ticket_factory_3.rb

class TicketFactory
  def self.ticket_for opts
    class_for(opts[:vehicle_type]).new(opts)
  end

  # Method to auto generate class from a vehicle_type
  # e.g "Private car" => PrivateCarParkingTicket
  #     "Matatu" => MatatuParkingTicket
  def self.class_for vehicle_type
    prefix = vehicle_type.underscore.parameterize("_").camelize
    "#{prefix}ParkingTicket".constantize

    # If the class was not found
    rescue NameError
      ParkingTicket
    end
  end
end