ruby on rails - Devise custom mailer using Sendgrid -

i'd use sendgrid template send users welcome email when signup site. i've checked out: devise's how-to use customer mailer , done first few steps, however, i'm stuck on put confirmation_instructions method since need able put in custom information , substitution variables pass through. i'm using devise generated controller controllers/users/...

this have far:

custom class: models/devise_mailer.rb

class devisemailer < devise::mailer   helper :application   include devise::controllers::urlhelpers   default template_path: 'devise/mailer' end 

config/initializers/devise.rb

added: config.mailer = "devisemailer"

now here, i'm supposed below, don't know put that. need make custom controller? if so, how make sure new user registrations use method?:

def confirmation_instructions(record, token, opts={})   headers["custom-header"] = "bar"   super end 

am way off here?

put here:

class devisemailer < devise::mailer   helper :application   include devise::controllers::urlhelpers   default template_path: 'devise/mailer'    def self.confirmation_instructions(record, token, opts={})     new(:confirmation_instructions, record, token, opts)   end end 

(note changed method)

and call wherever want controller this:

current_user.send_confirmation_instructions