Rails4中的多态关联

Question

I'm following this tutorial http://blog.endpoint.com/2012/01/ruby-on-rails-rights-attributes.html to setup an authorization mechanism for my rails4 application.

I have created the data model but do not manage (from the console) to get the rights (via the all_rights method) of a user.

In the user model, how can the User object call "self.rights" as the rights are available through RightAssignment and not directly from User ?

My models:

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

Any idea ?

Answer 1

you can use :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