foodsoft/lib/order_csv.rb

require 'csv'

class OrderCsv < RenderCSV

  def header
    [
      OrderArticle.human_attribute_name(:units_to_order),
      Article.human_attribute_name(:order_number),
      Article.human_attribute_name(:name),
      Article.human_attribute_name(:unit),
      ArticlePrice.human_attribute_name(:price),
      OrderArticle.human_attribute_name(:total_price)
    ]
  end

  def data
    @object.order_articles.ordered.includes([:article, :article_price]).all.map do |oa|
      yield [
              oa.units_to_order,
              oa.article.order_number,
              oa.article.name,
              oa.article.unit + (oa.price.unit_quantity > 1 ? " × #{oa.price.unit_quantity}" : ''),
              number_to_currency(oa.article.price * oa.article.unit_quantity),
              number_to_currency(oa.total_price)
            ]
    end
  end
end