Background email delivery in Ruby on Rails - Mini Project: Build & Apply

Background email delivery

📖 Scenario: You are building a simple Rails app that sends welcome emails to new users. To avoid slowing down the app, you want to send these emails in the background.

🎯 Goal: Set up a background job to send welcome emails asynchronously using Rails Active Job and Action Mailer.

📋 What You'll Learn

Create a User model with email attribute

Create a WelcomeMailer with a welcome_email method

Set up a background job to send the welcome email

Trigger the background job when a new user is created

💡 Why This Matters

🌍 Real World

Sending emails in the background is common in web apps to keep the user experience fast and responsive.

💼 Career

Understanding background jobs and mailers is essential for Rails developers working on user notifications and communications.

1

Create User model with email attribute

Create a Rails model called User with a string attribute email.

Ruby on Rails

# Create User model with email attribute
# Your code here

Need a hint?

Use rails generate model User email:string to create the model and migration.

2

Create WelcomeMailer with welcome_email method

Create a mailer class called WelcomeMailer with a method welcome_email(user) that sets @user and calls mail(to: @user.email, subject: 'Welcome!').

Ruby on Rails

class User < ApplicationRecord
  # email attribute is a string
end

# Create WelcomeMailer with welcome_email method
# Your code here

Need a hint?

Use rails generate mailer WelcomeMailer to create the mailer.

3

Create background job to send welcome email

Create a job class called WelcomeEmailJob with a perform(user_id) method that finds the user by user_id and calls WelcomeMailer.welcome_email(user).deliver_now.

Ruby on Rails

class User < ApplicationRecord
  # email attribute is a string
end

class WelcomeMailer < ApplicationMailer
  def welcome_email(user)
    @user = user
    mail(to: @user.email, subject: 'Welcome!')
  end
end

# Create WelcomeEmailJob with perform method
# Your code here

Need a hint?

Use rails generate job WelcomeEmail to create the job.

4

Trigger background job after user creation

Add an after_create callback in the User model that calls WelcomeEmailJob.perform_later(self.id) to send the welcome email in the background.

Ruby on Rails

class User < ApplicationRecord
  # email attribute is a string

  # Add after_create callback to trigger WelcomeEmailJob
  # Your code here
end

class WelcomeMailer < ApplicationMailer
  def welcome_email(user)
    @user = user
    mail(to: @user.email, subject: 'Welcome!')
  end
end

class WelcomeEmailJob < ApplicationJob
  queue_as :default

  def perform(user_id)
    user = User.find(user_id)
    WelcomeMailer.welcome_email(user).deliver_now
  end
end

Need a hint?

Use after_create :send_welcome_email and define a private method send_welcome_email that calls the job.