The Game of Pig

This exam can be developed individually or in pairs.

Introduction

The game of Pig is a very simple jeopardy dice game in which two players race to reach 100 points. Each turn, a player repeatedly rolls a die until either a 1 is rolled or the player holds and scores the sum of the rolls (i.e. the turn total). At any time during a player’s turn, the player is faced with two decisions:

Roll: If the player rolls a:
- 1 : the player scores nothing and it becomes the opponent’s turn.
- 2 – 6 : the number is added to the player’s turn total and the player’s turn continues.
Hold: The turn total is added to the player’s score and it becomes the opponent’s turn.

Activity Description

Using Ruby and the Sinatra DSL, write a web application that allows playing the Game of Pig between multiple simultaneous pairs of users connected to the same network.

When a user connects to the web server for the first time, she must be allowed to choose between creating a new game or joining an existing one. Once two users are linked to the same game, it can start and proceed according to the rules described in the introduction section above.

Tips

Your web application can be designed as a single-page application (SPA) using AJAX and a client-side JavaScript framework (such as jQuery) or it can be comprised of multiple HTML pages. The latter option is probably the least complicated.
The information regarding the state of all current games can be stored inside a global object. There is no need to store it in a database or file.
You may assume that every access to the web server is done non-concurrently. This means you don't to have to worry about race conditions or synchronizing data access.
Given that some of the web pages will need to be refreshed automatically every few seconds (given that the state of the game will be updated during the turn of the other player), you can use the Refresh HTTP header in your responses. In Sinatra, this is accomplished like this:
```
get '/whatever' do
  # Return an array with: status, headers hash, and response body.
  [200, {"Refresh" => "5"}, erb(:whatever)]
end
```
This code refreshes the current requested resource after 5 seconds. Alternatively, you can use client-side JavaScript code to produce a similar effect.

Delivery and Assessment

Using the Online Assignment Delivery System (SETA), deliver a tarball file called exam3.tgz containing the directory with your full application. Additionally, the application will be personally assessed on Friday, November 15 during the class session.

Useful Links

Sintatra Web Site
Sinatra: Up and Running (Available through the University's Safari subscription).

Software Design and Architecture