5. Bonus Content

ActionMailer

Rails provides a simple way to create and send mails.

Let's create a Mailer by running this command:

foo@bar:~$ rails g mailer User company_created
      create  app/mailers/user_mailer.rb
      invoke  erb
      create    app/views/user_mailer
      invoke  test_unit
      create    test/mailers/user_mailer_test.rb
      create    test/mailers/previews/user_mailer_preview.rb

Go to the file app/mailers/user_mailer.rb and edit it like this:

class UserMailer < ApplicationMailer
  def company_created(company, user)
    @company = company

    mail to: user.email
  end
end

Now, let's edit the template (app/views/user_mailer/company_created.html.erb)

<h1>Congrats!</h1>

<p>
  Your company <%= @company.name %> has been created!
</p>

Now, add the gem letter_opener:

gem "letter_opener", group: :development

Run bundle install.

Then set the delivery method in config/environments/development.rb

config.action_mailer.delivery_method = :letter_opener
config.action_mailer.perform_deliveries = true

Model Callbacks

Rails provides different callbacks you can trigger after or before certain actions.

In order to trigger the previous email after company creation, we can add this to the Company model:

class Company < ApplicationRecord
  ...
  after_create :send_company_created_email

  private

  def send_company_created_email
    UserMailer.company_created(self, user).deliver_now
  end
  ...
end

Create a new company and let the magic begin!