Rails Presenters example

presenter.rb

# Assume you also have the following "general case" presenters 
# app/presenters/cancellation_policy_presenter.rb
# app/presenters/daily_price_presenter.rb
# app/presenters/weekly_price_presenter.rb

# Now for some presenter fun..

# app/presenters/room_presenter.rb
class RoomPresenter
  # gives you access to RoomPresenter#cancellation_policy (see below)
  include RoomPresenters::CancellationPolicy
  
  # gives you access to RoomPresenter#daily_price and RoomPresenter#weekly_price (see below)
  include RoomPresenters::Prices
  
  def initialize(room)
    @room = room
    # + your awesome initialization codes here
  end
end

# app/presenters/room_presenters/cancellation_policy.rb
module RoomPresenters
  module CancellationPolicy
    def cancellation_policy
      @cancellation_policy ||= CancellationPolicyPresenter.new(@room).show
      # ..or modify the result of CancellationPolicyPresenter#show that applies only to rooms
    end
  end
end

# app/presenters/room_presenters/prices.rb
module RoomPresenters
  module Prices
    def daily_price
      @daily_price ||= DailyPricePresenter.new(@room).show
      # ..or modify the result of DailyPricePresenter#show that applies only to rooms
    end
    
    def weekly_price
      @weekly_price ||= WeeklyPricePresenter.new(@room).show
      # ..or modify the result of WeeklyPricePresenter#show that applies only to rooms
    end
  end
end