[RUBY] Email sending function with Action Mailer at the time of new registration

Overview

Use ActionMailer to send a welcome email when you register.

Premise

Implementation of login function using devise.

Installation procedure

1. Settings to use Action Mailer

The sender of the welcome email is Gmail. Description of how to set ActionMailer in config / environments / development.rb.

development.rb

Rails.application.configure do

#---Omission---#

　config.action_mailer.raise_delivery_errors = true
  config.action_mailer.delivery_method = :smtp
  config.action_mailer.smtp_settings = {
    port:                 587,
    address:              'smtp.gmail.com',
    domain:               'gmail.com',
    user_name:            'Source address',
    password:             'App password',
    authentication:       :plain,
    enable_starttls_auto: true
  }

For the app password, issue the first 16-digit password with 2-step authentication set, and enter it in the app password. I have referred to the following. -[Get password for Google mail application] (https://qiita.com/miriwo/items/833d4189140831c5d039) ・ [How to turn on Google two-step verification] (https://qiita.com/miriwo/items/0331e7241710fb4759fe)

2. Create Mailer class

$ rails g mailer UserNotice

3. Edit Mailer class

app/mailers/user_notice_mailer.rb

class UserNoticeMailer < ApplicationMailer
  def send_signup_email(user)
    @user = user
    mail to: @user.email, subject: "Membership registration is complete."
  end
end

4. Create email body

app/views/user_notice_mailer/send_signup_email.text.erb

Welcome<%= @user.name %>Mr

Thank you for registering for an account.

5. User model editing

app/models/user.rb

#---add to---#

  after_create :send_welcome_mail
 
  def send_welcome_mail
    UserNoticeMailer.send_signup_email(self).deliver
  end

You can use after_create to call a method to send an email after a new User has been created.

You should now receive a welcome email.