FEATURE: Allow selection of highlight js languages

PERF: stop loading highlight js on load

To get latest highlight js run bin/rake highlightjs:update

app/assets/javascripts/discourse/dialects/code_dialect.js

@@ -2,13 +2,22 @@
   Support for various code blocks
 **/
 
-var acceptableCodeClasses =
-  ["auto", "1c", "actionscript", "apache", "applescript", "avrasm", "axapta", "bash", "brainfuck",
-   "clojure", "cmake", "coffeescript", "cpp", "cs", "css", "d", "delphi", "diff", "xml", "django", "dos",
-   "erlang-repl", "erlang", "glsl", "go", "handlebars", "haskell", "http", "ini", "java", "javascript",
-   "json", "lisp", "lua", "markdown", "matlab", "mel", "nginx", "nohighlight", "objectivec", "parser3",
-   "perl", "php", "profile", "python", "r", "rib", "rsl", "ruby", "rust", "scala", "smalltalk", "sql",
-   "tex", "text", "vala", "vbscript", "vhdl"];
+var acceptableCodeClasses;
+
+function init() {
+  acceptableCodeClasses = Discourse.SiteSettings.highlighted_languages.split("|");
+  if (Discourse.SiteSettings.highlighted_languages.length > 0) {
+    var regexpSource = "^lang-(" + "nohighlight|auto|" + Discourse.SiteSettings.highlighted_languages + ")$";
+    Discourse.Markdown.whiteListTag('code', 'class', new RegExp(regexpSource, "i"));
+  }
+}
+
+if (Discourse.SiteSettings && Discourse.SiteSettings.highlighted_languages) {
+  init();
+} else {
+  Discourse.initializer({initialize: init, name: 'load-acceptable-code-classes'});
+}
+
 
 var textCodeClasses = ["text", "pre", "plain"];
 
@@ -27,6 +36,7 @@ Discourse.Dialect.replaceBlock({
   emitter: function(blockContents, matches) {
 
     var klass = Discourse.SiteSettings.default_code_lang;
+
     if (matches[1] && acceptableCodeClasses.indexOf(matches[1]) !== -1) {
       klass = matches[1];
     }
@@ -69,6 +79,3 @@ Discourse.Dialect.on('parseNode', function (event) {
   }
 });
 
-// Whitelist the language classes
-var regexpSource = "^lang-(" + acceptableCodeClasses.join('|') + ")$";
-Discourse.Markdown.whiteListTag('code', 'class', new RegExp(regexpSource, "i"));

app/assets/javascripts/discourse/lib/highlight-syntax.js.es6

@@ -5,6 +5,6 @@ import loadScript from 'discourse/lib/load-script';
 export default function highlightSyntax($elem) {
   const selector = Discourse.SiteSettings.autohighlight_all_code ? 'pre code' : 'pre code[class]';
   $(selector, $elem).each(function(i, e) {
-    loadScript("/javascripts/highlight.pack.js").then(() => hljs.highlightBlock(e));
+    loadScript(Discourse.HighlightJSPath).then(() => hljs.highlightBlock(e));
   });
 }

app/assets/javascripts/discourse/lib/load-script.js.es6

@@ -31,13 +31,19 @@ export default function loadScript(url, opts) {
       resolve();
     };
 
+    var cdnUrl = url;
+
+    if (Discourse.CDN && url[0] === "/") {
+      cdnUrl = Discourse.CDN + url;
+    }
+
     // Some javascript depends on the path of where it is loaded (ace editor)
     // to dynamically load more JS. In that case, add the `scriptTag: true`
     // option.
     if (opts.scriptTag) {
-      loadWithTag(url, cb);
+      loadWithTag(cdnUrl, cb);
     } else {
-      $.getScript(url).then(cb);
+      $.getScript(cdnUrl).then(cb);
     }
   });
 }

app/assets/javascripts/main_include.js

@@ -4,11 +4,6 @@
 // Pagedown customizations
 //= require ./pagedown_custom.js
 
-// This is a BUG we should fix
-// it is only required here cause preview is not loading it using LAB
-//= require highlight.pack.js
-//
-
 // Stuff we need to load first
 //= require ./discourse/lib/load-script
 //= require ./discourse/lib/notification-levels