Building a Real-Time Chat Application with Socket.io, Express, React.js, and Chakra UI (Vite Setup)

mkdir chat-app
cd chat-app

mkdir chat-backend
cd chat-backend
npm init -y

npm install express socket.io

chat-backend/
│
├── server.js
└── package.json

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: 'http://localhost:5173',
    methods: ['GET', 'POST']
  }
});

io.on('connection', (socket) => {
  console.log('A user connected:', socket.id);

  socket.on('sendMessage', (message) => {
    io.emit('receiveMessage', message);
  });

  socket.on('disconnect', () => {
    console.log('A user disconnected');
  });
});

server.listen(4000, () => {
  console.log('Server listening on port 4000');
});

npm create vite@latest

cd chat-frontend
npm install socket.io-client @chakra-ui/react @emotion/react @emotion/styled framer-motion

chat-frontend/
│
├── src/
│   ├── components/
│   │   └── ChatBox.jsx
│   ├── App.jsx
│   └── main.jsx
├── index.html
└── package.json

import { ChakraProvider, Box, Heading } from "@chakra-ui/react";
import ChatBox from "./components/ChatBox";

function App() {
  return (
    <ChakraProvider>
      <Box p={5}>
        <Heading as="h1" mb={6}>
          Real-Time Chat
        </Heading>
        <ChatBox />
      </Box>
    </ChakraProvider>
  );
}

export default App;

import React, { useState, useEffect } from "react";
import { Box, Input, Button, HStack, VStack, Text, Avatar } from "@chakra-ui/react";
import { io } from "socket.io-client";

const socket = io("http://localhost:4000");

const ChatBox = () => {
  const [messages, setMessages] = useState([]);
  const [input, setInput] = useState("");
  const [userId, setUserId] = useState(null);

  useEffect(() => {
    // Generate or get userId from session storage
    let storedUserId = sessionStorage.getItem("userId");
    if (!storedUserId) {
      storedUserId = Math.random().toString(36).substring(7);
      sessionStorage.setItem("userId", storedUserId);
    }
    setUserId(storedUserId);

    // Listen for messages
    socket.on("receiveMessage", (message) => {
      setMessages((prevMessages) => [...prevMessages, message]);
    });

    return () => {
      socket.off("receiveMessage");
    };
  }, []);

  const sendMessage = () => {
    if (input.trim()) {
      const message = {
        userId,
        text: input,
      };
      socket.emit("sendMessage", message);
    //   setMessages((prevMessages) => [...prevMessages, message]);
      setInput("");
    }
  };

  return (
    <VStack spacing={4} align="stretch">
      <Box h="400px" p={4} borderWidth={1} borderRadius="lg" overflowY="auto">
        {messages.map((msg, index) => (
          <HStack key={index} justify={msg.userId === userId ? "flex-start" : "flex-end"}>
            {msg.userId === userId && <Avatar name="Me" />}
            <Box
              bg={msg.userId === userId ? "blue.100" : "green.100"}
              p={3}
              borderRadius="lg"
              maxW="70%"
            >
              <Text>{msg.text}</Text>
            </Box>
            {msg.userId !== userId && <Avatar name="Other" />}
          </HStack>
        ))}
      </Box>

      <HStack>
        <Input
          value={input}
          onChange={(e) => setInput(e.target.value)}
          placeholder="Type a message"
        />
        <Button onClick={sendMessage} colorScheme="teal">
          Send
        </Button>
      </HStack>
    </VStack>
  );
};

export default ChatBox;

cd chat-backend
node server.js

cd chat-frontend
npm run dev