Polymorphic Timelines

polymorphic_timelines.rb

class Campaign < ActiveRecord::Base
  has_many :timelines, :through => :assignment
end

class Timeline < ActiveRecord::Base
  self.abstract_class = true
end

class Assignment < ActiveRecord::Base
  belongs_to :campaign
  belongs_to :timeline, :polymorphic => true
end

class FbAuth < Timeline
  has_many :campaigns, :through => :assignment, :as => :timeline
end

class TwAuth < Timeline
  has_many :campaigns, :through => :assignment, :as => :timeline
end

class FbPage < Timeline
  has_many :campaigns, :through => :assignment, :as => :timeline
end