FEATURE: Include category / subcategory name in document title when

viewing a topic.

app/assets/javascripts/discourse/controllers/topic.js.es6

@@ -23,7 +23,7 @@ export default ObjectController.extend(Discourse.SelectedPostsCount, {
       // and are sometimes lazily loaded.
       this.send('refreshTitle');
     }
-  }.observes('title'),
+  }.observes('title', 'category'),
 
   termChanged: function() {
     var dropdown = this.get('controllers.header.visibleDropdown');

app/assets/javascripts/discourse/routes/discourse_route.js

@@ -21,6 +21,10 @@ Discourse.Route = Ember.Route.extend({
     Em.run.scheduleOnce('afterRender', Discourse.Route, 'cleanDOM');
   },
 
+  _refreshTitleOnce: function() {
+    this.send('_collectTitleTokens', []);
+  },
+
   actions: {
     _collectTitleTokens: function(tokens) {
       // If there's a title token method, call it and get the token
@@ -40,7 +44,7 @@ Discourse.Route = Ember.Route.extend({
     },
 
     refreshTitle: function() {
-      this.send('_collectTitleTokens', []);
+      Ember.run.once(this, this._refreshTitleOnce);
     }
   },
 

app/assets/javascripts/discourse/routes/topic_route.js

@@ -15,7 +15,20 @@ Discourse.TopicRoute = Discourse.Route.extend({
   titleToken: function() {
     var model = this.modelFor('topic');
     if (model) {
-      return model.get('title');
+      var result = model.get('title'),
+          cat = model.get('category');
+
+      if (cat && !cat.get('isUncategorized')) {
+        var catName = cat.get('name'),
+            parentCategory = cat.get('parentCategory');
+
+        if (parentCategory) {
+          catName = parentCategory.get('name') + " / " + catName;
+        }
+
+        return [result, catName];
+      }
+      return result;
     }
   },