FEATURE: Site Customizations can use the plugin api

app/assets/javascripts/discourse.js

@@ -6,6 +6,8 @@ define('ember', ['exports'], function(__exports__) {
   __exports__.default = Ember;
 });
 
+var _pluginCallbacks = [];
+
 window.Discourse = Ember.Application.createWithMixins(Discourse.Ajax, {
   rootElement: '#main',
   _docTitle: document.title,
@@ -127,6 +129,18 @@ window.Discourse = Ember.Application.createWithMixins(Discourse.Ajax, {
       }
     });
 
+    // Plugins that are registered via `<script>` tags.
+    var withPluginApi = require('discourse/lib/plugin-api').withPluginApi;
+    var initCount = 0;
+    _pluginCallbacks.forEach(function(cb) {
+      Discourse.instanceInitializer({
+        name: "_discourse_plugin_" + (++initCount),
+        after: 'inject-objects',
+        initialize: function() {
+          withPluginApi(cb.version, cb.code);
+        }
+      });
+    });
   },
 
   requiresRefresh: function(){
@@ -134,6 +148,9 @@ window.Discourse = Ember.Application.createWithMixins(Discourse.Ajax, {
     return desired && Discourse.get("currentAssetVersion") !== desired;
   }.property("currentAssetVersion", "desiredAssetVersion"),
 
+  _registerPluginCode(version, code) {
+    _pluginCallbacks.push({ version: version, code: code });
+  },
 
   assetVersion: Ember.computed({
     get: function() {

app/models/site_customization.rb

@@ -27,6 +27,17 @@ class SiteCustomization < ActiveRecord::Base
     raise e
   end
 
+  def transpile(es6_source, version)
+    template  = Tilt::ES6ModuleTranspilerTemplate.new {}
+    wrapped = <<PLUGIN_API_JS
+Discourse._registerPluginCode('#{version}', api => {
+  #{es6_source}
+});
+PLUGIN_API_JS
+
+    template.babel_transpile(wrapped)
+  end
+
   def process_html(html)
     doc = Nokogiri::HTML.fragment(html)
     doc.css('script[type="text/x-handlebars"]').each do |node|
@@ -43,6 +54,17 @@ SCRIPT
       node.replace("<script>#{compiled}</script>")
     end
 
+    doc.css('script[type="text/discourse-plugin"]').each do |node|
+      if node['version'].present?
+        begin
+          code = transpile(node.inner_html, node['version'])
+          node.replace("<script>#{code}</script>")
+        rescue Tilt::ES6ModuleTranspilerTemplate::JavaScriptError => ex
+          node.replace("<script type='text/discourse-js-error'>#{ex.message}</script>")
+        end
+      end
+    end
+
     doc.to_s
   end