What is purpose of ChangeNotifierProvider.autoDispose in a riverpod flutter and how to use it?

ChangeNotifierProvider.autoDispose is a variant of ChangeNotifierProvider provided by the Riverpod state management library in Flutter. It is used to create a provider for a ChangeNotifier that automatically disposes of its value when no longer needed.

Here’s the purpose and usage of ChangeNotifierProvider.autoDispose:

1. Automatic Disposal: When you use ChangeNotifierProvider.autoDispose, the ChangeNotifier provided by this provider will automatically be disposed of when it is no longer being listened to. This can help prevent memory leaks in your application by cleaning up resources when they are no longer needed.
2. Scoped Lifetime: ChangeNotifierProvider.autoDispose creates a provider with a scoped lifetime. This means that the provided ChangeNotifier instance is tied to the widget subtree where it is used. When the widget subtree is disposed of (e.g., when the widget is removed from the widget tree), the ChangeNotifier instance will be automatically disposed of as well.
3. Efficient Resource Management: Using ChangeNotifierProvider.autoDispose can be particularly useful for managing resources that are tied to the lifetime of a widget subtree. For example, if you have a ChangeNotifier that fetches data from a network or database, using ChangeNotifierProvider.autoDispose ensures that the resources associated with the ChangeNotifier are released when the widget subtree is no longer needed.

Here’s an example of how to use ChangeNotifierProvider.autoDispose:

final myChangeNotifierProvider = ChangeNotifierProvider.autoDispose((ref) {
  return MyChangeNotifier(); // Create your ChangeNotifier instance
});

class MyWidget extends ConsumerWidget {
  @override
  Widget build(BuildContext context, ScopedReader watch) {
    final myChangeNotifier = watch(myChangeNotifierProvider);

    // Use myChangeNotifier in your widget build method
    return ...
  }
}

In this example:

• ChangeNotifierProvider.autoDispose creates a provider for a ChangeNotifier instance.

• The MyWidget widget consumes the ChangeNotifier using the watch method and rebuilds itself when the ChangeNotifier changes.

• When MyWidget is disposed of (e.g., removed from the widget tree), the ChangeNotifier provided by ChangeNotifierProvider.autoDispose will be automatically disposed of as well.