Unescaped Markup: Improvements

plugins/unescaped-markup/prism-unescaped-markup.js

@@ -4,41 +4,59 @@
 		return;
 	}
 
+	// https://developer.mozilla.org/en-US/docs/Web/API/Element/matches#Polyfill
+	if (!Element.prototype.matches) {
+		Element.prototype.matches = Element.prototype.msMatchesSelector || Element.prototype.webkitMatchesSelector;
+	}
+
+
 	Prism.plugins.UnescapedMarkup = true;
 
 	Prism.hooks.add('before-highlightall', function (env) {
-		env.selector += ", [class*='lang-'] script[type='text/plain'], [class*='language-'] script[type='text/plain']" +
-		                ", script[type='text/plain'][class*='lang-'], script[type='text/plain'][class*='language-']";
+		env.selector += ', [class*="lang-"] script[type="text/plain"]'
+			+ ', [class*="language-"] script[type="text/plain"]'
+			+ ', script[type="text/plain"][class*="lang-"]'
+			+ ', script[type="text/plain"][class*="language-"]';
 	});
 
 	Prism.hooks.add('before-sanity-check', function (env) {
-		if ((env.element.matches || env.element.msMatchesSelector).call(env.element, "script[type='text/plain']")) {
-			var code = document.createElement("code");
-			var pre = document.createElement("pre");
-
-			pre.className = code.className = env.element.className;
-
-			if (env.element.dataset) {
-				Object.keys(env.element.dataset).forEach(function (key) {
-					if (Object.prototype.hasOwnProperty.call(env.element.dataset, key)) {
-						pre.dataset[key] = env.element.dataset[key];
-					}
-				});
-			}
+		/** @type {HTMLElement} */
+		var element = env.element;
+
+		if (element.matches('script[type="text/plain"]')) {
+			// found a <script type="text/plain" ...> element
+			// we convert this element to a regular <pre><code> code block
 
-			env.code = env.code.replace(/&lt;\/script(>|&gt;)/gi, "</scri" + "pt>");
-			code.textContent = env.code;
+			var code = document.createElement('code');
+			var pre = document.createElement('pre');
 
+			// copy class name
+			pre.className = code.className = element.className;
+
+			// copy all "data-" attributes
+			var dataset = element.dataset;
+			Object.keys(dataset || {}).forEach(function (key) {
+				if (Object.prototype.hasOwnProperty.call(dataset, key)) {
+					pre.dataset[key] = dataset[key];
+				}
+			});
+
+			code.textContent = env.code = env.code.replace(/&lt;\/script(?:>|&gt;)/gi, '</scri' + 'pt>');
+
+			// change DOM
 			pre.appendChild(code);
-			env.element.parentNode.replaceChild(pre, env.element);
+			element.parentNode.replaceChild(pre, element);
 			env.element = code;
 			return;
 		}
 
-		var pre = env.element.parentNode;
-		if (!env.code && pre && pre.nodeName.toLowerCase() == 'pre' &&
-				env.element.childNodes.length && env.element.childNodes[0].nodeName == "#comment") {
-			env.element.textContent = env.code = env.element.childNodes[0].textContent;
+		if (!env.code) {
+			// no code
+			var childNodes = element.childNodes;
+			if (childNodes.length === 1 && childNodes[0].nodeName == '#comment') {
+				// the only child is a comment -> use the comment's text
+				element.textContent = env.code = childNodes[0].textContent;
+			}
 		}
 	});
 }());