observeValueForKeyPath: called for every property, not just the observed property
How to observe array property changes in RxSwift
Receive KVO notifications for all property and changes recursively at top level
what to do when a variable is not KVO-compliant?
What's a good way to make a one-shot KVO observation?
Test if NSObject is observing string
Mocking an object under observation
Best practices for context parameter in addObserver (KVO)
sproutcore - observing array items properties
How to observe the value of an NSTextField
Why does NSOperation disable automatic key-value observing?