FEATURE: Allow selection of highlight js languages

PERF: stop loading highlight js on load

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

config/application.rb

@@ -32,6 +32,9 @@ module Discourse
     require 'es6_module_transpiler/rails'
     require 'js_locale_helper'
 
+    # tiny file needed by site settings
+    require 'highlight_js/highlight_js'
+
     # mocha hates us, active_support/testing/mochaing.rb line 2 is requiring the wrong
     #  require, patched in source, on upgrade remove this
     if Rails.env.test? || Rails.env.development?

config/initializers/06-mini_profiler.rb

@@ -27,6 +27,7 @@ if defined?(Rack::MiniProfiler)
     (path !~ /assets/) &&
     (path !~ /\/user_avatar\//) &&
     (path !~ /\/letter_avatar\//) &&
+    (path !~ /\/highlight-js\//) &&
     (path !~ /qunit/) &&
     (path !~ /srv\/status/) &&
     (path !~ /commits-widget/) &&

config/locales/server.en.yml

@@ -1104,6 +1104,7 @@ en:
     default_code_lang: "Default programming language syntax highlighting applied to GitHub code blocks (lang-auto, ruby, python etc.)"
     warn_reviving_old_topic_age: "When someone starts replying to a topic where the last reply is older than this many days, a warning will be displayed. Disable by setting to 0."
     autohighlight_all_code: "Force apply code highlighting to all preformatted code blocks even when they didn't explicitly specify the language."
+    highlighted_languages: "Included syntax highlighting rules. (Warning: including too many langauges may impact performance) see: https://highlightjs.org/static/demo/ for a demo"
 
     embeddable_host: "Host that can embed the comments from this Discourse forum. Hostname only, do not begin with http://"
     feed_polling_enabled: "EMBEDDING ONLY: Whether to embed a RSS/ATOM feed as posts."

config/nginx.sample.conf

@@ -158,7 +158,7 @@ server {
     # This big block is needed so we can selectively enable
     # acceleration for backups and avatars
     # see note about repetition above
-    location ~ ^/(letter_avatar|user_avatar) {
+    location ~ ^/(letter_avatar|user_avatar|highlight-js) {
       proxy_set_header Host $http_host;
       proxy_set_header X-Real-IP $remote_addr;
       proxy_set_header X-Forwarded-For $proxy_add_x_forwarded_for;

config/routes.rb

@@ -274,6 +274,8 @@ Discourse::Application.routes.draw do
   get "letter_avatar/:username/:size/:version.png" => "user_avatars#show_letter", format: false, constraints: { hostname: /[\w\.-]+/ }
   get "user_avatar/:hostname/:username/:size/:version.png" => "user_avatars#show", format: false, constraints: { hostname: /[\w\.-]+/ }
 
+  get "highlight-js/:hostname/:version.js" => "highlight_js#show", format: false, constraints: { hostname: /[\w\.-]+/ }
+
   get "uploads/:site/:id/:sha.:extension" => "uploads#show", constraints: {site: /\w+/, id: /\d+/, sha: /[a-z0-9]{15,16}/i, extension: /\w{2,}/}
   get "uploads/:site/:sha" => "uploads#show", constraints: { site: /\w+/, sha: /[a-z0-9]{40}/}
   post "uploads" => "uploads#create"

config/site_settings.yml

@@ -400,6 +400,11 @@ posting:
   autohighlight_all_code:
     client: true
     default: false
+  highlighted_languages:
+    default: 'apache|bash|cs|cpp|css|coffeescript|diff|xml|http|ini|json|java|javascript|makefile|markdown|nginx|objectivec|ruby|perl|php|python|sql|handlebars'
+    choices: 'HighlightJs.languages'
+    type: list
+    client: true
   delete_old_hidden_posts: true
   censored_words:
     client: true