read_files.rb

require 'nokogiri'
require 'csv'

f_all = File.open("all.xml")
xml_all = Nokogiri::XML(f_all)

xml_all.search('food').each do |food|
  f_id = food.at("f_id").text
  puts "-- Opening #{f_id}.xml"

  f_food = File.open("#{f_id}.xml")
  xml_food = Nokogiri::XML(f_food)

  open("#{f_id}.csv", "w") do |csv|
    component_list = []

    csv << "f_id, f_ori_name, f_eng_name"

    xml_food.search('foodvalue').each do |fv|
      c_id = fv.search("c_id").text

      component_list.push(c_id)

      csv << ", \"c_#{c_id}\""      
    end

    csv << "\n"

    f_id = xml_food.at("f_id").text
    f_ori_name = xml_food.at("f_ori_name").text
    f_eng_name = xml_food.at("f_eng_name").text

    csv << "\"#{f_id}\", \"#{f_ori_name}\", \"#{f_eng_name}\""

    component_list.each do |component|
      csv << ", \""

      xml_food.search('foodvalue').each do |fv|
        if fv.at("c_id").text == component
          csv << fv.at("best_location").text
        end
      end

      csv << "\""
    end

    csv << "\n"

  end

  puts "-- Saving #{f_id}.csv"

  f_food.close

end

f_all.close