06-libraries/05-web/06-websocket/home.html

<!DOCTYPE html>
<html lang="en">
<head>
    <title>Websocket Sample</title>
    <script type="text/javascript">
        window.onload = function () {
            let socket;
            const msg = document.getElementById("msg");
            const messages = document.getElementById("messages");

            function appendMessage(item) {
                messages.appendChild(item);
                messages.scrollTop = messages.scrollHeight - messages.clientHeight;
            }

            document.getElementById("form").onsubmit = function () {
                if (!socket) {
                    return false;
                }

                if (!msg.value) {
                    return false;
                }

                socket.send(msg.value);
                msg.value = "";
                return false;
            };

            if (window["WebSocket"]) {
                socket = new WebSocket("ws://" + document.location.host + "/ws");

                socket.onclose = function (evt) {
                    const item = document.createElement("div");
                    item.innerHTML = "<i>Connection closed.</i>";
                    appendMessage(item);
                };

                socket.onmessage = function (evt) {
                    const messages = evt.data.split('\n');
                    for (let i = 0; i < messages.length; i++) {
                        const item = document.createElement("div");
                        item.innerText = messages[i];
                        appendMessage(item);
                    }
                };
            } else {
                const item = document.createElement("div");
                item.innerHTML = "<i>Your browser does not support WebSockets.</i>";
                appendMessage(item);
            }
        };
    </script>
    <style>
        html {
            overflow: hidden;
        }

        body {
            overflow: hidden;
            padding: 0;
            margin: 10% auto;
            width: 500px;
            height: 500px;
            background: #363636;
        }

        #messages {
            background: #eee;
            margin: 0;
            width: 500px;
            height: 400px;
            padding: 10px;
            overflow: auto;
            font-family: Verdana;
            font-size: 13px;
        }

        #msg {
            outline: none;
            border: none;
            border-top: 1px solid #ccc;
            width: 100%;
            padding: 10px;
        }
    </style>
</head>
<body>
    <div id="messages"></div>
    <form id="form">
        <input type="text" id="msg" placeholder="Type message..." autofocus />
    </form>
</body>
</html>