Agile Web Development with Rails, Edition 5

14.1 Iteration I1: Email Notifications

Create a mailer

rails generate mailer Order received shipped

      create  app/mailers/order_mailer.rb

      invoke  erb

      create    app/views/order_mailer

      create    app/views/order_mailer/received.text.erb

      create    app/views/order_mailer/received.html.erb

      create    app/views/order_mailer/shipped.text.erb

      create    app/views/order_mailer/shipped.html.erb

      invoke  test_unit

      create    test/mailers/order_mailer_test.rb

      create    test/mailers/previews/order_mailer_preview.rb

Edit development configuration

edit config/environments/development.rb

Rails.application.configure do

  # Settings specified here will take precedence over those in config/application.rb.

  # In the development environment your application's code is reloaded on

  # every request. This slows down response time but is perfect for development

  # since you don't have to restart the web server when you make code changes.

  config.cache_classes = false

  # Do not eager load code on boot.

  config.eager_load = false

  # Show full error reports.

  config.consider_all_requests_local = true

  # Enable/disable caching. By default caching is disabled.

  # Run rails dev:cache to toggle caching.

  if Rails.root.join('tmp/caching-dev.txt').exist?

    config.action_controller.perform_caching = true

    config.cache_store = :memory_store

    config.public_file_server.headers = {

      'Cache-Control' => "public, max-age=#{2.days.to_i}"

  else

    config.action_controller.perform_caching = false

    config.cache_store = :null_store

end

  # Store uploaded files on the local file system (see config/storage.yml for options)

  config.active_storage.service = :local

  # Don't care if the mailer can't send.

  config.action_mailer.raise_delivery_errors = false

  # Don't actually send emails

  config.action_mailer.delivery_method = :test

  # Alternate configuration example, using gmail:

  #   config.action_mailer.delivery_method = :smtp

  #   config.action_mailer.smtp_settings = {

  #     address:        "smtp.gmail.com",

  #     port:           587,

  #     domain:         "domain.of.sender.net",

  #     authentication: "plain",

  #     user_name:      "dave",

  #     password:       "secret",

  #     enable_starttls_auto: true

  #   }

  config.action_mailer.perform_caching = false

  # Print deprecation notices to the Rails logger.

  config.active_support.deprecation = :log

  # Raise an error on page load if there are pending migrations.

  config.active_record.migration_error = :page_load

  # Debug mode disables concatenation and preprocessing of assets.

  # This option may cause significant delays in view rendering with a large

  # number of complex assets.

  config.assets.debug = true

  # Suppress logger output for asset requests.

  config.assets.quiet = true

  # Raises error for missing translations

  # config.action_view.raise_on_missing_translations = true

  # Use an evented file watcher to asynchronously detect changes in source code,

  # routes, locales, etc. This feature depends on the listen gem.

  # config.file_watcher = ActiveSupport::EventedFileUpdateChecker

end

Tailor the from address

edit app/mailers/order_mailer.rb

class OrderMailer < ApplicationMailer

  default from: 'Sam Ruby <depot@example.com>'

  # Subject can be set in your I18n file at config/locales/en.yml

  # with the following lookup:

  #   en.order_mailer.received.subject

  def received

    @greeting = "Hi"

    mail to: "to@example.org"

end

  # Subject can be set in your I18n file at config/locales/en.yml

  # with the following lookup:

  #   en.order_mailer.shipped.subject

  def shipped

    @greeting = "Hi"

    mail to: "to@example.org"

end

end

Tailor the confirm receipt email

rm app/views/order*/received.html.erb

edit app/views/order_mailer/received.text.erb

Dear <%= @order.name %>

Thank you for your recent order from The Pragmatic Store.

You ordered the following items:

<%= render @order.line_items -%>

We'll send you a separate e-mail when your order ships.

Text partial for the line items

edit app/views/line_items/_line_item.text.erb

<%= sprintf("%2d x %s",

            line_item.quantity,

            truncate(line_item.product.title, length: 50)) %>

Get the order, sent the confirmation

edit app/mailers/order_mailer.rb

class OrderMailer < ApplicationMailer

  default from: 'Sam Ruby <depot@example.com>'

  # Subject can be set in your I18n file at config/locales/en.yml

  # with the following lookup:

  #   en.order_mailer.received.subject

  def received(order)

    @order = order

    mail to: order.email, subject: 'Pragmatic Store Order Confirmation'

end

  # Subject can be set in your I18n file at config/locales/en.yml

  # with the following lookup:

  #   en.order_mailer.shipped.subject

  def shipped(order)

    @order = order

    mail to: order.email, subject: 'Pragmatic Store Order Shipped'

end

end

Invoke mailer from the controller

edit app/controllers/orders_controller.rb

  def create

    @order = Order.new(order_params)

    @order.add_line_items_from_cart(@cart)

    respond_to do |format|

      if @order.save

        Cart.destroy(session[:cart_id])

        session[:cart_id] = nil

        session[:order_id] = @order.id

        OrderMailer.received(@order).deliver_later

        format.html { redirect_to store_index_url, notice:

          'Thank you for your order.' }

        format.json { render :show, status: :created,

          location: @order }

      else

        format.html { render :new }

        format.json { render json: @order.errors,

          status: :unprocessable_entity }

end

end

end

Tailor the confirm shipped email (this time in HTML)

rm app/views/order_mailer/shipped.text.erb

edit app/views/order_mailer/shipped.html.erb

<h3>Pragmatic Order Shipped</h3>

<p>

  This is just to let you know that we've shipped your recent order:

</p>

<table>

  <tr><th colspan="2">Qty</th><th>Description</th></tr>

<%= render @order.line_items -%>

</table>

Review HTML partial for the line items

edit app/views/line_items/_line_item.html.erb

<% if line_item == @current_item %>

<tr class="line-item-highlight">

<% else %>

<tr>

<% end %>

  <td class="quantity"><%= line_item.quantity %></td>

  <td><%= line_item.product.title %></td>

  <td class="price"><%= number_to_currency(line_item.total_price) %></td>

</tr>

Update the test case

edit test/mailers/order_mailer_test.rb

require 'test_helper'

class OrderMailerTest < ActionMailer::TestCase

  test "received" do

    mail = OrderMailer.received(orders(:one))

    assert_equal "Pragmatic Store Order Confirmation", mail.subject

    assert_equal ["dave@example.org"], mail.to

    assert_equal ["depot@example.com"], mail.from

    assert_match /1 x Programming Ruby 1.9/, mail.body.encoded

end

  test "shipped" do

    mail = OrderMailer.shipped(orders(:one))

    assert_equal "Pragmatic Store Order Shipped", mail.subject

    assert_equal ["dave@example.org"], mail.to

    assert_equal ["depot@example.com"], mail.from

    assert_match /<td[^>]*>1<\/td>\s*<td>Programming Ruby 1.9<\/td>/,

      mail.body.encoded

end

end

rails test test/mailers/order_mailer_test.rb

Run options: --seed 41481

# Running:

..

Finished in 0.729600s, 2.7412 runs/s, 13.7061 assertions/s.

2 runs, 10 assertions, 0 failures, 0 errors, 0 skips