多对多用户和组，但组有所有者 [英] Many-to-many Users and groups, but groups have owners

问题描述

我在尝试理解/解决这个问题时遇到了麻烦.我正在尝试创建一个允许这种关系的关系:

I'm having trouble trying to understand/wrap my brain around this. I'm trying to create a relationship that allows this:

• 用户可以属于多个组
• 组可以有很多用户
• 一个网上论坛的所有者是用户
• 组的所有权可以转让

我已经建立了多对多关系，但是我似乎不明白如何设置所有权功能.

I've got the many-to-many relationship set up, but I can't seem to understand how to set up the ownership functionality.

这是我到目前为止在模型中所拥有的:

here is what i have so far in my models:

    class Group < ActiveRecord::Base
      has_and_belongs_to_many :users
      attr_accessible :name, :description, :isPublic, :tag_list, :owner
    end

    class User < ActiveRecord::Base
      has_and_belongs_to_many :groups
      attr_accessible :name, :description, :owner_id
    end

任何帮助将不胜感激！

推荐答案

您可以通过以下几种方法进行设置:

You can set it up a couple of ways:

1)使用联接模型，并在联接模型上放置一个标志，以指定组成员是所有者.

1) Use a join model and place a flag on the join model that specifies that the group member is an owner.

class Group < ActiveRecord::Base
  has_many :memberships
  has_many :users, through: :memberships
  attr_accessible :name, :description, :isPublic, :tag_list, :owner
end

class Membership < ActiveRecord::Base
  belongs_to :group
  belongs_to :user

  #this table has a flag called owner and thus a method called owner?
end

class User < ActiveRecord::Base
  has_many :memberships
  has_many :groups, through: :memberships
  attr_accessible :name, :description, :owner_id
end

2)保留现有的HABTM并添加另一个联接模型以跟踪所有权.

2) Keep your existing HABTM and add another join model for tracking ownership.

class Group < ActiveRecord::Base
  has_and_belongs_to_many :users
  has_many :group_ownerships
  has_many :owners, through: :group_owernships, class_name: "User"
  attr_accessible :name, :description, :isPublic, :tag_list, :owner
end

class GroupOwnership < ActiveRecord::Base
  belongs_to :group
  belongs_to :user
end

class User < ActiveRecord::Base
  has_and_belongs_to_many :groups
  has_many :group_ownerships
  has_many :owned_groups, through: :group_owernships, class_name: "Group"
  attr_accessible :name, :description, :owner_id
end

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