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
• Git

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 create a multi-room chat server using Node.JS and Socket.IO.

This chat service will contain a main lobby where users sign on with a nickname and can communicate with each other. Users may also create chat rooms for other to join. The entire app should be displayed on a single webpage, listing the room you are in, all available rooms, and the users in the current room.

The single room chat server and client are provided here: Socket.IO

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)