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

The problem with the mentioned plugins are that they don't work in all situations, for example doing User.human_name or User.human_attribute_name(...) will not translate correctly. The following is the easiest and guaranteed method to work:

stick this somewhere (in initializers or a plugin):

  module I18nActionMailer
    def self.included(base)
      base.class_eval do
        include InstanceMethods
        alias_method_chain :create!, :locale
      end
    end

    module InstanceMethods
      def create_with_locale!(method_name, *parameters)
        original_locale = I18n.locale
        begin
          create_without_locale!(method_name, *parameters)
        ensure
          I18n.locale = original_locale
        end
      end
    end
  end

  ActionMailer::Base.send(:include, I18nActionMailer)

and then in your mailer class start your method by setting the desired locale, for example:

  def welcome(user)
    I18n.locale = user.locale
    # etc.
  end