web_toys/14_hello_mqtt.html at main · ervenus-dott/web_toys · GitHub

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<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <title>hello color web</title>
    <style>
        * {
            margin: 0;
            padding: 0;
            border: none;
        }
        html, body {
            height: 100%;
            width: 100%;
        }
        iframe {
            display: block;
        }
    </style>
</head>
<body>
    <iframe
        id="frame"
        src=""
        width="100%"
        height="100%"
    ></iframe>
    <script>
        const frame = document.getElementById('frame');
        const baseUrl = './14_hello_mqtt-inner.html'
        // heartbeat detection
        let lastHeartbeat = 0;
        window.addEventListener('message', (event) => {
            if (event.origin !== window.location.origin) {
                return;
            }
            lastHeartbeat = Date.now();
        })
        const testHeartbeat = () => {
            const now = Date.now();
            if(lastHeartbeat < now - 5000) {
                console.log('it ded, reload')
                frame.src = baseUrl + '?time=' + now;
            }
        }
        testHeartbeat();
        setInterval(
            testHeartbeat,
            5000,
        );
    </script>
</body>
</html>