How to exclude guest users from getting emailed Rails 4 Devise

Question

Just set up my first mailer on Rails 4. I have a welcome email sent to new users as soon as they sign up (create) for a new account using devise.

I also have devise set up so that if a current_user is not found, a guest user will be created. Unfortunately, this is interfering with the mailer. Every time a guest account is created, the mailer will send an email to a non-existing email.

I am having trouble figuring out how to exclude the guests from the mailer.

user.rb:

after_create :send_welcome_mail
def send_welcome_mail
  UserMailer.welcome_email(self).deliver
end

mailers/user_mailer.rb:

class UserMailer < ActionMailer::Base
  default from: "[email protected]"

  def welcome_email(user)
    @user = user
    mail(:to => user.email, :subject => "Welcome!")
  end

end

application_controller.rb (guest creation):

def current_or_guest_user
    if current_user
      if session[:guest_user_id] && session[:guest_user_id] != current_user.id
        logging_in
        guest_user(with_retry = false).try(:destroy)
        session[:guest_user_id] = nil
      end
      current_user
    else
      guest_user
    end
  end

  # find guest_user object associated with the current session,
  # creating one as needed
  def guest_user(with_retry = true)
    # Cache the value the first time it's gotten.
    @cached_guest_user ||= User.find(session[:guest_user_id] ||= create_guest_user.id)

  rescue ActiveRecord::RecordNotFound # if session[:guest_user_id] invalid
     session[:guest_user_id] = nil
     guest_user if with_retry
  end

  private

  # called (once) when the user logs in, insert any code your application needs
  # to hand off from guest_user to current_user.
  def logging_in
    # For example:
    # guest_comments = guest_user.comments.all
    # guest_comments.each do |comment|
      # comment.user_id = current_user.id
      # comment.save!
    # end
  end

  def create_guest_user
    u = User.create(:name => "guest", :email => "guest_#{Time.now.to_i}#{rand(100)}@example.com")
    u.save!(:validate => false)
    session[:guest_user_id] = u.id
    u
  end

I'm sure this is easy, but I am still new to rails and am a bit confused on the best way to go about this. Let me know if you need any other code.

Answer 1

def welcome_email(user)

  # The following line is unnecessary. Normally, you do
  # something like this when you want to make a variable
  # available to a view

  #@user = user

  # You can make the if more explicit by writing
  # if user.id == nil, but if will return false in
  # Ruby if a value doesn't exist (i.e. is nil)

  if user.id
    mail(:to => user.email, :subject => "Welcome!")
  end

end