Question

我无法弄清楚如何正确使用标题，所以让我解释一下。

我的班级喜欢：

class Like
  include Mongoid::Document
  belongs_to :likable, polymorphic: true
  belongs_to :user
end

class Submission
  include Mongoid::Document

  belongs_to :creator, class_name: 'User', inverse_of: :submissions
  has_many :likes, :as => :likable, :dependent => :destroy
end

然后导致问题的类：

class User
  include Mongoid::Document
  has_many :submissions, :dependent => :destroy

  has_many :liked_submissions, :as => :likable, :dependent => :destroy, class_name: 'Like'
  has_many :liked_comments, :as => :likable, :dependent => :destroy, class_name: 'Like'
end

现在，问题在于我无法弄清楚如何正确地同时拥有“喜欢的评论”。和＆＃39; likes_comments＆＃39;在用户类中。如上所述，当我尝试为提交创建类似内容时，我会收到错误：Ambiguous relations :liked_submissions, :liked_comments defined on User.。

我环顾四周，发现一个Github问题说这可能是不可能的，但我再也找不到这个问题了，我甚至不确定它是否与这个问题有关

这是否可行，如果没有，是否有任何建议可以绕过它？我也希望在BlogPost模型中使用喜欢，但如果这不起作用，我将不得不寻找另一种方式。

提前致谢。

Answer 1

我试过这个并使用mongoid版本4.0.2：

class Like
  include Mongoid::Document

  belongs_to :likable, polymorphic: true
  belongs_to :user, inverse_of: :user
end

class Submission
  include Mongoid::Document

  belongs_to :creator, class_name: 'User', inverse_of: :submissions
  has_many :likes, as: :likable, dependent: :destroy
end

class User
  include Mongoid::Document

  has_many :submissions, dependent: :destroy

  has_many :likes, as: :user
  has_many :liked_submissions, as: :likable, dependent: :destroy, class_name: 'Like'
  has_many :liked_comments, as: :likable, dependent: :destroy, class_name: 'Like'
end

class BlogPost
  include Mongoid::Document

  has_many :likes, as: :likable, dependent: :destroy
end

同样user.liked_submissions和user.liked_comments是相同的关系，所以它等同于声明这样的别名：

class User
  include Mongoid::Document

  has_many :submissions, dependent: :destroy

  has_many :likes, as: :user
  has_many :liked_submissions, as: :likable, dependent: :destroy, class_name: 'Like'

  alias :liked_comments :liked_submissions
end

Answer 2

在发现这个问题之后遇到了困难时期但是得到了很酷的解决方案

添加到您的Gemfile

gem'mongoid-multiple-polymorphic'

这就像一个魅力：

  class Resource

  has_one :icon, as: :assetable, class_name: 'Asset', dependent: :destroy, autosave: true
  has_one :preview, as: :assetable, class_name: 'Asset', dependent: :destroy, autosave: true

  end

一个模型中相同类型的多个多态关系--MongoID

2 个答案: