shared_preferences_riverpod_new 0.2.0

shared_preferences_riverpod_new: ^0.2.0 copied to clipboard

example/lib/main.dart

import 'package:flutter/material.dart';
import 'package:flutter_riverpod/flutter_riverpod.dart';
import 'package:shared_preferences/shared_preferences.dart';
import 'package:shared_preferences_riverpod_new/shared_preferences_riverpod_new.dart';

/// A persisted flag, in one line. `ref.watch` gives you `bool`, not
/// `AsyncValue<bool>`.
final darkModeProvider = syncPrefProvider<bool>('settings.dark_mode', false);

/// A persisted int, clamped on both read and write.
final fontSizeProvider = syncPrefProvider<int>(
  'settings.font_size',
  14,
  normalize: (v) => v.clamp(10, 24),
);

/// A preference that owns a rule: show the hint at most [HintShows.maxShows]
/// times, ever. Subclass the notifier when a preference needs its own methods.
class HintShows extends SyncPrefNotifier<int> {
  HintShows() : super('settings.hint_shows', 0);

  static const int maxShows = 3;

  /// Whether the hint may be shown once more. Returns true after the bumped
  /// count has been persisted.
  Future<bool> tryConsume() async {
    if (state >= maxShows) return false;
    await set(state + 1);
    return true;
  }
}

final hintShowsProvider = NotifierProvider<HintShows, int>(
  HintShows.new,
  name: 'hintShows',
);

Future<void> main() async {
  WidgetsFlutterBinding.ensureInitialized();
  // Load once, before the first widget builds. Everything below is then a
  // plain synchronous read — no loading state to spell out at every call site.
  registerSyncPrefs(await SharedPreferences.getInstance());
  runApp(const ProviderScope(child: ExampleApp()));
}

class ExampleApp extends ConsumerWidget {
  const ExampleApp({super.key});

  @override
  Widget build(BuildContext context, WidgetRef ref) {
    final dark = ref.watch(darkModeProvider);
    final fontSize = ref.watch(fontSizeProvider);

    return MaterialApp(
      theme: ThemeData(brightness: dark ? Brightness.dark : Brightness.light),
      home: Scaffold(
        appBar: AppBar(title: const Text('Preferences')),
        body: ListView(
          children: [
            SwitchListTile(
              title: const Text('Dark mode'),
              subtitle: const Text('Survives relaunch'),
              value: dark,
              onChanged: (v) => ref.read(darkModeProvider.notifier).set(v),
            ),
            ListTile(
              title: Text(
                'Font size: $fontSize',
                style: TextStyle(fontSize: fontSize.toDouble()),
              ),
              subtitle: const Text('Clamped to 10..24 on read and write'),
              trailing: Row(
                mainAxisSize: MainAxisSize.min,
                children: [
                  IconButton(
                    icon: const Icon(Icons.remove),
                    onPressed: () =>
                        ref.read(fontSizeProvider.notifier).set(fontSize - 2),
                  ),
                  IconButton(
                    icon: const Icon(Icons.add),
                    onPressed: () =>
                        ref.read(fontSizeProvider.notifier).set(fontSize + 2),
                  ),
                ],
              ),
            ),
            ListTile(
              title: Text(
                'Hint shown ${ref.watch(hintShowsProvider)}'
                ' / ${HintShows.maxShows} times',
              ),
              subtitle: const Text('Tap to consume one show'),
              onTap: () async {
                final allowed =
                    await ref.read(hintShowsProvider.notifier).tryConsume();
                if (!context.mounted) return;
                ScaffoldMessenger.of(context).showSnackBar(
                  SnackBar(
                    content:
                        Text(allowed ? 'Here is the hint' : 'No more hints'),
                  ),
                );
              },
            ),
          ],
        ),
      ),
    );
  }
}