Send confirmation email callback w/devise. Confirmable module with allow login without confirmation

confirmation_email.html.slim

p Welcome #{@user.email}!

p You can confirm your account email through the link below:

p
  = link_to 'Confirm my account', confirmation_url(@user, :confirmation_token => @token)

Sender.rb

def confirmation_email(user)
  @user = user
  @token = user.confirmation_token
  mail(to: @user.email, subject: 'Please confirm your account')
end

user.rb

after_create :send_confirmation_email

def send_confirmation_email
  Sender.confirmation_emai(self).deliver
end