Rails%203%20In%20Action

318 CHAPTER 12 Sending email
Now that you have the user who created the ticket watching it, your CommentObserver
will have something to act on. Let’s see what happens when you run bin/cucumber
features/ticket_notifications.feature:
And I press "Create Comment"
uninitialized constant CommentObserver::Notifier (NameError)
This time, your feature is failing because it can’t find the constant Notifier, which is
actually going to be the class that you use to send out the notifications of new activity
to your users. To create this class, you’ll use Action Mailer.
12.1.4 Introducing Action Mailer
You need to define the Notifier mailer to send out ticket-update notifications using
your fresh-out-of-the-oven CommentObserver’s after_create method. You can do this
by running the mailer generator.
A mailer is a class defined for sending out emails. To define your mailer, you run
this command:
rails g mailer notifier
When running this command, you see this output:
create app/mailers/notifier.rb
invoke erb
create app/views/notifier
invoke rspec
create spec/mailers/notifier_spec.rb
The first thing the command generates is the Notifier class itself, defining it in a new
file at app/mailers/notifier.rb. This is done to keep the models and mailers separate.
In previous versions of Rails, mailers used to live in the app/models directory, which
led to clutter. By separating mailers out into their own folder, the codebase becomes
easier to manage. Inside this class, you define (as methods) your different notifications
that you’ll send out, beginning with the comment notification. You’ll get to that
in just a minute.
The second thing that is generated is the app/views/notifier directory, which is
used to store all the templates for your emails. The methods in the Notifier class will
correspond to each of the files in this directory.
The final thing that is generated is the spec/mailers/notifier_spec.rb, which you
won’t use because you’ve got your feature testing this notifier anyway.
In app/mailers/notifier.rb you see this code:
class Notifier < ActionMailer::Base
default from: "from@example.com"
end
ActionMailer::Base defines helpful methods such as the default one, which you can
use to send out your emails. 6 The default method here configures default options for
6 Action Mailer had a revamp with Rails 3, switching to be based on the new mail gem rather than the old
tmail gem. mail’s syntax is much nicer and won’t crash when it parses a spam email, unlike tmail.