Is StateNotifierProvider only for when you update the UI?

Question

In Riverpod, if you have a class that has dynamic state, but you don't need to display changes to the state in the UI, do you use a StateNotifierProvider or just a plain Provider? Because StateNotifierProvider provides a hook to update the state of the class. What about if we manually update the state of a plain Provider, like:

final personProvider = Provider<Person>((provider) {
  final person = Person(name: 'Bob');
  return person;
});

Then elsewhere we update its state:

ref.read(personProvider) = Person(name: 'Joe');

Then elsewhere we rely on that state but do not display it in the UI:

// Will this be Bob, or Joe?
final dataToSaveToDatabase = ref.watch(personProvider);

Will Riverpod keep track of the state changes over time, such that if somewhere else in the app accesses said state with watch or read, it always gets the latest state?

Another way to frame this question is, "Is a StateNotifierProvider only used if you need to update the UI?"

The thing is, your code doesn't compile. You can't do `ref.read(personProvider) = Person(name: 'Joe');` — Rémi Rousselet, Oct 28 '22 at 16:39
@RémiRousselet Sorry. What about if it was something compilable like `ref.read(personProvider).hobby = 'surfing'`? — BeniaminoBaggins, Oct 28 '22 at 16:43
That's not going to do anything. You need a proper notification mechanism, be it StateNotifier, ChangeNotifier or whatever — Rémi Rousselet, Oct 28 '22 at 17:11
@RémiRousselet Okay, so just use one of the "notifier" providers if the state needs to be manually updated, even if we don't need to rebuild the UI. That makes sense. Thanks. — BeniaminoBaggins, Oct 28 '22 at 17:20

Is StateNotifierProvider only for when you update the UI?

0 Answers0