Hello, Rails!

4 Hello, Rails!

To begin with, let's get some text up on screen quickly. To do this, you need to get your Rails application server running.

4.1 Starting up the Web Server

You actually have a functional Rails application already. To see it, you need to start a web server on your development machine. You can do this by running the following in the blog directory:

$ bin/rails server

Compiling CoffeeScript to JavaScript requires a JavaScript runtime and the absence of a runtime will give you an execjs error. Usually Mac OS X and Windows come with a JavaScript runtime installed. Rails adds the therubyracer gem to the generated Gemfile in a commented line for new apps and you can uncomment if you need it. therubyrhino is the recommended runtime for JRuby users and is added by default to the Gemfile in apps generated under JRuby. You can investigate about all the supported runtimes at ExecJS.

This will fire up WEBrick, a web server distributed with Ruby by default. To see your application in action, open a browser window and navigate to http://localhost:3000. You should see the Rails default information page:

To stop the web server, hit Ctrl+C in the terminal window where it's running. To verify the server has stopped you should see your command prompt cursor again. For most UNIX-like systems including Mac OS X this will be a dollar sign $. In development mode, Rails does not generally require you to restart the server; changes you make in files will be automatically picked up by the server.

The "Welcome aboard" page is the smoke test for a new Rails application: it makes sure that you have your software configured correctly enough to serve a page. You can also click on the About your application's environment link to see a summary of your application's environment.