i18n_active_record_missing_with_fallback.rb

#  Based on I18n::Backend::ActiveRecord::Missing, but provides some additional features:
#  - creates Translation object for each locale defined in I18n.available_locales
#  - looks up the translation using Simple backend and sets it as Translation#value
# 
#  Important! Remember to provide i18n.plural.keys in your YAML files. For example:
#
#    # en.yml
#    en:
#      i18n:
#        plural:
#          keys: [:zero, :one, :other]
#
#    # pl.yml
#    pl:
#      i18n:
#        plural:
#          keys: [:zero, :one, :few, :other]
module I18n
  module Backend
    class ActiveRecord
      module MissingWithFallback
        def fallback_backend
          @fallback_backend ||= I18n::Backend::Simple.new
        end
        
        def store_default_translations(locale, key, options = {})
          count, scope, default, separator = options.values_at(:count, *Base::RESERVED_KEYS)
          separator ||= I18n.default_separator

          keys = I18n.normalize_keys(locale, key, scope, separator)[1..-1]
          key = keys.join(separator || I18n.default_separator)

          unless ActiveRecord::Translation.locale(locale).lookup(key, separator).exists?
            interpolations = options.reject { |name, value| Base::RESERVED_KEYS.include?(name) }.keys
            keys = count ? I18n.t('i18n.plural.keys', :locale => locale).map { |k| [key, k].join(separator) } : [key]
            keys.each do |key|
              I18n.available_locales.each do |available_locale|
                store_default_translation(available_locale, key, interpolations)
              end
            end
          end
        end

        def store_default_translation(locale, key, interpolations)
          translation = ActiveRecord::Translation.new :locale => locale.to_s, :key => key
          translation.interpolations = interpolations
          translation.value = fallback_backend.send(:lookup, locale, key)
          translation.save
        end

        def translate(locale, key, options = {})
          super

          rescue I18n::MissingTranslationData => e
            self.store_default_translations(locale, key, options)

            raise e
        end
      end
    end
  end
end