Commit b679cfe6feb99c08bcd846e2a9903c575ad2c5db

Michael Schmidt 2021-11-03T13:07:32

Keep Markup: Added `drop-tokens` option class (#3166)

diff --git a/plugins/keep-markup/index.html b/plugins/keep-markup/index.html
index 01d5269..542ef4e 100644
--- a/plugins/keep-markup/index.html
+++ b/plugins/keep-markup/index.html
@@ -27,7 +27,7 @@
 	<script>var _gaq = [['_setAccount', 'UA-33746269-1'], ['_trackPageview']];</script>
 	<script src="https://www.google-analytics.com/ga.js" async></script>
 </head>
-<body>
+<body class="language-none">
 
 <header data-plugin-header="keep-markup"></header>
 
@@ -39,6 +39,12 @@
 
 	<p>However, you can deactivate the plugin for certain code element by adding the <code>no-keep-markup</code> class to it. You can also deactivate the plugin for the whole page by adding the <code>no-keep-markup</code> class to the body of the page and then selectively activate it again by adding the <code>keep-markup</code> class to code elements.</p>
 
+	<h2>Double highlighting</h2>
+
+	<p>Some plugins (e.g. <a href="plugins/autoloader">Autoloader</a>) need to re-highlight code blocks. This is a problem for Keep Markup because it will keep the markup of the first highlighting pass resulting in a lot of unnecessary DOM nodes and causing problems for themes and other plugins.</p>
+
+	<p>This problem can be fixed by adding a <code>drop-tokens</code> class to a code block or any of its ancestors. If <code>drop-tokens</code> is present, Keep Markup will ignore all <code class="language-css">span.token</code> elements created by Prism.</p>
+
 	<h1>Examples</h1>
 
 	<p>The following source code</p>
diff --git a/plugins/keep-markup/prism-keep-markup.js b/plugins/keep-markup/prism-keep-markup.js
index 267d9d9..c160faa 100644
--- a/plugins/keep-markup/prism-keep-markup.js
+++ b/plugins/keep-markup/prism-keep-markup.js
@@ -15,31 +15,53 @@
 			return;
 		}
 
+		var dropTokens = Prism.util.isActive(env.element, 'drop-tokens', false);
+		/**
+		 * Returns whether the given element should be kept.
+		 *
+		 * @param {HTMLElement} element
+		 * @returns {boolean}
+		 */
+		function shouldKeep(element) {
+			if (dropTokens && element.nodeName.toLowerCase() === 'span' && element.classList.contains('token')) {
+				return false;
+			}
+			return true;
+		}
+
 		var pos = 0;
 		var data = [];
-		var f = function (elt, baseNode) {
-			var o = {};
-			if (!baseNode) {
-				// Clone the original tag to keep all attributes
-				o.clone = elt.cloneNode(false);
-				o.posOpen = pos;
-				data.push(o);
+		function processElement(element) {
+			if (!shouldKeep(element)) {
+				// don't keep this element and just process its children
+				processChildren(element);
+				return;
 			}
-			for (var i = 0, l = elt.childNodes.length; i < l; i++) {
-				var child = elt.childNodes[i];
+
+			var o = {
+				// Clone the original tag to keep all attributes
+				clone: element.cloneNode(false),
+				posOpen: pos
+			};
+			data.push(o);
+
+			processChildren(element);
+
+			o.posClose = pos;
+		}
+		function processChildren(element) {
+			for (var i = 0, l = element.childNodes.length; i < l; i++) {
+				var child = element.childNodes[i];
 				if (child.nodeType === 1) { // element
-					f(child);
+					processElement(child);
 				} else if (child.nodeType === 3) { // text
 					pos += child.data.length;
 				}
 			}
-			if (!baseNode) {
-				o.posClose = pos;
-			}
-		};
-		f(env.element, true);
+		}
+		processChildren(env.element);
 
-		if (data && data.length) {
+		if (data.length) {
 			// data is an array of all existing tags
 			env.keepMarkup = data;
 		}
diff --git a/plugins/keep-markup/prism-keep-markup.min.js b/plugins/keep-markup/prism-keep-markup.min.js
index 229c510..6bea9d2 100644
--- a/plugins/keep-markup/prism-keep-markup.min.js
+++ b/plugins/keep-markup/prism-keep-markup.min.js
@@ -1 +1 @@
-"undefined"!=typeof Prism&&"undefined"!=typeof document&&document.createRange&&(Prism.plugins.KeepMarkup=!0,Prism.hooks.add("before-highlight",function(e){if(e.element.children.length&&Prism.util.isActive(e.element,"keep-markup",!0)){var a=0,s=[],p=function(e,n){var o={};n||(o.clone=e.cloneNode(!1),o.posOpen=a,s.push(o));for(var t=0,d=e.childNodes.length;t<d;t++){var r=e.childNodes[t];1===r.nodeType?p(r):3===r.nodeType&&(a+=r.data.length)}n||(o.posClose=a)};p(e.element,!0),s&&s.length&&(e.keepMarkup=s)}}),Prism.hooks.add("after-highlight",function(n){if(n.keepMarkup&&n.keepMarkup.length){var a=function(e,n){for(var o=0,t=e.childNodes.length;o<t;o++){var d=e.childNodes[o];if(1===d.nodeType){if(!a(d,n))return!1}else 3===d.nodeType&&(!n.nodeStart&&n.pos+d.data.length>n.node.posOpen&&(n.nodeStart=d,n.nodeStartPos=n.node.posOpen-n.pos),n.nodeStart&&n.pos+d.data.length>=n.node.posClose&&(n.nodeEnd=d,n.nodeEndPos=n.node.posClose-n.pos),n.pos+=d.data.length);if(n.nodeStart&&n.nodeEnd){var r=document.createRange();return r.setStart(n.nodeStart,n.nodeStartPos),r.setEnd(n.nodeEnd,n.nodeEndPos),n.node.clone.appendChild(r.extractContents()),r.insertNode(n.node.clone),r.detach(),!1}}return!0};n.keepMarkup.forEach(function(e){a(n.element,{node:e,pos:0})}),n.highlightedCode=n.element.innerHTML}}));
\ No newline at end of file
+"undefined"!=typeof Prism&&"undefined"!=typeof document&&document.createRange&&(Prism.plugins.KeepMarkup=!0,Prism.hooks.add("before-highlight",function(e){if(e.element.children.length&&Prism.util.isActive(e.element,"keep-markup",!0)){var o=Prism.util.isActive(e.element,"drop-tokens",!1),d=0,t=[];s(e.element),t.length&&(e.keepMarkup=t)}function r(e){if(function(e){return!o||"span"!==e.nodeName.toLowerCase()||!e.classList.contains("token")}(e)){var n={clone:e.cloneNode(!1),posOpen:d};t.push(n),s(e),n.posClose=d}else s(e)}function s(e){for(var n=0,o=e.childNodes.length;n<o;n++){var t=e.childNodes[n];1===t.nodeType?r(t):3===t.nodeType&&(d+=t.data.length)}}}),Prism.hooks.add("after-highlight",function(n){if(n.keepMarkup&&n.keepMarkup.length){var s=function(e,n){for(var o=0,t=e.childNodes.length;o<t;o++){var d=e.childNodes[o];if(1===d.nodeType){if(!s(d,n))return!1}else 3===d.nodeType&&(!n.nodeStart&&n.pos+d.data.length>n.node.posOpen&&(n.nodeStart=d,n.nodeStartPos=n.node.posOpen-n.pos),n.nodeStart&&n.pos+d.data.length>=n.node.posClose&&(n.nodeEnd=d,n.nodeEndPos=n.node.posClose-n.pos),n.pos+=d.data.length);if(n.nodeStart&&n.nodeEnd){var r=document.createRange();return r.setStart(n.nodeStart,n.nodeStartPos),r.setEnd(n.nodeEnd,n.nodeEndPos),n.node.clone.appendChild(r.extractContents()),r.insertNode(n.node.clone),r.detach(),!1}}return!0};n.keepMarkup.forEach(function(e){s(n.element,{node:e,pos:0})}),n.highlightedCode=n.element.innerHTML}}));
\ No newline at end of file
diff --git a/tests/plugins/keep-markup/test.js b/tests/plugins/keep-markup/test.js
index 006ce3c..9f57768 100644
--- a/tests/plugins/keep-markup/test.js
+++ b/tests/plugins/keep-markup/test.js
@@ -4,6 +4,7 @@ const { createScopedPrismDom } = require('../../helper/prism-dom-util');
 
 describe('Keep Markup', function () {
 	const { Prism, document } = createScopedPrismDom(this, {
+		languages: 'javascript',
 		plugins: 'keep-markup'
 	});
 
@@ -42,6 +43,25 @@ describe('Keep Markup', function () {
 		keepMarkup(`xy<a>a</a>`);
 	});
 
+	it('should support double highlighting', function () {
+		const pre = document.createElement('pre');
+		pre.className = 'language-javascript drop-tokens';
+		pre.innerHTML = '<code>var <mark>a = 42</mark>;</code>';
+		const code = pre.childNodes[0];
+		const initial = code.innerHTML;
+
+		Prism.highlightElement(code);
+		const firstPass = code.innerHTML;
+
+		Prism.highlightElement(code);
+		const secondPass = code.innerHTML;
+
+		// check that we actually did some highlighting
+		assert.notStrictEqual(initial, firstPass);
+		// check that the highlighting persists
+		assert.strictEqual(firstPass, secondPass);
+	});
+
 	// The markup is removed if it's the last element and the element's name is a single letter: a(nchor), b(old), i(talic)...
 	// https://github.com/PrismJS/prism/issues/1618
 	/*