<script>标记在<noscript>标记内的用途是什么？

Question

我最近在有趣的设计和内容的网站上进行了"观察源"狂欢.其中一个网站Squarespace在<script>标签内部有<noscript>标签块,如下所示:

<!-- Page is at: http://squarespace.com -->
...
...
<noscript id="inline-deps">
  <link rel="stylesheet" type="text/css" href="//cloud.typography.com/7811972/758964/css/fonts.css" />

  <script type="text/javascript" src="https://static.squarespace.com/static/ta/5134cbefe4b0c6fb04df8065/7400/assets/logomark/logomark.min.js?37"></script>
  <link rel="stylesheet" href="https://static.squarespace.com/static/ta/5134cbefe4b0c6fb04df8065/7400/assets/logomark/logomark.min.css?37" type="text/css" />
</noscript>
...
...

它让我感到很奇怪,并让我谷歌搜索信息,看看是否有某种隐藏的功能/目的这样奇怪的HTML,但无济于事.<script>在<noscript>元素中使用标记是否有某种目的,或者这只是坏HTML的一个例子？

Answer 1

我做了一些搜索他们的代码并找到了这个片段(我已将其清理干净以使其更具可读性):

var DepLoader = (function () {
  function init() {
    var dependencies = document.getElementById("inline-deps");
    if (!dependencies || JS.hasClass(document.body, "deps--loaded")) {
      webfontsReady();
    } else {
      var html = dependencies.innerText || dependencies.textContent;
      JS.addClass(document.body, "deps--loaded");
      processRaw(html);
    }
  }

  function isListed(a, b) {
    for (var i = 0; i < b.length; i++) {
      if (a.indexOf(b[i]) !== -1) {
        return true;
      }
    }
    return false;
  }

  function webfontsReady() {
    JS.fireCustom("webfontsReady");
  }

  function processRaw(html) {
    var el = document.createElement("div");
    el.innerHTML = html;

    var scripts = el.querySelectorAll("script");
    var styles = el.querySelectorAll("link");
    var common, signup, dialog, systemPage, commerce;
    var others = [];
    var inline = [];
    var styleWhiteList = ["site.css", "dialog-", "signup-", "logomark"];
    var scriptBlackList = ["management-", "ckeditor-"];

    for (var i = 0; i < styles.length; i++) {
      var style = styles[i];
      if (style.href.indexOf("fonts.css") !== -1) load(style, webfontsReady);
      if (isListed(style.href, styleWhiteList)) load(style);
    }

    for (var i = 0; i < scripts.length; i++) {
      var script = scripts[i];
      var src = script.src;

      if (!src && script.getAttribute("data-sqs-type") !== "dynamic-assets-loader" && script.innerHTML.indexOf("SQUARESPACE_ROLLUPS") === -1) {
        eval(script.innerHTML);
      }
    }

    if (window.SQUARESPACE_ROLLUPS) {
      for (var key in SQUARESPACE_ROLLUPS) {
        var rollup = SQUARESPACE_ROLLUPS[key];
        var js = rollup.js;
        var css = rollup.css;

        if (key.indexOf("common") !== -1) {
          common = js;
        } else if (key.indexOf("commerce") !== -1) {
          commerce = js;
        } else if (key.indexOf("signup") !== -1) {
          signup = js;
        } else if (key.indexOf("dialog") !== -1) {
          dialog = js;
        } else if (key.indexOf("system-page") !== -1) {
          systemPage = js;
        } else if (key) {
          others = others.concat(js);
        } else {
          inline = inline.concat(js);
        }
      }
    }

    for (var i = 0; i < scripts.length; s++) {
      var script = scripts[i];
      var src = script.src;

      if (!isListed(src, scriptBlackList)) {
        if (src.indexOf("common-") !== -1) {
          common = script;
        } else if (src.indexOf("commerce-") !== -1) {
          commerce = script;
        } else if (src.indexOf("signup-") !== -1) {
          signup = script;
        } else if (src.indexOf("dialog-") !== -1) {
          dialog = script;
        } else if (src.indexOf("system-page-") !== -1) {
          systemPage = script;
        } else if (src) {
          others.push(script);
        } else {
          inline.push(script);
        }
      }
    }

    function loadOthers() {
      for (var i = 0; i < inline.length; i++) {
        if (inline[i].getAttribute("data-sqs-type") !== "dynamic-assets-loader") {
          load(inline[a]);
        }
      }

      for (var i = 0; i < others.length; i++) {
          load(others[i]);
      }

      JS.fireCustom("dependenciesLoaded");
    }

    var loadSystemPage = load.bind(this, systemPage, loadOthers, "system page");
    var loadSignup = load.bind(this, signup, loadSystemPage, "signup");
    var loadCommerce = load.bind(this, commerce, loadSignup, "commerce");
    var loadDialog = load.bind(this, dialog, loadCommerce, "dialog");
    var loadCommon = load.bind(this, common, loadDialog, "common");

    loadCommon();
  }

  function load(tag, callback, label) {
    var head = document.head;

    if (Array.isArray(tag)) tag = { nodeName: "SCRIPT", src: tag[0] };

    if (!tag) {
      if (callback) callback();
      return;
    }

    if (tag && (tag.src || tag.href)) {
      var child;
      if ("SCRIPT" === tag.nodeName) {
        child = document.createElement("script");
        child.src = tag.src;

        if (child.src.indexOf("combo") !== -1) {
          callback = function () {
            Y.Squarespace.FrontSite.Core.domReady(true)
          };
        }
      } else {
        if ("LINK" === tag.nodeName && "stylesheet" === tag.rel) {
          child = document.createElement("link");
          child.href = tag.href;
          child.rel = "stylesheet";
          child.tyle = "text/css";
        }

        if (child) {
          child.onload = callback;
          head.appendChild(child);
        }
      }
    } else {
      try {
        eval(tag.innerHTML);
      } catch (e) {}
    }
  }

  return { init: init, webfontsReady: webfontsReady };
})();

如您所见,<noscript>标记具有ID #inline-deps,在代码(第3行)中引用该ID 以异步和按需方式加载依赖项.

它们可能使用一个<noscript>元素,因为它允许它们直接访问DOM元素,而不必将它放在字符串或注释中(我认为特别糟糕,因为注释不适用于实际信息),然后解析它.在特定加载之前,它还会阻止脚本和CSS样式的执行.

我个人认为这是滥用<noscript>标签.我甚至不确定它是否是有效的HTML5代码.在可行的情况下,应使用其他方法,例如在脚本加载器中声明JavaScript对象中的依赖项.