Refactor app events to more efficiently handle post highlighting

app/assets/javascripts/discourse/initializers/inject-objects.js.es6

@@ -1,11 +1,12 @@
 import Session from 'discourse/models/session';
+import AppEvents from 'discourse/lib/app-events';
 
 export default {
   name: "inject-objects",
   initialize: function(container, application) {
 
     // Inject appEvents everywhere
-    var appEvents = Ember.Object.createWithMixins(Ember.Evented);
+    var appEvents = AppEvents.create();
     application.register('app-events:main', appEvents, { instantiate: false });
 
     application.inject('controller', 'appEvents', 'app-events:main');

app/assets/javascripts/discourse/lib/app-events.js.es6

@@ -0,0 +1,23 @@
+export default Ember.Object.extend(Ember.Evented);
+
+var id = 1;
+function newKey() {
+  return "_view_app_event_" + (id++);
+}
+
+export function createViewListener(eventName, cb) {
+  var extension = {};
+  extension[newKey()] = function() {
+    this.appEvents.on(eventName, this, cb);
+  }.on('didInsertElement');
+
+  extension[newKey()] = function() {
+    this.appEvents.off(eventName, this, cb);
+  }.on('willDestroyElement');
+
+  return extension;
+}
+
+export function listenForViewEvent(viewClass, eventName, cb) {
+  viewClass.reopen(createViewListener(eventName, cb));
+}

app/assets/javascripts/discourse/lib/url.js

@@ -2,7 +2,7 @@
 var jumpScheduled = false,
     rewrites = [];
 
-Discourse.URL = Em.Object.createWithMixins({
+Discourse.URL = Ember.Object.createWithMixins({
 
   // Used for matching a topic
   TOPIC_REGEXP: /\/t\/([^\/]+)\/(\d+)\/?(\d+)?/,
@@ -210,10 +210,10 @@ Discourse.URL = Em.Object.createWithMixins({
         if (path.match(/last$/)) { opts.nearPost = topicController.get('highest_post_number'); }
         var closest = opts.nearPost || 1;
 
+        var self = this;
         postStream.refresh(opts).then(function() {
           topicController.setProperties({
             currentPost: closest,
-            highlightOnInsert: closest,
             enteredAt: new Date().getTime().toString()
           });
           var closestPost = postStream.closestPostForPostNumber(closest),
@@ -221,7 +221,7 @@ Discourse.URL = Em.Object.createWithMixins({
               progressController = container.lookup('controller:topic-progress');
 
           progressController.set('progressPosition', progress);
-          Discourse.PostView.considerHighlighting(topicController, closest);
+          self.appEvents.trigger('post:highlight', closest);
         }).then(function() {
           Discourse.URL.jumpToPost(closest);
         });

app/assets/javascripts/discourse/mixins/url-refresh.js.es6

@@ -4,16 +4,9 @@
 //
 // This is useful if you want to get around Ember's default
 // behavior of not refreshing when navigating to the same place.
-export default Em.Mixin.create({
-  _initURLRefresh: function() {
-    this.appEvents.on('url:refresh', this, '_urlRefresh');
-  }.on('didInsertElement'),
 
-  _tearDownURLRefresh: function() {
-    this.appEvents.off('url:refresh', this, '_urlRefresh');
-  }.on('willDestroyElement'),
+import { createViewListener } from 'discourse/lib/app-events';
 
-  _urlRefresh: function() {
-    this.get('controller').send('refresh');
-  }
+export default createViewListener('url:refresh', function() {
+  this.get('controller').send('refresh');
 });

app/assets/javascripts/discourse/routes/topic-from-params.js.es6

@@ -1,5 +1,4 @@
 // This route is used for retrieving a topic based on params
-
 export default Discourse.Route.extend({
 
   setupController: function(controller, params) {
@@ -15,6 +14,7 @@ export default Discourse.Route.extend({
     // I sincerely hope no topic gets this many posts
     if (params.nearPost === "last") { params.nearPost = 999999999; }
 
+    var self = this;
     postStream.refresh(params).then(function () {
 
       // TODO we are seeing errors where closest post is null and this is exploding
@@ -28,13 +28,13 @@ export default Discourse.Route.extend({
       topicController.setProperties({
         currentPost: closest,
         enteredAt: new Date().getTime().toString(),
-        highlightOnInsert: closest
       });
 
       topicProgressController.setProperties({
         progressPosition: progress,
         expanded: false
       });
+      self.appEvents.trigger('post:highlight', closest);
       Discourse.URL.jumpToPost(closest);
 
       if (topic.present('draft')) {

app/assets/javascripts/discourse/views/post.js.es6

@@ -1,6 +1,6 @@
 var DAY = 60 * 50 * 1000;
 
-Discourse.PostView = Discourse.GroupedView.extend(Ember.Evented, {
+var PostView = Discourse.GroupedView.extend(Ember.Evented, {
   classNames: ['topic-post', 'clearfix'],
   templateName: 'post',
   classNameBindings: ['postTypeClass',
@@ -175,11 +175,7 @@ Discourse.PostView = Discourse.GroupedView.extend(Ember.Evented, {
   },
 
   actions: {
-    /**
-      Toggle the replies this post is a reply to
-
-      @method showReplyHistory
-    **/
+    // Toggle the replies this post is a reply to
     toggleReplyHistory: function(post) {
 
       var replyHistory = post.get('replyHistory'),
@@ -203,7 +199,7 @@ Discourse.PostView = Discourse.GroupedView.extend(Ember.Evented, {
         }
 
         Em.run.next(function() {
-          Discourse.PostView.highlight(replyPostNumber);
+          PostView.highlight(replyPostNumber);
           $(window).scrollTop(self.$().position().top - offsetFromTop);
         });
         return;
@@ -267,15 +263,7 @@ Discourse.PostView = Discourse.GroupedView.extend(Ember.Evented, {
 
     this._showLinkCounts();
 
-    // Track this post
     Discourse.ScreenTrack.current().track(this.$().prop('id'), postNumber);
-
-    // Highlight the post if required
-    if (postNumber > 1) {
-      Discourse.PostView.considerHighlighting(this.get('controller'), postNumber);
-    }
-
-    // Add syntax highlighting
     Discourse.SyntaxHighlighting.apply($post);
     Discourse.Lightbox.apply($post);
 
@@ -307,27 +295,4 @@ Discourse.PostView = Discourse.GroupedView.extend(Ember.Evented, {
   }.observes('controller.searchHighlight', 'cooked')
 });
 
-function highlight(postNumber) {
-  var $contents = $('#post_' + postNumber +' .topic-body'),
-      origColor = $contents.data('orig-color') || $contents.css('backgroundColor');
-
-  $contents.data("orig-color", origColor)
-    .addClass('highlighted')
-    .stop()
-    .animate({ backgroundColor: origColor }, 2500, 'swing', function(){
-      $contents.removeClass('highlighted');
-      $contents.css({'background-color': ''});
-    });
-}
-
-Discourse.PostView.reopenClass({
-  considerHighlighting: function(controller, postNumber) {
-    var highlightNumber = controller.get('highlightOnInsert');
-
-    // If we're meant to highlight a post
-    if (highlightNumber === postNumber) {
-      controller.set('highlightOnInsert', null);
-      Ember.run.scheduleOnce('afterRender', null, highlight, postNumber);
-    }
-  }
-});
+export default PostView;

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

@@ -1,6 +1,7 @@
 import AddCategoryClass from 'discourse/mixins/add-category-class';
+import { listenForViewEvent } from 'discourse/lib/app-events';
 
-export default Discourse.View.extend(AddCategoryClass, Discourse.Scrolling, {
+var TopicView = Discourse.View.extend(AddCategoryClass, Discourse.Scrolling, {
   templateName: 'topic',
   topicBinding: 'controller.model',
   userFiltersBinding: 'controller.userFilters',
@@ -157,3 +158,22 @@ export default Discourse.View.extend(AddCategoryClass, Discourse.Scrolling, {
     }
   }.property('topicTrackingState.messageCount')
 });
+
+function highlight(postNumber) {
+  var $contents = $('#post_' + postNumber +' .topic-body'),
+      origColor = $contents.data('orig-color') || $contents.css('backgroundColor');
+
+  $contents.data("orig-color", origColor)
+    .addClass('highlighted')
+    .stop()
+    .animate({ backgroundColor: origColor }, 2500, 'swing', function(){
+      $contents.removeClass('highlighted');
+      $contents.css({'background-color': ''});
+    });
+}
+
+listenForViewEvent(TopicView, 'post:highlight', function(postNumber) {
+  Ember.run.scheduleOnce('afterRender', null, highlight, postNumber);
+});
+
+export default TopicView;

app/assets/javascripts/main_include.js

@@ -10,6 +10,7 @@
 //
 
 // Stuff we need to load first
+//= require ./discourse/lib/app-events
 //= require ./discourse/helpers/i18n
 //= require ./discourse/lib/ember_compat_handlebars
 //= require ./discourse/lib/computed

plugins/poll/assets/javascripts/initializers/poll.js.es6

@@ -1,4 +1,5 @@
 import PollController from "discourse/plugins/poll/controllers/poll";
+import PostView from "discourse/views/post";
 
 var Poll = Discourse.Model.extend({
   post: null,
@@ -71,7 +72,7 @@ export default {
   name: 'poll',
 
   initialize: function() {
-    Discourse.PostView.reopen({
+    PostView.reopen({
       createPollUI: function($post) {
         var post = this.get('post');