has_many through polymorphic true

rubyonrails-talk
1

This would be cool to have in Rails.

class User < ActiveRecord::Base   has_many :roles end

class Role < ActiveRecord::Base   belongs_to :user   belongs_to :rolable, :polymorphic => true end

class Student < ActiveRecord::Base     has_one :role, :as => :rolable     has_one :user, :through => :rolable # * This is not possible yet in Rails (I think). end

class Teacher < ActiveRecord::Base     has_one :role, :as => :rolable     has_one :user, :through => :rolable # * This is not possible yet in Rails. end

Then be able to say:

@student.user # Instead of having to say @student.role.user

Or even better be able to say @student.email when `email` was a column of User but not Student.

2

And it would be cool to be able to say:

@user.student # if the role was present or give nil otherwise.

3

I believe that the @student.user case is possible, so long as you change the :through => :rolable, to :through => :role