rails4中的多态关联

Question

我正在按照本教程 http://blog.endpoint.com/2012/01/ruby-on-rails-rights-attributes.html 为我的 rails4 应用程序设置授权机制。

我已经创建了数据模型，但没有管理（从控制台）获取用户的权限（通过 all_rights 方法）。

在用户模型中，用户对象如何调用“self.rights”，因为权限是通过 RightAssignment 而不是直接从 User 获得的？

我的模型：

class User < ActiveRecord::Base
  has_many :right_assignments, as: :subject
  has_and_belongs_to_many :groups
  has_and_belongs_to_many :roles

  def all_rights
    rights = [self.rights +
          self.groups.collect { |g| g.allowed_rights } +
          self.roles.collect { |r| r.rights }]
     rights = rights.flatten.uniq.collect { |r| r.action }
     rights
  end
end

class Group < ActiveRecord::Base
  has_many :right_assignments, as: :subject
  has_and_belongs_to_many :users

  def allowed_rights
    self.assignable_rights ? self.rights : []
  end
end

class Role < ActiveRecord::Base
  has_many :right_assignments, as: :subject
  has_and_belongs_to_many :users
end

class RightAssignment < ActiveRecord::Base
  belongs_to :right
  belongs_to :subject, polymorphic: true
end

class Right < ActiveRecord::Base
  has_many :right_assignments
end

有什么想法吗？

Answer 1

你可以使用:through

class User < ActiveRecord::Base
  has_many :right_assignments, as: :subject
  has_many :rights, :through => :right_assignments
  has_and_belongs_to_many :groups
  has_and_belongs_to_many :roles