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214 CHAPTER 9 File uploading
By providing Ticketee the functionality to attach files to the ticket, you provide the
project owners a useful context that will help them more easily understand what the
ticket creator means. Luckily, there’s a gem called Paperclip that allows you to implement
this feature easily.
Once you’re familiar with Paperclip, you’ll change your application to accept multiple
files attached to the same ticket using a JavaScript library called Prototype (which
comes with Rails) and some custom JavaScript code of your own. Because you’re using
JavaScript, you have to alter the way you test parts of your application. To test
JavaScript functionality, you’ll be using WebDriver, 1 which is a framework built for
automatic control of web browsers. WebDriver is especially useful because you can use
the same steps you use for standard Cucumber and Capybara tests and because Capybara
will take care of driving the browser. By running the tests inside the browser, you
ensure the JavaScript on the page will be executed, and then you can run the tests on
the results. Pretty handy!
Finally, you’ll see how you can restrict access to the files contained within the projects
of your application so that confidential information isn’t shared with people who
don’t have access to a particular project.
File uploading is also useful in other types of applications. Suppose you wrote a
Rails application for a book. You could upload the chapters to this application, and
then people could provide notes on those chapters. Another example is a photo gallery
application that allows you to upload images of your favorite cars for people to
vote on. File uploading has many different uses and is a cornerstone of many Rails
applications.
9.1 Attaching a file
You start off by letting users attach files when they begin creating a ticket. As
explained before, files attached to tickets can provide useful context as to what feature
a user is requesting or can point out a specific bug. A picture is worth a thousand
words, as they say. It doesn’t have to be an image; it can be any type of file. This kind of
context is key to solving tickets.
To provide this functionality, you must add a file-upload box to the new ticket
page, which allows users to select a file to upload. When the form is submitted, the file
is submitted along with it. You use the Paperclip gem to store the file inside your application’s
directory.
9.1.1 A feature featuring files
You first need to write a scenario to make sure the functionality works. This scenario
shows you how to deal with file uploads when creating a ticket. Users should be able to
create a ticket, select a file, and upload it. Then they should be able see this file, along
with the other ticket details, on the ticket’s page. They may choose to click the filename,
which would download the file. Let’s test all this by adding a scenario at the
1 There’s a great post explaining WebDriver on the Google Open Source blog: http://google-opensource
.blogspot.com/2009/05/introducing-webdriver.html.