How to properly extend Devise Recoverable?

Question

I want Recoverable module to send "invite" emails with reset password links for my users (the app is on invite only), I partially declare methods in initializer:

module Devise
  class Mailer
    def invite_new_user(record)
      devise_mail(record, :invitation_instructions)
    end
  end
end

module Devise
  module Models
    module Recoverable
      def send_invite_user_instructions!
        return unless status == User::STATUS_PENDING
        generate_reset_password_token!
        ::Devise.mailer.invite_new_user(self).deliver
      end
    end
  end
end

And recoverable is extended nicely, but it says that my mailer does not have invite_new_user method (rails console output):

1.9.2p290 :002 > user.send_invite_user_instructions! 
  User Load (1.4ms)  SELECT "users".* FROM "users" WHERE "users"."reset_password_token" = 'zMQK1CEXYupjNKpH8dph' LIMIT 1
   (0.3ms)  BEGIN
   (15.0ms)  UPDATE "users" SET "reset_password_token" = 'zMQK1CEXYupjNKpH8dph', "updated_at" = '2012-05-01 17:40:32.085256' WHERE "users"."id" = 59
   (4.5ms)  COMMIT
NoMethodError: undefined method `invite_new_user' for Devise::Mailer:Class

but calling has method in the same console session:

1.9.2p290 :003 > ::Devise.mailer.method_defined? 'invite_new_user'
 => true 

What am I missing?

Answer 1

Devise can be set-up for what you need:

1- Create a Mailer class in app/mailers/auth_mailer.rb file and make it inherit from Devise::Mailer

class AuthMailer < Devise::Mailer
  def invite_new_user(record)
    devise_mail(record, :invitation_instructions)
  end
end

2- Instruct Devise to use your class by editing config/initializers/devise.rb file and adding

config.mailer = 'AuthMailer'

3- (optional) If (and only if) you use a delay email sending such as SideKiq or DelayedJob you may need to eager load in development, or the delayed job may not find your AuthMailer class. In config/environments/development.rb

config.eager_load = true

4- I personally would define your send_invite_user_instructions! method in my User class instead of patching Devise class

---

Side note: I'm not a big fan or doing a partial declaration of a class in Rails initializer, because depending on how the gem is designed you can have trouble with autoload : There is a gem (Monologue) that reload objects during run time, without running the initializers, so the monkey patch works well on the first call, but not on the next calls.