Assignment: Web based Cross and Naught (Tic-Tac-Toe)
Complete with usage and test report via Stream site
In this assignment you will implement the game of cross and naught to be played between a web client and a server using TCP/IP sockets. The client can be any web browser, however you will have to write code to implement the server in any programming language, which supports raw sockets. You may use the server code in the tutorial exercises as a starting point.
The outline of the play is as follows. First the server starts and listens on some chosen port number. Then, client connects to the server at this port and requests for the game page (eg. game.html). The game page can be a simple html document consisting of the cross and naught board layout, a textbox for user input, and submit & reset buttons. You are free to design more interactive version of this page.
___1___|___2___|___3___
___4___ |___5___|___6___
7 | 8 | 9
The user claims a board position e.g. by typing a number between 1 and 9 on the keyboard. This move is sent to the server (using HTTP POST method), which updates its own representation of the board by marking this position. The server, as the second player in this game then uses random strategy to mark its own position. The revised board layout as part of the modified game page is then sent to the client.
In this manner the game continues and each side takes turn until either:
1. One of the players (either the user or the server) has claimed three board positions in a row, horizontally or vertically, or diagonally, in which case this player wins, or
2. The board is filled in and neither player has won, in which case the game is a draw.
The result of the game is displayed to the user when the game ends. The reset button simply allows the user to reinitialize the board to its initial state, and play the game again. Note that the user may choose to play on a position that has already been claimed. In this case, the player's move is ignored.
Let's think more about the architectural design. If you get your server to deal with the HTTP client request and handle the game logic, it is performing the role of an application server. Suppose if you want to implement more games like chess, you will end up overloading your web server with application logic.
A three-tiered architecture is a more scalable approach. Here the web server is oblivious to the game play and only focuses on serving standard HTTP requests. The backend application server implements the game logic and maintains state information (e.g. board position). In this way you can scale your web services by having a separate application server for each game. For the purpose of this assignment, the web server and application server can be running on the same host, and you can limit the game play to one client at a time.
