Merge branch 'master' into 2226-deferUpdates-if-binding-2

README.md

@@ -1,6 +1,8 @@
+# Knockout
+
 **Knockout** is a JavaScript [MVVM](http://en.wikipedia.org/wiki/Model_View_ViewModel) (a modern variant of MVC) library that makes it easier to create rich, desktop-like user interfaces with JavaScript and HTML. It uses *observers* to make your UI automatically stay in sync with an underlying data model, along with a powerful and extensible set of *declarative bindings* to enable productive development.
 
-##Getting started
+## Getting started
 
 [![Join the chat at https://gitter.im/knockout/knockout](https://badges.gitter.im/Join%20Chat.svg)](https://gitter.im/knockout/knockout?utm_source=badge&utm_medium=badge&utm_campaign=pr-badge&utm_content=badge)
 
@@ -11,40 +13,47 @@ For more details, see
  * Documentation on [the project's website](http://knockoutjs.com/documentation/introduction.html)
  * Online examples at [http://knockoutjs.com/examples/](http://knockoutjs.com/examples/)
 
-##Downloading Knockout
+## Downloading Knockout
 
 You can [download released versions of Knockout](http://knockoutjs.com/downloads/) from the project's website.
 
 For Node.js developers, Knockout is also available from [npm](https://npmjs.org/) - just run `npm install knockout`.
 
-##Building Knockout from sources
+## Building Knockout from sources
 
 If you prefer to build the library yourself:
 
- 1. **Clone the repo from GitHub**
+1. **Clone the repo from GitHub**
 
-        git clone https://github.com/knockout/knockout.git
-        cd knockout
+   ```sh
+   git clone https://github.com/knockout/knockout.git
+   cd knockout
+   ```
 
- 2. **Acquire build dependencies.** Make sure you have [Node.js](http://nodejs.org/) installed on your workstation. This is only needed to _build_ Knockout from sources. Knockout itself has no dependency on Node.js once it is built (it works with any server technology or none). Now run:
+2. **Acquire build dependencies.**
 
-        npm install -g grunt-cli
-        npm install
+   Make sure you have [Node.js](http://nodejs.org/) installed on your workstation. This is only needed to _build_ Knockout from sources. Knockout itself has no dependency on Node.js once it is built (it works with any server technology or none). Now run:
 
-    The first `npm` command sets up the popular [Grunt](http://gruntjs.com/) build tool. You might need to run this command with `sudo` if you're on Linux or Mac OS X, or in an Administrator command prompt on Windows. The second `npm` command fetches the remaining build dependencies.
+   ```sh
+   npm install -g grunt-cli
+   npm install
+   ```
 
- 3. **Run the build tool**
+   The first `npm` command sets up the popular [Grunt](http://gruntjs.com/) build tool. You might need to run this command with `sudo` if you're on Linux or Mac OS X, or in an Administrator command prompt on Windows. The second `npm` command fetches the remaining build dependencies.
 
-        grunt
+3. **Run the build tool**
 
-    Now you'll find the built files in `build/output/`.
+   ```sh
+   grunt
+   ```
+   Now you'll find the built files in `build/output/`.
 
 ## Running the tests
 
 If you have [phantomjs](http://phantomjs.org/download.html) installed, then the `grunt` script will automatically run the specification suite and report its results.
 
 Or, if you want to run the specs in a browser (e.g., for debugging), simply open `spec/runner.html` in your browser.
 
-##License
+## License
 
 MIT license - [http://www.opensource.org/licenses/mit-license.php](http://www.opensource.org/licenses/mit-license.php)

spec/asyncBehaviors.js

@@ -1209,5 +1209,33 @@ describe('Deferred', function() {
                 expect(threeNotifications).toEqual([true, false]);
             }
         });
+
+        it('Should only notify changes if computed was evaluated', function() {
+            // See https://github.com/knockout/knockout/issues/2240
+            // Set up a scenario where a computed will be marked as dirty but won't get marked as
+            // stale and so won't be re-evaluated
+            this.restoreAfter(ko.options, 'deferUpdates');
+            ko.options.deferUpdates = true;
+
+            var obs = ko.observable('somevalue'),
+                isTruthy = ko.pureComputed(function() { return !!obs(); }),
+                objIfTruthy = ko.pureComputed(function() { return isTruthy(); }).extend({ notify: 'always' }),
+                notifySpy = jasmine.createSpy('callback'),
+                subscription = objIfTruthy.subscribe(notifySpy);
+
+            obs('someothervalue');
+            jasmine.Clock.tick(1);
+            expect(notifySpy).not.toHaveBeenCalled();
+
+            obs('');
+            jasmine.Clock.tick(1);
+            expect(notifySpy).toHaveBeenCalled();
+            expect(notifySpy.argsForCall).toEqual([[false]]);
+            notifySpy.reset();
+
+            obs(undefined);
+            jasmine.Clock.tick(1);
+            expect(notifySpy).not.toHaveBeenCalled();
+        });
     });
 });

src/subscribables/dependentObservable.js

@@ -317,6 +317,9 @@ var computedFn = {
             if (!state.isSleeping && notifyChange) {
                 computedObservable["notifySubscribers"](state.latestValue);
             }
+            if (computedObservable._recordUpdate) {
+                computedObservable._recordUpdate();
+            }
         }
 
         if (isInitial) {
@@ -376,7 +379,7 @@ var computedFn = {
 
             // Pass the observable to the "limit" code, which will evaluate it when
             // it's time to do the notification.
-            this._limitChange(this);
+            this._limitChange(this, !isChange /* isDirty */);
         };
     },
     dispose: function () {

src/subscribables/subscribable.js

@@ -92,7 +92,8 @@ var ko_subscribable_fn = {
 
     limit: function(limitFunction) {
         var self = this, selfIsObservable = ko.isObservable(self),
-            ignoreBeforeChange, notifyNextChange, previousValue, pendingValue, beforeChange = 'beforeChange';
+            ignoreBeforeChange, notifyNextChange, previousValue, pendingValue, didUpdate,
+            beforeChange = 'beforeChange';
 
         if (!self._origNotifySubscribers) {
             self._origNotifySubscribers = self["notifySubscribers"];
@@ -107,16 +108,19 @@ var ko_subscribable_fn = {
             if (selfIsObservable && pendingValue === self) {
                 pendingValue = self._evalIfChanged ? self._evalIfChanged() : self();
             }
-            var shouldNotify = notifyNextChange || self.isDifferent(previousValue, pendingValue);
+            var shouldNotify = notifyNextChange || (didUpdate && self.isDifferent(previousValue, pendingValue));
 
-            notifyNextChange = ignoreBeforeChange = false;
+            didUpdate = notifyNextChange = ignoreBeforeChange = false;
 
             if (shouldNotify) {
                 self._origNotifySubscribers(previousValue = pendingValue);
             }
         });
 
-        self._limitChange = function(value) {
+        self._limitChange = function(value, isDirty) {
+            if (!isDirty || !self._notificationIsPending) {
+                didUpdate = !isDirty;
+            }
             self._changeSubscriptions = self._subscriptions[defaultEvent].slice(0);
             self._notificationIsPending = ignoreBeforeChange = true;
             pendingValue = value;
@@ -128,6 +132,9 @@ var ko_subscribable_fn = {
                 self._origNotifySubscribers(value, beforeChange);
             }
         };
+        self._recordUpdate = function() {
+            didUpdate = true;
+        };
         self._notifyNextChangeIfValueIsDifferent = function() {
             if (self.isDifferent(previousValue, self.peek(true /*evaluate*/))) {
                 notifyNextChange = true;