riverpod-ref-in-provider-lifecycle

Riverpod ref Usage in Provider Lifecycle Callbacks

Problem

When using ref.keepAlive() with timer-based auto-disposal in @riverpod providers, async callbacks (.then(), .catchError()) that execute during or after disposal will crash when they try to use ref.read(), ref.invalidateSelf(), or any other ref operation.

Context / Trigger Conditions

Error message:

'package:riverpod/src/core/ref.dart': Failed assertion: line 216 pos 7:
'_debugCallbackStack == 0': Cannot use Ref or modify other providers inside life-cycles/selectors.

Typical scenario:

1. Provider uses ref.keepAlive() with a timer in ref.onCancel():

final link = ref.keepAlive();
ref.onCancel(() {
  Timer(Duration(seconds: 15), () {
    link.close();  // Triggers disposal
  });
});

1. Provider has async callbacks that use ref:

someAsyncOperation().then((_) {
  if (ref.mounted) {  // THIS CHECK IS NOT ENOUGH!
    ref.invalidateSelf();
  }
});

1. Timer fires while async callback is pending
2. CRASH - ref.mounted returns true but using ref is still forbidden

Key insight: ref.mounted returns true during lifecycle callbacks, but using ref operations is still forbidden. This is counter-intuitive but by design.

Solution

Option 1: Wrap ref operations in try-catch (Recommended)

someAsyncOperation().then((_) {
  try {
    ref.read(someProvider.notifier).update(/*...*/);
  } catch (e) {
    Log.debug('Provider likely disposed: $e');
  }
});

Option 2: Avoid ref operations in async callbacks entirely

Instead of:

// BAD - uses ref in async callback
openVineVideoCache.removeCorruptedVideo(videoId).then((_) {
  if (ref.mounted) {
    ref.invalidateSelf();  // CRASH!
  }
});

Do:

// GOOD - fire-and-forget without ref
unawaited(
  openVineVideoCache.removeCorruptedVideo(videoId).then((_) {
    Log.info('Cache removed');  // No ref usage
  }),
);
// Let user retry manually or provider recreates on next access