Interactive digital whiteboard with real-time multiplayer cursor tracking, drawing shapes, and WebSockets sync.
Tick off requirements as you build to track real-time completion.
Follow this chronological guide to build the project from scratch.
Set up Express + Socket.io server broadcasting drawing events and maintaining room states.
const express = require('express');
const http = require('http');
const { Server } = require('socket.io');
const app = express();
const server = http.createServer(app);
const io = new Server(server, { cors: { origin: '*' } });
const rooms = new Map();
io.on('connection', (socket) => {
socket.on('join-room', (roomId, user) => {
socket.join(roomId);
socket.to(roomId).emit('user-joined', { socketId: socket.id, ...user });
});
socket.on('draw-element', ({ roomId, element }) => {
socket.to(roomId).emit('element-update', element);
});
socket.on('cursor-move', ({ roomId, position }) => {
socket.to(roomId).emit('peer-cursor', { socketId: socket.id, position });
});
});
server.listen(4000, () => console.log('Socket server running on port 4000'));Real issues students hit during development and how to troubleshoot them fast.
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