Building web apps with Rack

Now we're finally ready to write some code. We'll start building our view with HTML and JavaScript, working our way from the outside in. We're going to have to speed through this first step as it is impossible to capture the chaotic first steps of building a UI. The main point to keep in mind is that we're skipping the Ruby code that will power our app eventually.

We'll have a tiny mock web app in Ruby that serves our static HTML and JavaScript files, but that doesn't really count. By defining our UI first, we can figure out what our remaining code will need to do.

First, let's get our mock web app out of the way. All this does is serve static files, and we could have used Nginx or any other web server to achieve the same result. But we're going to use Rack (http://rack.github.io), a popular Ruby web server interface. It's worth learning more about Rack, as it's one of the most important Ruby libraries out there, and is the foundation of Sinatra, Rails, and other...