Harjutus 11: Vestlusruum serveri ja klientrakenduse vahel

Teeme uus kaust source/repos

installerida pakendid ja ws (WebSocket)

Teeme uus fail “index.html” ja “index.js”

index.js:

const http = require("http")
const fs = require("fs")
const ws = new require("ws")

const wss = new ws.Server({noServer: true});

function accept(req, res) {
    if (req.url === '/ws' && req.headers.toLowerCase() ==='/websocket' && req.headers.connection.match(/\bupdate\b/i)) {
        wss.handleUpdgrade(req, res.socket, Buffer.alloc(0), onSocketConnect);
    }
    else if (req.url === "/") {
        fs.createReadStream("./index.html").pipe(res);
    }
    else {
        res.writeHead(404);
        res.end()
    }

}


const clients = new Set()

function onSocketConnect(ws) {
    clients.add(ws);
    ws.on('message', function(message) {
        message = message.slice(0,50)
        for(let client of clients) {
            client.send(message)
        }
    })
    ws.on('close', function() {
        log('connection closed')
        clients.delete(ws);
    })
}


let log

if(!module["parent"]) {
    log = console.log
    http.createServer(accept).listen(8080)
} else {
    log = function() {};
    exports.accept = accept
}

index.html

<!doctype html>
<form name="publish">
    <input type="text" name="message" maxlength="50"/>
    <input type="submit" value="Send"/>
</form>
 
<div id="messages"></div>
 
<script>
    let url = location.host == 'localhost' ?
        'ws://localhost:8080/ws' : location.host == 'javascript.local' ?
            `ws://javascript.local/article/websocket/chat/ws` : // dev integration with local site
            `wss://javascript.info/article/websocket/chat/ws`; // prod integration with javascript.info
    //создаем объект с вебсокетом
    let socket = new WebSocket(url);
 
    // отправляем сообщение на форму
    document.forms.publish.onsubmit = function() {
        let outgoingMessage = this.message.value;
 
        socket.send(outgoingMessage);
        return false;
    };
 
    // обрабатываем входящие сообщения
    socket.onmessage = function(event) {
        let incomingMessage = event.data;
        showMessage(incomingMessage);
    };
    //если пользователь закрыт сокет, то пишем об этом в консоли
    socket.onclose = event => console.log(`Closed ${event.code}`);
 
    // показываем сообщения в div#messages
    function showMessage(message) {
        let messageElem = document.createElement('div');
        messageElem.textContent = message;
        document.getElementById('messages').prepend(messageElem);
    }
</script>

Ja kui sa teed localhost ja “node index.js” me saame vaata xˇ