majiayu000 Riverpod — Pull-to-refresh
Instructions
Riverpod fits pull-to-refresh well: refresh by invalidating the provider and let AsyncValue handle loading vs data vs error.
1. Provider and UI
Define an async provider (e.g. FutureProvider or AsyncNotifierProvider) that fetches data. Display it with ref.watch(provider) so you get an AsyncValue.
2. RefreshIndicator
Wrap your scrollable (ListView, SingleChildScrollView, etc.) in RefreshIndicator. In onRefresh, call ref.refresh(provider.future) so the indicator stays until the new data is loaded:
RefreshIndicator(
onRefresh: () => ref.refresh(activityProvider.future),
child: ListView(
children: [
// content
],
),
)
3. Loading and error states
Use AsyncValue pattern matching:
- Initial load: No data and no error → show full-screen spinner.
- Refresh: Show the refresh indicator and keep showing previous data (or previous error) until the new result arrives.
- Data:
AsyncValue(:final value?)or similar to show the value. - Error:
AsyncValue(:final error?)to show the error.
Example (syntax may vary by Riverpod version):
final activity = ref.watch(activityProvider);
switch (activity) {
AsyncValue<Activity>(:final value?) => Text(value.activity),
AsyncValue(:final error?) => Text('Error: $error'),
_ => const CircularProgressIndicator(),
}
Use valueOrNull (or equivalent) if your API exposes it for nullable data. See the docs for the exact AsyncValue API in your version.