Rails: includes with polymorphic association

Question

I read this interesting article about Using Polymorphism to Make a Better Activity Feed in Rails.

We end up with something like

class Activity < A         


        

Answer 1

I would suggest adding the polymorphic association to your Event and Guest models. polymorphic doc

class Event < ActiveRecord::Base
  has_many :guests
  has_many :subjects
  after_create :create_activities
end

class Image < ActiveRecord::Base
  has_many :tags
  has_many :subjects
  after_create :create_activities
end

and then try doing

Activity.includes(:subject => [:event, :guest]).order(created_at: :desc).limit(20)