Hangman (V2)

NodeJS web application created for Application Programming M30221.

Design

Aims

• Allow users to customize their games through a system of rules
• Limit amount of trust given to clients as much as possible without affecting server performance too much
• Minimise barriers to entry such as forced accounts etc

Assumptions

• Hosts will be able to kick players at their discretion thus some trust can be put in the client e.g. for turn timers

Basic flow

stateDiagram-v2
   [*] --> Homepage
   Homepage --> Lobby
   Lobby --> Homepage
   state Lobby {
      [*] --> Identification
      Identification --> Rules
      Rules --> Game
      Game --> Results
      Results --> Rules
   }

Loading

Practices

Variable naming

• HTML Classes: dash-case
• HTML ID's: snake_case
• JS: lowerCamelCase
• JS (Instantiable): UpperCamelCase
• SQL: snake_case

File Structure

Includes additional information for files/ folders of note.

hangman
│  index.js - Main server script that connects the different components.
│  package.json
│  .nvmrc
│  README.md
│  .gitignore
│
└──storage - Files related to the database
│  │  db.js - Script to provide wrapper functions to interface with the database and add support for async/ await.
│  │  schema.sql - Database initialisation code for the necessary tables
│
└──game - Files related to the logical components of the game
│  │  rules.js
│  │  rules.json - Contains JSON data for all rules
│  │  lobby.js
│  │  game.js
│  │  results.js
│  │  players.js
│  │  words.js - Wrapper for accessing lists contained in the wordlists directory through a dictionary.
│  └──wordlists - JSON files containing all possible words, separated by word length.
│  │  │  getWords.js - Script to filter + convert wordlist CSV into JSON files
│  │  │  ...
│
└──client - Static files for the client.
│  │  index.html
│  │  game.html
│  └──css
│  │  │  ...
│  │
│  └──js
│  │  │  ...
│
└──api - API router that interacts with the logical components.
   │  rest.js - Express router to handle most client interactions.
   │  websocket.js - Websocket server that checks client connections and informs clients of updates.

May not be fully exhaustive of all files included in the repository.

Running the server

1. Install NodeJS/ NPM
2. Open the code directory

cd ./hangman2

3. Install npm dependencies

npm i

4. Run the server

npm start

Optionally you may set the following environment variables in a .env file in the root directory or by including them in the run command.

PORT: The port to be used by the server (defaults to 8080)

Sources

I have used libraries or obtained data from the following sources:

• Express
• DotEnv
• Words:
  • hackerb9/gwordlist
  • Filtered with: Bad Words List