gistfile1.rbx

class CarController < ApplicationController
  def car
    layout = nil
    @scripts = []
    @stylesheets = []
    @car = Car.find(params[:id])

    layout = CarPresenter.present(@car, @stylesheets, @scripts)

    render :action => find_view, :layout => layout
  end
end

class CarPresenter
  CAR_VIEWS = {
    Toyota => { :layout => "two_column", :stylesheets => ['two_column_layout.css', 'two_column_theme.css'] },
    Hyundai => { :layout => "three_column", :stylesheets => ['three_column_layout.css', 'three_column_theme.css'], :scripts => ["discount.js"] }
    # etc.
  }

  def self.present(car, stylesheets, scripts)
    car_data = CAR_VIEWS[car.class]
    car_data[:stylesheets].each { |css| stylesheets << css }
    car_data[:scripts].each { |script| scrits << script }
    car_data[:layout]
  end
end