Autoloader: Fixed data-dependencies and extensions (#2326)

plugins/autoloader/prism-autoloader.js

@@ -269,42 +269,54 @@
 	}
 
 	/**
-	 * Returns the path to a grammar, using the language_path and use_minified config keys.
+	 * Returns all additional dependencies of the given element defined by the `data-dependencies` attribute.
 	 *
-	 * @param {string} lang
-	 * @returns {string}
+	 * @param {Element} element
+	 * @returns {string[]}
 	 */
-	function getLanguagePath(lang) {
-		return config.languages_path +
-			'prism-' + lang
-			+ (config.use_minified ? '.min' : '') + '.js'
+	function getDependencies(element) {
+		var deps = (element.getAttribute('data-dependencies') || '').trim();
+		if (!deps) {
+			var parent = element.parentElement;
+			if (parent && parent.tagName.toLowerCase() === 'pre') {
+				deps = (parent.getAttribute('data-dependencies') || '').trim();
+			}
+		}
+		return deps ? deps.split(/\s*,\s*/g) : [];
 	}
 
 	/**
-	 * Tries to load the grammar(s) and once loaded, highlights the given element again.
+	 * Returns whether the given language is currently loaded.
 	 *
 	 * @param {string} lang
-	 * @param {HTMLElement} elt
+	 * @returns {boolean}
 	 */
-	function registerElement(lang, elt) {
-		if (lang in lang_aliases) {
-			lang = lang_aliases[lang];
+	function isLoaded(lang) {
+		if (lang.indexOf('!') >= 0) {
+			// forced reload
+			return false;
 		}
 
-		// Look for additional dependencies defined on the <code> or <pre> tags
-		var deps = (elt.getAttribute('data-dependencies') || '').trim();
-		if (!deps) {
-			var parent = elt.parentElement;
-			if (parent && parent.tagName.toLowerCase() === 'pre') {
-				deps = (parent.getAttribute('data-dependencies') || '').trim();
-			}
+		lang = lang_aliases[lang] || lang; // resolve alias
+
+		if (lang in Prism.languages) {
+			// the given language is already loaded
+			return true;
 		}
 
-		loadLanguages(deps ? deps.split(/\s*,\s*/g) : [], function () {
-			loadLanguage(lang, function () {
-				Prism.highlightElement(elt);
-			});
-		});
+		// this will catch extensions like CSS extras that don't add a grammar to Prism.languages
+		var data = lang_data[lang];
+		return data && !data.error && data.loading === false;
+	}
+
+	/**
+	 * Returns the path to a grammar, using the language_path and use_minified config keys.
+	 *
+	 * @param {string} lang
+	 * @returns {string}
+	 */
+	function getLanguagePath(lang) {
+		return config.languages_path + 'prism-' + lang + (config.use_minified ? '.min' : '') + '.js'
 	}
 
 	/**
@@ -364,7 +376,7 @@
 		lang = lang.replace('!', '');
 		lang = lang_aliases[lang] || lang;
 
-		var load = function () {
+		function load() {
 			var data = lang_data[lang];
 			if (!data) {
 				data = lang_data[lang] = {
@@ -376,21 +388,25 @@
 				error: error
 			});
 
-			if (!force && Prism.languages[lang]) {
-				languageCallback(lang, "success");
+			if (!force && isLoaded(lang)) {
+				// the language is already loaded and we aren't forced to reload
+				languageCallback(lang, 'success');
 			} else if (!force && data.error) {
-				languageCallback(lang, "error");
+				// the language failed to load before and we don't reload
+				languageCallback(lang, 'error');
 			} else if (force || !data.loading) {
+				// the language isn't currently loading and/or we are forced to reload
 				data.loading = true;
-				var src = getLanguagePath(lang);
-				addScript(src, function () {
+				data.error = false;
+
+				addScript(getLanguagePath(lang), function () {
 					data.loading = false;
-					languageCallback(lang, "success");
+					languageCallback(lang, 'success');
 
 				}, function () {
 					data.loading = false;
 					data.error = true;
-					languageCallback(lang, "error");
+					languageCallback(lang, 'error');
 				});
 			}
 		};
@@ -423,10 +439,20 @@
 	}
 
 	Prism.hooks.add('complete', function (env) {
-		if (env.element && env.language && !env.grammar) {
-			if (env.language !== ignored_language) {
-				registerElement(env.language, env.element);
-			}
+		var element = env.element;
+		var language = env.language;
+		if (!element || !language || language === ignored_language) {
+			return;
+		}
+
+		var deps = getDependencies(element);
+		deps.push(language);
+
+		if (!deps.every(isLoaded)) {
+			// the language or some dependencies aren't loaded
+			loadLanguages(dependencies, function () {
+				Prism.highlightElement(element);
+			});
 		}
 	});