From 5dd752877e0a23c258d9df018ba10d9c6eda97c3 Mon Sep 17 00:00:00 2001
From: Sam <sam.saffron@gmail.com>
Date: Mon, 17 Apr 2017 11:52:43 -0400
Subject: [PATCH] FEATURE: try adding some preload hints for chrome

---
 app/helpers/application_helper.rb              | 12 ++++++------
 .../common/_discourse_javascript.html.erb      |  2 +-
 app/views/common/_special_font_face.html.erb   |  1 +
 app/views/layouts/application.html.erb         | 18 +++++++++---------
 app/views/layouts/embed.html.erb               |  2 +-
 app/views/layouts/finish_installation.html.erb |  4 ++--
 lib/stylesheet/manager.rb                      |  2 +-
 7 files changed, 21 insertions(+), 20 deletions(-)

diff --git a/app/helpers/application_helper.rb b/app/helpers/application_helper.rb
index 67651cc0a55..e534aa50da7 100644
--- a/app/helpers/application_helper.rb
+++ b/app/helpers/application_helper.rb
@@ -45,17 +45,17 @@ module ApplicationHelper
     end
   end
 
-  def script(*args)
+  def preload_script(script)
+    path = asset_path("#{script}.js")
+
     if  GlobalSetting.cdn_url &&
         GlobalSetting.cdn_url.start_with?("https") &&
         ENV["COMPRESS_BROTLI"] == "1" &&
         request.env["HTTP_ACCEPT_ENCODING"] =~ /br/
-      tags = javascript_include_tag(*args)
-      tags.gsub!("#{GlobalSetting.cdn_url}/assets/", "#{GlobalSetting.cdn_url}/brotli_asset/")
-      tags.html_safe
-    else
-      javascript_include_tag(*args)
+        path.gsub!("#{GlobalSetting.cdn_url}/assets/", "#{GlobalSetting.cdn_url}/brotli_asset/")
     end
+"<link rel='preload' href='#{path}' as='script'/>
+<script src='#{path}'></script>".html_safe
   end
 
   def discourse_csrf_tags
diff --git a/app/views/common/_discourse_javascript.html.erb b/app/views/common/_discourse_javascript.html.erb
index 9e2da0a9005..05e0a95f948 100644
--- a/app/views/common/_discourse_javascript.html.erb
+++ b/app/views/common/_discourse_javascript.html.erb
@@ -65,4 +65,4 @@
   })();
 </script>
 
-<%= script 'browser-update' %>
+<%= preload_script 'browser-update' %>
diff --git a/app/views/common/_special_font_face.html.erb b/app/views/common/_special_font_face.html.erb
index 8e95e5ece86..2462461c24e 100644
--- a/app/views/common/_special_font_face.html.erb
+++ b/app/views/common/_special_font_face.html.erb
@@ -10,6 +10,7 @@
 
 <% font_domain = "#{request.protocol}#{request.host_with_port}&2" %>
 
+<link rel="preload" href="<%=asset_path "fontawesome-webfont.woff2"%>" as="font" type="font/woff2" crossorigin />
 <style>
   @font-face {
     font-family: 'FontAwesome';
diff --git a/app/views/layouts/application.html.erb b/app/views/layouts/application.html.erb
index 59100bee029..f86a11fc502 100644
--- a/app/views/layouts/application.html.erb
+++ b/app/views/layouts/application.html.erb
@@ -23,22 +23,22 @@
       window.EmberENV['FORCE_JQUERY'] = true;
     </script>
 
-    <%= script "locales/#{I18n.locale}" %>
-    <%= script "ember_jquery" %>
-    <%= script "preload-store" %>
-    <%= script "vendor" %>
-    <%= script "pretty-text-bundle" %>
-    <%= script "application" %>
+    <%= preload_script "locales/#{I18n.locale}" %>
+    <%= preload_script "ember_jquery" %>
+    <%= preload_script "preload-store" %>
+    <%= preload_script "vendor" %>
+    <%= preload_script "pretty-text-bundle" %>
+    <%= preload_script "application" %>
     <%- if allow_plugins? %>
-    <%= script "plugin" %>
+    <%= preload_script "plugin" %>
     <%- end %>
     <%- if allow_third_party_plugins? %>
-    <%= script "plugin-third-party" %>
+    <%= preload_script "plugin-third-party" %>
     <%- end %>
 
     <%- if staff? %>
       <script src="<%= Discourse.base_uri %>/extra-locales/admin"></script>
-      <%= script "admin" %>
+      <%= preload_script "admin" %>
     <%- end %>
 
     <%- unless customization_disabled? %>
diff --git a/app/views/layouts/embed.html.erb b/app/views/layouts/embed.html.erb
index 975a5b8767f..f1a66ee52b5 100644
--- a/app/views/layouts/embed.html.erb
+++ b/app/views/layouts/embed.html.erb
@@ -7,7 +7,7 @@
     <%- unless customization_disabled? %>
       <%= discourse_stylesheet_link_tag  :embedded_theme %>
     <%- end %>
-    <%= javascript_include_tag 'break_string' %>
+    <%= preload_script 'break_string' %>
 
     <%- if @topic_view && @topic_view.page_title.present? %>
       <title><%= @topic_view.page_title %> - <%= SiteSetting.title %></title>
diff --git a/app/views/layouts/finish_installation.html.erb b/app/views/layouts/finish_installation.html.erb
index 597822c805f..abf274f54fa 100644
--- a/app/views/layouts/finish_installation.html.erb
+++ b/app/views/layouts/finish_installation.html.erb
@@ -2,8 +2,8 @@
   <head>
     <%= discourse_stylesheet_link_tag 'wizard', theme_key: nil %>
     <%= render partial: "common/special_font_face" %>
-    <%= script 'ember_jquery' %>
-    <%= script 'wizard-vendor' %>
+    <%= preload_script 'ember_jquery' %>
+    <%= preload_script 'wizard-vendor' %>
     <%= render partial: "layouts/head" %>
     <title><%= t 'wizard.title' %></title>
   </head>
diff --git a/lib/stylesheet/manager.rb b/lib/stylesheet/manager.rb
index 15ccaee1f23..149ca185573 100644
--- a/lib/stylesheet/manager.rb
+++ b/lib/stylesheet/manager.rb
@@ -36,7 +36,7 @@ class Stylesheet::Manager
       builder = self.new(target, theme_key)
       builder.compile unless File.exists?(builder.stylesheet_fullpath)
       builder.ensure_digestless_file
-      tag = %[<link href="#{builder.stylesheet_path}" media="#{media}" rel="stylesheet" data-target="#{target}"/>]
+      tag = %[<link href="#{builder.stylesheet_path}" media="#{media}" rel="stylesheet" data-target="#{target}" rel="preload"/>]
       cache[cache_key] = tag
 
       tag.dup.html_safe