Rails%203%20In%20Action

340 CHAPTER 12 Sending email
12.4 Receiving emails
You’d now like to add a feature to Ticketee where users can reply to the email notifications
for a new comment on a ticket, and by replying create a new comment with their
text. Many other applications do this by having an email such as this:
== ADD YOUR REPLY ABOVE THIS LINE ==
Bob has just updated the "Due date" ticket for "TextMate 2"
Text above the “ADD YOUR REPLY ABOVE THIS LINE” will be parsed out and turned
into a new object. In Ticketee, this would be a comment.
In the previous section, you learned how you could connect to a Gmail account to
check to see if there was an email that had a subject beginning with “[ticketee].” You
can use the same method in order to check for replies to your emails too, but you
need to make one small modification.
To determine what ticket and project the reply is directed at, you need to tag the
emails in a certain way. The best way to do this is to add the tags to the email addresses
themselves, so that an email address with a tag looks like ticketee+tag@gmail.com,
where the +tag part of the email is ignored and the email arrives in ticketee
@gmail.com’s mailbox. For your emails, you’ll set a reply-to address such as ticketee
+61+23@gmail.com, where the first number is the project ID and the second number
is the ticket ID.
You’re not going to post comments straight from emails. You need to check to see
if the user has permission to view the project where the ticket is, which means that
they would be able to create a comment for that ticket too. If they’re unable to post a
comment to that ticket, you assume the user is trying to do something malicious and
just ignore their email.
To parse these emails, you’ll be using the receive method in an ActionMailer
class, which takes an email object and allows you to process it.
A quick summary: you’re going to use the gmail gem to check for emails in your
inbox that are replies to comment notifications and then parse them using Action
Mailer into new Comment objects. If a user is restricted from viewing a project, then
you’ll ignore their emails.
First, you want to check that the outgoing email contains the tag on the “from”
address, so that when a user replies to it you know what project and ticket they’re
replying to.
12.4.1 Setting a reply-to address
By having a different “from” address set on the outgoing email, you’ll be able to determine
what project and ticket the user’s reply comment should be created on. To
ensure that all outgoing emails from the comment_updated method in Notifier have
this set, you’re going to write a simple test.
Let’s open spec/mailers/notifier_spec.rb and change this whole file to what’s
shown in the following listing.