Riverpod — ProviderObservers
Instructions
A ProviderObserver receives lifecycle events for providers (e.g. when a provider's value changes). Use it for logging, analytics, or debugging.
Implementing an observer
Extend ProviderObserver and override the methods you need (e.g. didUpdateProvider). Pass instances to ProviderScope or ProviderContainer via the observers parameter.
Example: logger
final class Logger extends ProviderObserver {
@override
void didUpdateProvider(
ProviderObserverContext context,
Object? previousValue,
Object? newValue,
) {
print('{"provider": "${context.provider}", "newValue": "$newValue"}');
}
}
void main() {
runApp(
ProviderScope(
observers: [Logger()],
child: const MyApp(),
),
);
}Naming providers
For clearer logs, give providers a name:
final myProvider = Provider<int>((ref) => 0, name: 'MyProvider');With code generation, a name is usually assigned automatically.
Note on mutations
If state is mutated in place (e.g. a List with ref.notifyListeners), previousValue and newValue in didUpdateProvider may be the same reference. For distinct values, clone before mutating.