Add UserDefaultsMonitor

[eBardX]

Feature Name

• UserDefaultsMonitor -- should live in Foundation folder

Events

• didChange(UserDefaults) -- wraps UserDefaults.didChangeNotification notification
• sizeLimitExceeded -- wraps UserDefaults.sizeLimitExceededNotification notification

Platform

iOS/macOS/tvOS/watchOS

[eBardX]

@Descartess
Note: didChange(UserDefaults) looks to be very straightforward. The notifications wrapped by the other four events have vague documentation. It is not clear to me how those notifications are even generated in normal usage.

[Descartess]

@eBardX I am wondering what is the notification object for the other four events besides didChange(UserDefaults)

[eBardX]

My guess is that it would be an instance of UserDefaults in all cases. But I have no empirical evidence to back that up (yet).

[eBardX]

@Descartess
I’m thinking it may sense to break this into two separate monitors: UserDefaultsMonitor and UbiquitousUserDefaultsMonitor. If you look at the Objective-C names of the notifications, you’ll find that 2 are prefixed with NSUserDefaults* and 3 are prefixed with NSUbiquitousUserDefaults*. Also note that only 1 notification is supported on macOS. No matter how you slice it, on macOS it makes no sense to have an options parameter. This will make for some ugly code, although perhaps slightly less ugly if we opt for 2 monitors instead of 1. What do you think?

[Descartess]

Yes, that is correct. Let me create a separate issue for that