autoDispose modifier in riverpod

Question

I have multiple values (in class) in provider and when I use the autoDispose modifier in provider then I want to dispose of only a few values in the provider is it possible to do like this?

I have searched for this on the internet but I didn't find any resources related to this requirement.

final provider = StateProvider((ref) => LoginDetails(
      errorMessage: '', status: 0));

class LoginDetails {
  int status;
  String errorMessage;
  LoginDetails({
    required this.status,
    required this.errorMessage,
  });

  LoginDetails copyWith({
    int? status,
    String? errorMessage,
  }) =>
      LoginDetails(
        status: status ?? this.status,
        errorMessage: errorMessage ?? this.errorMessage,
      );
}

Answer 1

There is no way to have autoDispose only dispose a few property. autoDispose is all or nothing

On the other hand, using version 2.0.0-dev, you can use ref.onCancel to perform some logic when the last listener is removed – which is available even on providers that are not autoDispose

So you can do:

final provider = Provider((ref) {
  ref.onCancel(() {
    // TODO reset the few properties of your choice
  });

  return SomeState();
});

Answer 2

I know two ways to do that

The first way is to make the variables private static

  static int _status = 0;
  
  // You can access it outside the Provider class by using getter
  int get status => _status;

The second way is to have another provider that contains the needed information which you don't want to lose, and I prefer this way.

and still I am sure there is many alternative solutions out there but it's all depends on your use case.