How can I send emails in Rails 3 using the recipient's locale?

Question

How can I send mails in a mailer using the recipient\'s locale. I have the preferred locale for each user in the database. Notice this is different from the current locale (I18n

Answer 1

This answer was a dirty hack that ignored I18n's with_locale method, which is in another answer. The original answer (which works but you shouldn't use it) is below.

Quick and dirty:

class SystemMailer < ActionMailer::Base
  def new_follower(user, follower)
    @follower = follower
    @user = user
    using_locale(@user.profile.locale){mail(:to=>@user.email)}
  end

  protected
  def using_locale(locale, &block)
    original_locale = I18n.locale
    I18n.locale = locale
    return_value = yield
    I18n.locale = original_locale
    return_value
  end
end