Module 6

Module 6 builds upon the JavaScript skills you learned in Module 5.

Reading

The following articles on the online class wiki textbook contain information that will help you complete the assignments.

• Node.JS
• Socket.IO
• Pong Game

Individual Assignments

Install Node.JS

Install Node.JS from Apt or Yum according to the instructions in the Node.JS guide.

Static File Server in Node.JS

The individual portion of Module 6 is short in order to give you enough time to complete the group portion.

1. Copy the example code from the Node.JS guide into a file called static_server.js or something of that nature. Save it on your EC2 instance (but not in a place that Apache can serve!).

   Ensure that you understand what the static file server script is doing… this might show up on a quiz!

2. Make a directory parallel to static_server.js named static.
3. Change "<STATIC DIRECTORY NAME>" on line 11 of the static fileserver example code to reflect the name of the directory you just made.
4. Save the following files in your static directory:
   • hello.txt, a text file containing "Hello World"
   • brookings.jpg, an image file you can download from here: http://classes.engineering.wustl.edu/cse330/content/brookings.jpg
   • college.html, an HTML document based on the Quick and Easy HTML Layout containing an image tag pointing to brookings.jpg
   • phpinfo.php, a PHP file containing the phpinfo command that generates a diagnostic page of the server:

   <?php   phpinfo();   ?>
   

5. Boot up your Node.JS static fileserver, and from your browser, load all four of the files you created in step 4.

   Which ones work and which ones don't? Why might this be the case?

Group Project

In the group portion of Module 6, you will be building a multiplayer, networked Pong game using Node.JS and Socket.IO. Your game must enable users to choose a nickname and play a game of Pong with others on your site without logging in (no need for a password or Open ID).

If you want to reminisce and play some Pong on the command line before building it in Node.JS, here is the command, assuming you have emacs installed:

$ emacs -q --no-splash -f pong

Press C-x C-c to exit emacs.

Instructions on how to begin your group portion can be found here: Pong Game

Grading

We will be grading the following aspects of your work. There are 80 points total.

1. Individual Portion (25 Points):
   • Node.JS is installed on your EC2 instance (5 points)
   • The hello.txt, brookings.jpg, and city.html files all load successfully (3 points each)
   • Visiting a file that does not exist inside the static directory results in a 404 (3 points)
   • You can explain to the TA why phpinfo.php behaves the way it does when loaded through Node.JS (3 points)
   • Using Git, push your node.js app to bitbucket and clone it on your ec2 instance (5 points)
2. Pong Game (45 Points):
   • Matching Pairs of Players (10 Points):
     • Players are able to specify a name for themselves (3 points)
     • Players are able to initiate a game on their own (4 points)
     • When a game is started, both players need to consent (3 points)
   • Gameplay (10 Points):
     • The Pong game works (3 points)
     • There is a pause between a player losing a round and the ball being launched for the next round (3 points)
     • Victory condition is enforced (e.g., the first player to score 10 points wins the game) (4 points)
   • Socket.IO Communications (15 Points):
     • A mapping of players to their opponents exists on the server side (without this, you can't complete any other parts of the Socket.IO section) (3 points)
     • Start Game and End Game is forwarded from one client to the other via Socket.IO (3 points)
     • Paddle Moving is forwarded from one client to the other via Socket.IO (3 points)
     • Ball Hitting and Missing Paddle is forwarded from one client to the other via Socket.IO (3 points)
     • Ball Launching is forwarded from one client to the other via Socket.IO (3 points)
   • Best Practices (5 Points):
     • Code is well formatted and easy to read (2 points)
     • There are no XSS vulnerabilities (3 points)
     • Extra Credit: Your client.js code passes JSHint, a JavaScript validator (+2 bonus points)
     • Extra Credit: Your app.js code passes JSHint, a JavaScript validator (+2 bonus points)
   • Usability (5 Points):
     • Finding friends on the Pong interface is easy and intuitive (4 points)
     • Site is visually appealing (1 point)
3. Creative Portion (10 Points)