Quickly do something in a locale then switch back

temp_locale_controller.rb

class ActionController::Base
  protected
  def do_using_temp_locale(temp_locale, &block)
    if I18n.available_locales.include?(temp_locale.to_sym)
      original_locale = I18n.locale
      I18n.locale = temp_locale
      return_value = yield
      I18n.locale = original_locale
    else
      return_value = yield
    end
    return_value
  end
end

Usage:
do_using_temp_locale('locale_code'){ # do these things }

Useful for things like sending an email in another language then returning to render a page in the original.