Example of polymorphic association using has_many, through, source.
Here post is polymorphic resource which belongs to the author [can be student, teacher]
# app/models/student.rb
class Student < ActiveRecord::Base
has_many :posts, :as => author
end
# app/models/teacher.rb
class Teacher < ActiveRecord::Base
has_many :posts, :as => author
end
# app/models/post.rb
class Post < ActiveRecord::Base
belongs to :author, :polymorphic => true
end
Has_many through association on polymorphic models
# app/models/student.rb
class Student < ActiveRecord::Base
belongs_to :division
has_many :posts, :as => author
end
# app/models/division.rb
class Division < ActiveRecord::Base
has_many :students
has_many :student_posts, :through => :students, :source => :posts
end
Examples
ruby script/console
div = Division.first
div.student_posts
