FIX: If a topic title edit fails, revert to previous title.

app/assets/javascripts/admin/models/admin_user.js

@@ -313,11 +313,11 @@ Discourse.AdminUser = Discourse.User.extend({
         } else {
           bootbox.alert(I18n.t("admin.user.delete_failed"));
           if (data.user) {
-            user.mergeAttributes(data.user);
+            user.setProperties(data.user);
           }
         }
       }, function() {
-        Discourse.AdminUser.find( user.get('username') ).then(function(u){ user.mergeAttributes(u); });
+        Discourse.AdminUser.find( user.get('username') ).then(function(u){ user.setProperties(u); });
         bootbox.alert(I18n.t("admin.user.delete_failed"));
       });
     };

app/assets/javascripts/admin/models/report.js

@@ -153,7 +153,7 @@ Discourse.Report.reopenClass({
           row.percentage = Math.round((row.y / maxY) * 100);
         });
       }
-      model.mergeAttributes(json.report);
+      model.setProperties(json.report);
       model.set('loaded', true);
     });
     return(model);

app/assets/javascripts/discourse/controllers/topic_controller.js

@@ -214,7 +214,7 @@ Discourse.TopicController = Discourse.ObjectController.extend(Discourse.Selected
         this.set('topicSaving', true);
 
         // manually update the titles & category
-        topic.setProperties({
+        var backup = topic.setPropertiesBackup({
           title: this.get('newTitle'),
           category_id: parseInt(this.get('newCategoryId'), 10),
           fancy_title: this.get('newTitle')
@@ -224,16 +224,11 @@ Discourse.TopicController = Discourse.ObjectController.extend(Discourse.Selected
         var self = this;
         topic.save().then(function(result){
           // update the title if it has been changed (cleaned up) server-side
-          var title       = result.basic_topic.title;
-          var fancy_title = result.basic_topic.fancy_title;
-          topic.setProperties({
-            title: title,
-            fancy_title: fancy_title
-          });
+          topic.setProperties(Em.getProperties(result.basic_topic, 'title', 'fancy_title'));
           self.set('topicSaving', false);
         }, function(error) {
-          self.set('editingTopic', true);
-          self.set('topicSaving', false);
+          self.setProperties({ editingTopic: true, topicSaving: false });
+          topic.setProperties(backup);
           if (error && error.responseText) {
             bootbox.alert($.parseJSON(error.responseText).errors[0]);
           } else {

app/assets/javascripts/discourse/models/model.js

@@ -1,40 +1,19 @@
-/**
-  A base object we can use to handle models in the Discourse client application.
-
-  @class Model
-  @extends Ember.Object
-  @uses Discourse.Presence
-  @namespace Discourse
-  @module Discourse
-**/
 Discourse.Model = Ember.Object.extend(Discourse.Presence, {
-
-  /**
-    Update our object from another object
-
-    @method mergeAttributes
-    @param {Object} attrs The attributes we want to merge with
-  **/
-  mergeAttributes: function(attrs) {
-    var self = this;
-    _.each(attrs, function(v, k) {
-      self.set(k, v);
-    });
+  // Like `setProperties` but returns the original values in case
+  // we want to roll back
+  setPropertiesBackup: function(obj) {
+    var backup = this.getProperties(Ember.keys(obj));
+    this.setProperties(obj);
+    return backup;
   }
 });
 
 Discourse.Model.reopenClass({
-
-  /**
-    Given an array of values, return them in a hash
-
-    @method extractByKey
-    @param {Object} collection The collection of values
-    @param {Object} klass The class to instantiate
-  **/
   extractByKey: function(collection, klass) {
     var retval = {};
-    _.each(collection, function(item) {
+    if (Ember.isEmpty(collection)) { return retval; }
+
+    collection.forEach(function(item) {
       retval[item.id] = klass.create(item);
     });
     return retval;

app/assets/javascripts/discourse/models/site.js

@@ -64,7 +64,7 @@ Discourse.Site = Discourse.Model.extend({
 
   updateCategory: function(newCategory) {
     var existingCategory = this.get('categories').findProperty('id', Em.get(newCategory, 'id'));
-    if (existingCategory) existingCategory.mergeAttributes(newCategory);
+    if (existingCategory) existingCategory.setProperties(newCategory);
   }
 });
 

test/javascripts/models/model_test.js

@@ -4,34 +4,6 @@ test("mixes in Discourse.Presence", function() {
   ok(Discourse.Presence.detect(Discourse.Model.create()));
 });
 
-test("mergeAttributes: merges attributes from another object", function() {
-  var model = Discourse.Model.create({
-    foo: "foo",
-    bar: "original bar"
-  });
-
-  model.mergeAttributes({
-    bar: "merged bar",
-    baz: "baz"
-  });
-
-  equal(model.get("foo"), "foo", "leaving original attr intact when only original object contains given key");
-  equal(model.get("bar"), "merged bar", "overwriting original attr when both objects contain given key");
-  equal(model.get("baz"), "baz", "adding new attr to original object when only merged object contains given key");
-});
-
-test("mergeAttributes: respects Ember setters (so observers etc. work)", function() {
-  var observerHasFired = false;
-
-  var model = Discourse.Model.create({foo: "original foo"});
-  model.addObserver("foo", function() {
-    observerHasFired = true;
-  });
-  model.mergeAttributes({foo: "merged foo"});
-
-  ok(observerHasFired);
-});
-
 test("extractByKey: converts a list of hashes into a hash of instances of specified class, indexed by their ids", function() {
   var firstObject = {id: "id_1", foo: "foo_1"};
   var secondObject = {id: "id_2", foo: "foo_2"};