Question

我有一个简单的html页面

<!DOCTYPE html>
<html>
<head>
    <title>Sample</title>
</head>
<body>
    <div>
        Simple div
    </div>
</body>
</html>

我在Chrome中打开了这个HTML文档。然后在调试器工具中，执行以下

document.getElementsByTagName("script")[0]

我有一个脚本标记（我从未在HTML中添加），附带了一堆代码，如下面的

<script type="text/javascript">
    // <![CDATA[  <-- For SVG support
    if ('WebSocket' in window) {
        (function() {
            function refreshCSS() {
                var sheets = [].slice.call(document.getElementsByTagName("link"));
                var head = document.getElementsByTagName("head")[0];
                for (var i = 0; i < sheets.length; ++i) {
                    var elem = sheets[i];
                    head.removeChild(elem);
                    var rel = elem.rel;
                    if (elem.href && typeof rel != "string" || rel.length == 0 || rel.toLowerCase() == "stylesheet") {
                        var url = elem.href.replace(/(&|\?)_cacheOverride=\d+/, '');
                        elem.href = url + (url.indexOf('?') >= 0 ? '&' : '?') + '_cacheOverride=' + (new Date().valueOf());
                    }
                    head.appendChild(elem);
                }
            }
            var protocol = window.location.protocol === 'http:' ? 'ws://' : 'wss://';
            var address = protocol + window.location.host + window.location.pathname + '/ws';
            var socket = new WebSocket(address);
            socket.onmessage = function(msg) {
                if (msg.data == 'reload') window.location.reload();
                else if (msg.data == 'refreshcss') refreshCSS();
            };
            if(sessionStorage && !sessionStorage.getItem('IsThisFirstTime_Log_From_LiveServer'))
            {
                console.log('Live reload enabled.');
                sessionStorage.setItem('IsThisFirstTime_Log_From_LiveServer', true);
            }
        })();
    }
    else {
        console.error('Upgrade your browser. This Browser is NOT supported WebSocket for Live-Reloading.');
    }
    // ]]>
</script>

有人能告诉我这是什么，为什么会这样？

Answer 1

来自vscode-live-server： https://github.com/ritwickdey/vscode-live-server/blob/master/lib/live-server/injected.html

HTML文档中的不可见脚本标记，其中包含websockets代码

1 个答案: