Rails - 视图上的模型关联

Question

我有这样的模型：

class Person
has_many :groups
has_many :group_memberships, :foreign_key => "member_id"
end

class Group_Membership
belongs_to :member, :class_name => 'Person'
belongs_to :group
end

class Group
belongs_to :person
has_many :group_memberships
has_many :members, :class_name => "Person", :through => "group_memberships", :foreign_key => "member_id"

一个人请求会员资格，创建一个status false的模型。 群组的所有者在他的person#show页面上可以看到谁申请了成员资格以及群组他参加了。由于 groups 和 group_memberships belongs_to 是 person，但 group_membership 也是 belongs_to 一个 group，我如何在 person#show 中创建一个视图，允许 person 查看谁请求了 会员资格 person 拥有哪些 group，以及 person 拥有哪些 group 成员资格？

##EDIT##

这里的status默认为false，因为person只会在< code>group 如果所有者编辑此状态并将其设置为true。

想法取自这个问题：关于 Rails 上的关联和模型的问题

Answer 1

这里有一些伪代码，我认为它们会让您走上您想要的道路： https://gist.github.com /981513

class Person
    has_many :groups
    has_many :group_memberships, :foreign_key => "member_id", :through => :groups

    scope :owned_groups, where(:is_owner => true).joins(:group_memberships) # gets all groups where this person is owner
end

class Group_Membership
    belongs_to :member, :class_name => 'Person'
    belongs_to :group

    # note that these attributes need to be defined
    # is_owner (boolean)
    # member_approved (boolean)

    scope :requested, :where(:member_approved => false)
end

class Group
    belongs_to :person
    has_many :group_memberships
    has_many :members, :class_name => "Person", :through => "group_memberships", :foreign_key => "member_id"
end

公平警告，我根本没有测试过它，而且我仍在学习新的 AR 模式:)

我认为你的 group_memberships 关系可能最适合作为 :through 关系，然后创建范围围绕关系可能具有的不同“状态”。您也可以查看 状态机 以获得一些帮助。

Answer 2

我是这样想的

class Person
  has_many :groups
  has_many :group_memberships, :foreign_key => "member_id"
  has_many :own_groups, :class_name => "Group", :through => "group_memberships", :foreign_key => "group_id"

end

class Group_Membership
  belongs_to :member, :class_name => 'Person'
  belongs_to :group
end

class Group
  belongs_to :person
  has_many :group_memberships
  has_many :asked_group_memberships, :class_name => 'Group_Membership', :conditions => ['status = ?', false]
  has_many :members, :class_name => "Person", :through => "group_memberships", :foreign_key => "member_id", :conditions => ['group_memberships.status = ?', true]
end