Mongoid多态关联导轨

Question

Work env: Rails 4.2 mongoid 5.1

Below are my models:

class Tag
  include Mongoid::Document
  include Mongoid::Timestamps

  field :name, type: String

  belongs_to :entity_tags, :polymorphic => true
end

class EntityTag
  include Mongoid::Document
  include Mongoid::Timestamps

  field :tag_id, type: String
  field :entity_id, type: String    // Entity could be Look or Article
  field :entity_type, type: String    // Entity could be Look or Article
  field :score, type: Float

end

class Look
  include Mongoid::Document
  include Mongoid::Timestamps

  has_many :tags, :as => :entity_tags
end

 class Article
   include Mongoid::Document
   include Mongoid::Timestamps

   has_many :tags, :as => :entity_tags
 end

We are trying to implement polymorphic functionality between Looks and Articles to Tags.

ie Let's say we have a Tag named "politics", and we would like to add the tag to an Article with the score '0.9' and to a Look with the score '0.6'. The Score should be saved at the EntityTags Model.

The problem: The first assign of the tag works, but then when I try to assign the same tag to another entity, it removes it and reassigns it from the first one to the latter.

The assignment looks like the following:

entity.tags << tag

Does anybody know the proper way to save associations and create the EntityTag Object with the correct polymorphism and assignment properly?

Thanks!

Answer 1

根据此链接中的以下答案，我设法实现了一个非优雅的工作解决方案