Custom class: Added mapper functions for language specific transforma…

…tions (#1873)

This adds support for mapper function to the `map` function, allowing for language-specific transformations.

plugins/custom-class/index.html

@@ -52,10 +52,20 @@ <h2>2. Replace some Prism classes with your defined ones via an object</h2>
 	keyword: 'special-keyword',
 	string: 'string_ch29s',
 	comment: 'comment_93jsa'
-})</code></pre>
+});</code></pre>
 
 	<p>Object's keys are the tokens you want to replace (eg: <code>comment</code>), with their values being the classes you want to use (eg: <code>my-comment</code>). Tokens which are not specified will stay the same.</p>
 
+	<p>Alternatively you can also pass a function that takes the original class and returns the mapped class. This function can also be used implement language specific mapped classes.<br>Example:</p>
+
+	<pre class="language-js"><code>Prism.plugins.customClass.map(function (className, language) {
+	if (language === 'css') {
+		return cssSpecificMap[className] || className;
+	} else {
+		return className;
+	}
+});</code></pre>
+
 	<h1>Notes</h1>
 
 	<ul>
@@ -113,14 +123,6 @@ <h2>Output</h2>
 &lt;/code&gt;&lt;/pre&gt;</code></pre>
 </section>
 
-<section>
-	<h1>Todo</h1>
-	<ul>
-		<li>Take a function as the transformation (<a href="https://github.com/PrismJS/prism/pull/950#issuecomment-224289585">Comment in #950</a></li>
-		<li>Allow to custom tokens per language, using nested object (<a href="https://github.com/PrismJS/prism/issues/947#issuecomment-216979932">Comment in #947</a>)</li>
-	</ul>
-</section>
-
 <footer data-src="templates/footer.html" data-type="text/html"></footer>
 
 <script src="prism.js"></script>

plugins/custom-class/prism-custom-class.js

@@ -7,24 +7,61 @@ if (
 	return;
 }
 
+/**
+ * @callback ClassMapper
+ * @param {string} className
+ * @param {string} language
+ * @returns {string}
+ */
+/**
+ * @typedef CustomClassOptions
+ * @property {ClassMapper} classMap
+ * @property {string} prefixString
+ */
+
+/** @type {ClassMapper} */
+var defaultClassMap = function (className) { return className; };
+
+/** @type {CustomClassOptions} */
 var options = {
-	classMap: {}
+	classMap: defaultClassMap,
+	prefixString: ''
 };
+
 Prism.plugins.customClass = {
-	map: function map(cm) {
-		options.classMap = cm;
+	/**
+	 * Maps all class names using the given object or map function.
+	 *
+	 * This does not affect the prefix.
+	 *
+	 * @param {Object<string, string> | ClassMapper} classMap
+	 */
+	map: function map(classMap) {
+		if (typeof classMap === 'function') {
+			options.classMap = classMap;
+		} else {
+			options.classMap = function (className) {
+				return classMap[className] || className;
+			};
+		}
 	},
+	/**
+	 * Adds the given prefix to all class names.
+	 *
+	 * @param {string} string
+	 */
 	prefix: function prefix(string) {
 		options.prefixString = string;
 	}
 }
 
 Prism.hooks.add('wrap', function (env) {
-	if (!options.classMap && !options.prefixString) {
+	if (options.classMap === defaultClassMap && !options.prefixString) {
 		return;
 	}
-	env.classes = env.classes.map(function(c) {
-		return (options.prefixString || '') + (options.classMap[c] || c);
+
+	env.classes = env.classes.map(function (c) {
+		return options.prefixString + options.classMap(c, env.language);
 	});
 });