After a connection was established between socket server and socket client, the latter can send messages to socket server anytime by using emit( ) method with “chat message” event and message object as arguments.
To receive message object from client, socket server need to define an event handler on “chat message” event.
<!--index.html-->
<!DOCTYPE html>
<html>
<head>
<title>Khmer Web Chat</title>
<link rel="stylesheet" href="/base.css" />
<link rel="stylesheet" href="/chat.css" />
<link href="/fonts/setup.css" rel="stylesheet" />
<link href="/logo.png" rel="icon" />
</head>
<body>
<section class="Chat region">
<div class="main">
<div class="title">
<input type="button" value="Leave chat" />
</div>
<div class="outer">
<div id="messages">Chat messages</div>
<form action="" onSubmit="submitHandler(event)">
<input type="text" id="chat-name"
required placeholder="Chat name" />
<input id="input" autocomplete="off" required
placeholder="Type your message here" />
<input type="submit" value="Send" />
</form>
</div>
</div>
<div class="sidebar">
<div class="title">All people</div>
<div class="content">Users</div>
</div>
</section>
<script src="/socket.io/socket.io.js"></script>
<script>
let socket = io();
function submitHandler(e){
e.preventDefault();
const chatName = document.getElementById('chat-name');
const input = document.getElementById('input');
const obj = {chatName: chatName.value, message: input.value};
if (input.value) {
socket.emit('chat message', obj);
input.value = '';
}
}
</script>
</body>
</html>
// index.js
// npm install express
// npm install socket.io
// npm install nodemon
const express = require('express');
const app = express();
const http = require('http');
const server = http.createServer(app);
const path = require('path');
const { Server } = require("socket.io");
const io = new Server(server);
const port = process.env.PORT || 3000;
app.use(express.static(path.join(__dirname, 'public')));
app.get('/', (req, res) => {
res.sendFile(`${__dirname}/index.html`);
});
io.on('connection', (socket) => {
console.log('a user connected');
socket.on('chat message', (obj) => {
console.log(`message: '${JSON.stringify(obj)}`);
});
});
server.listen(port, () => {
console.log(`listening on *${port}`);
});
