Code Examples for my Blog Post: Create a Node.js Websocket Server in Five Minutes

_node-basic-websocket-server.md

Code Examples for my Blog Post: Create a Node.js Websocket Server in Five Minutes

The full Github repo can be found here: https://github.com/kevinchisholm/video-code-examples/tree/master/node/websocket-basic-server

Setup

• Clone this repo:

git clone git@github.com:kevinchisholm/video-code-examples.git

• Move into the project directory:

cd video-code-examples/node/websocket-basic-server/

(for example: cd ~/Desktop/video-code-examples/node/websocket-basic-server/)

• Install Dependencies:

npm install

Local Web Server Instructions

Start the local web server:

node index.js

Open the example web page:

http://localhost:3000/

example-1.js

"use strict";

const serverPort = 3000,
    http = require("http"),
    express = require("express"),
    app = express(),
    server = http.createServer(app),
    WebSocket = require("ws"),
    websocketServer = new WebSocket.Server({ server });

//when a websocket connection is established
websocketServer.on('connection', (webSocketClient) => {
    //send feedback to the incoming connection
    webSocketClient.send('{ "connection" : "ok"}');
    
    //when a message is received
    webSocketClient.on('message', (message) => {

        //for each websocket client
        websocketServer
        .clients
        .forEach( client => {
            //send the client the current message
            client.send(`{ "message" : ${message} }`);
        });
    });
});

//start the web server
server.listen(serverPort, () => {
    console.log(`Websocket server started on port ` + serverPort);
});

example-2.js

{
  "connection": "ok"
}

example-3.js

"use strict";
const serverPort = 3000, http = require("http"), express = require("express"), app = express(), server = http.createServer(app), WebSocket = require("ws"), websocketServer = new WebSocket.Server({ server });
websocketServer.on('connection', (webSocketClient) => {
    webSocketClient.send('{ "connection" : "ok"}');
    webSocketClient.on('message', (message) => { websocketServer.clients.forEach( client => { client.send(`{ "message" : ${message} }`) });
    });
});
server.listen(serverPort, () => {console.log(`Websocket server started on port ` + serverPort) });

package.json

{
  "name": "node-express-websockets-basic",
  "version": "1.0.0",
  "description": "Basic Websockets server using Node.js, Express.js and ws; a Node.js WebSocket library",
  "main": "index.js",
  "author": "Kevin Chisholm",
  "license": "ISC",
  "dependencies": {
    "express": "^4.16.2",
    "ws": "^4.0.0"
  }
}