A rake file for managing multiple large translation files

locales.rake

begin
  require 'ya2yaml'
rescue LoadError
  print "The locales tasks were not loaded, since ya2yaml gem is not present. Don't worry if this is a production machine, it is required for development only.\n"
else
  LOCALES_PATHS = ["#{Rails.root}/config/locales/", "#{Rails.root}/config/locales/activerecord/", "#{Rails.root}/config/locales/authlogic/", "#{Rails.root}/config/locales/notification_templates/"]

  MASTER_LOCALE = "en"
  IGNORE_FILES = %w(en.yml en-UK.yml)

  class Hash
    def extract_untranslated(hash)
      target = {}
      self.keys.each do |key|
        if self[key].is_a? Hash and hash[key]
          subtree = self[key].extract_untranslated(hash[key])
          target[key] = subtree unless subtree.empty?
          next
        end
        target[key] = self[key] unless hash[key] || self[key] == {}
      end
      target
    end
  end

  namespace :locales do
    $KCODE = 'UTF8'

    # Extract the untranslated hashes from translation files (all but en.yml) and put them in a new file.
    #
    task :extract do
      LOCALES_PATHS.each do |locale_path|
        Dir["#{locale_path}*.yml"].each do |file_name|
          master_file_name = "#{locale_path}#{MASTER_LOCALE}.yml"
          master = YAML::load_file master_file_name
          bare_file_name = File.basename(file_name)

          if IGNORE_FILES.include?(bare_file_name)
            puts "- skipping master file and files we maintain ourselves"
            next
          end
          language_code = File.basename(file_name, '.yml')

          new_locale_path = locale_path.gsub('locales', "newlocales/#{language_code}")

          slave = YAML::load_file(file_name)
          unless slave[language_code]
            puts "-> ERROR on #{File.basename(file_name)}: can't find key '#{language_code}'!"
            next
          end
          extract = master[MASTER_LOCALE].extract_untranslated(slave[language_code])

          if extract.empty?
            puts "- skipping #{File.basename(file_name)} (contained the same keys)"
          else
            final = { language_code => extract }
            Dir.mkdir(new_locale_path) unless File.exists?(new_locale_path)

            File.open(new_locale_path + bare_file_name, 'w') do |file|
              file.write final.ya2yaml.gsub(/\s+$/, '')
            end
            puts "+ build new file #{new_locale_path + bare_file_name} for translation company"
          end
        end
      end
    end

    # Merge the translated extracts back into the original translation files.
    #
    task :merge do
      LOCALES_PATHS.each do |locale_path|
        Dir["#{locale_path}*.yml"].each do |file_name|

          language_code = File.basename(file_name, '.yml')

          # the new translations...
          new_translations_file = file_name.gsub('locales', "newlocales/#{language_code}")

          unless File.exists?(new_translations_file)
            puts "- no new translations for #{language_code}"
            next
          end

          original_translations = YAML::load_file(file_name)
          new_translations = YAML::load_file(new_translations_file)

          merged = original_translations[language_code].deep_merge(new_translations[language_code])
          final = { language_code => merged }

          # write the merged translations to the original file
          File.open(file_name, 'w') do |file|
            file.write final.ya2yaml.gsub(/\s+$/, '')
          end

          # delete the new translations file
          File.delete(new_translations_file)
          puts "+ merged #{File.basename(file_name)} in original, deleted temp file."
        end
      end
    end
  end
end