When you change the top level object, observer MUST receive value
for the key path of the previous top level object as old and
value for the key path of the new top level object as new.
- Moved common CPArray/CPSet collection KVC operators to _CPCollectionKVCOperators.
- Implemented KVC operator dispatch using Objective-J.
- Fixed infinite loop with empty collection in @min, @max and @sum operators.
- Correctly return valueForUndefinedKey when necessary.
- valueForUndefinedKey reason uses raw description for consistency, class' overridden description may not helpful at all.
- Don't create a forwarder for @ operators with property paths.
- Fixed CPSet -valueForKeyPath to correctly deal with nil/undefined/empty values.
- Added tests for collection KVC operators.
- enumerator -nextObject should always compare against nil for clarity, correctness, and consistency.
When multiple calls are nested, only the first willChange… and the last didChange… will notify observers, avoiding duplicate notifications for the same change.
Before this commit we would fail gracefully for single keys. For key paths an application would crash because we would try to get the forwarder property of an undefined object. This commit makes sure we don't attempt any removal and logs a warning (just like Cocoa) about the attempt to remove an unregistered observer.
1. Added class_getInstanceVariable to runtime.
2. Changed KVC to rely on class-defined variables vs prototypal ones.
3. Modified KVO code to use public APIs.
Reviewed by me.
During the "normal" callback for new and old values, the ofObject:
parameter passed to the observer is the original receiver of the
addObserver:forKeyPath:options:context: call, but that isn't the case
with the call caused by the CPKeyValueObservingOptionInitial option.
This commit uses _targetObject, the receiver of the addObserver:...
call, rather than self, the _CPKVOProxy.
It is crucial that we send notification only before and after complete changes. In the middle notifications might cause observers to see or react to inconsistent data (e.g. selection indexes pointing to rows no longer present). Added some unit tests - more might be needed in the future. Fixed: before and after values when observing array controller key paths during content changes or rearranges were wrong. Fixed: the array controller sent out multiple redundant change notifications.
