当尝试复制条目时,仍然使用user_id创建一个新的“最爱”行.

有没有办法停止这个初始保存？

看来,Rails正在创建DB条目,然后使用favoritable_id和favoritable_type更新它,如下所示：

SQL (28.3ms)  INSERT INTO "favorites" ("created_at","favoritable_id","favoritable_type","updated_at","user_id") VALUES ($1,$2,$3,$4,$5) RETURNING "id"  [["created_at",Tue,14 Aug 2012 10:26:31 UTC +00:00],["favoritable_id",nil],["favoritable_type",["updated_at",["user_id",23]]
   (7.8ms)  COMMIT
   (0.1ms)  BEGIN
  Favorite Exists (0.3ms)  SELECT 1 AS one FROM "favorites" WHERE ("favorites"."user_id" = 23 AND "favorites"."id" != 123 AND "favorites"."favoritable_type" = 'Style' AND "favorites"."favoritable_id" = 29) LIMIT 1
   (0.2ms)  UPDATE "favorites" SET "favoritable_id" = 29,"favoritable_type" = 'Style',"updated_at" = '2012-08-14 10:26:31.943937' WHERE "favorites"."id" = 123
   (6.7ms)  COMMIT
   (0.1ms)  BEGIN

validates :user_id,:favoritable_id] }

validates :favoritable_type,:favoritable_id,:presence => true