Advanced Rails - Building Industrial-Strength Web Apps in Record Time

288 | Chapter 9: Incorporating and Extending Rails

Mailer classes and their email templates are defined just as they are in Rails:

class Mailer < ActionMailer::Base

def quota_exceeded_notification(user)

from "System Administrator <[email protected]>"

recipients name_and_email(user)

subject "Your account is over the quota"

body {:user => user}

end

private

# "John Smith <[email protected]>"

def name_and_email(user)

"#{user.full_name} <#{user.email}>"

end

end

The template follows the usual pattern, and is located under our template root, in
views/mailer/quota_exceeded_notification.erb:

Dear <%= @user.name %>,

Your account is over its storage quota. You are currently using

<%= human_size(user.storage_used) %>, and your limit is

<%= human_size(user.account.quota) %>.

Please reduce your usage within 5 days or we will reduce it for you.

Regards,

The Management

Now, this Mailer class can be used just as if it were inside a Rails application. We’ll
look at one possible application for this next.

Custom Rake tasks

Rake is best known in Rails for its purposes in testing. Rake is used to kick off Rails
tests, but also to perform administrative functionality (database maintenance and
migrations, managing temporary files and sessions, and the like). We can easily
extend Rake to handle any application-specific maintenance we need to do; in this
case, to find users who are over their quota and send them a nasty email. (For sim-
plicity, we will abstract away some of the details of finding those users.)

Here is a customRakefile that provides the email functionality:

require 'rake'

# Mailer setup commands from above

require 'mailer_config'

# ActiveRecord setup, not shown

require 'ar_users'