Jonathon Mah: If user defaults can change separately from this code (and you should probably assume it can), providing correct KVO change notifications can be accomplished by having the singleton observe NSUserDefaults with NSKeyValueObservingOptionPrior; posting willChangeValueForKey:@”mySetting” on the prior callback and didChangeValueForKey:@”mySetting” on the post callback. But this sucks — it’s wordy and you pay … Continue reading Dependent Key Paths