gistfile1.rb

ProductsController.class_eval do
  def show
    product_source = Product.find_by_permalink!(params[:id])
    @product = ProductDecorator.new(product_source)
    return unless @product

    if params[:option_values]
      option_values_ids = [
        params[:option_values][:cpu].to_i,
        params[:option_values][:screen].to_i
      ]
    end

    @variants = @product.find_variants(option_values_ids)
    @product_properties = ProductProperty.includes(:property).where(:product_id => @product.id)
    @selected_variant = @variants.detect { |v| v.available? }

    referer = request.env['HTTP_REFERER']

    if referer && referer.match(HTTP_REFERER_REGEXP)
      @taxon = Taxon.find_by_permalink($1)
    end
   
    respond_with(@product)
  end
end