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riverpod example in flutter - perfect to start project from

The Biton answered on June 23, 2024 Popularity 1/10 Helpfulness 1/10

answer riverpod example in flutter - perfect to start project from

riverpod example in flutter - perfect to start project from

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

void main() {
  runApp(ProviderScope(child: MyApp()));
}

final userProvider = StateNotifierProvider<HomeNotifier, HomeState?>((ref) {
  return HomeNotifier(ref);
});

class HomeNotifier extends StateNotifier<HomeState?> {
  Ref ref;
  int actionCount = 0;

  HomeNotifier(this.ref) : super(HomeState());

  void _getBasicNotifierState() {
    final basicState = ref.read(basicProvider);
    print('XX -> ${basicState?.num}');
  }

  void setUser(HomeState user) {
    state = user; // init-state user with ConsumerStatefulWidget()
    _incrementActionCount();
  }

  void updateName(String newName) {
    _getBasicNotifierState();
    if (state != null) {
      state = state!.copyWith(name: newName);
      _incrementActionCount();
    }
  }

  void incrementAge() {
    _getBasicNotifierState();
    if (state != null) {
      state = state!.copyWith(age: state!.age + 1);
      _incrementActionCount();
    }
  }

  void _incrementActionCount() {
    actionCount++;
    print('Action Count: $actionCount');
  }
}

/// Todo: try build as Freezed model!
class HomeState {
  final String? name;
  final int age;

  HomeState({
    this.name,
    this.age = 0,
  });

  HomeState copyWith({String? name, int? age}) {
    return HomeState(
      name: name ?? this.name,
      age: age ?? this.age,
    );
  }
}

class MyApp extends StatelessWidget {
  @override
  Widget build(BuildContext context) {
    return MaterialApp(
      home: Scaffold(
        appBar: AppBar(title: Text('User State Notifier Example')),
        body: const Center(
          child: HomeScreen(),
        ),
      ),
    );
  }
}

// class HomeScreen extends ConsumerStatefulWidget {
class HomeScreen extends ConsumerWidget {
  const HomeScreen({super.key});

// @override
// _HomeScreenState createState() => _HomeScreenState();
// }
//
// class _HomeScreenState extends ConsumerState<HomeScreen> {
//   @override
//   void initState() {
//     super.initState();
//     Future.microtask(() =>
//         ref.read(userProvider.notifier).setUser(HomeState(name: "John Doe", age: 30))
//     );
//   }

  @override
  Widget build(BuildContext context, WidgetRef ref) {
    final userModel = ref.read(userProvider.notifier);
    final userState = ref.watch(userProvider);

    return Column(
      mainAxisAlignment: MainAxisAlignment.center,
      children: <Widget>[
        if (userState != null)
          Text('Name: ${userState.name}, Age: ${userState.age}'),
        Text('Action Count: ${userModel.actionCount}'),
        ElevatedButton(
          onPressed: () => userModel.updateName("Jane Doe"),
          child: Text('Set Jane Doe'),
        ),
        ElevatedButton(
          onPressed: () => userModel.incrementAge(),
          child: Text('Age++'),
        ),
      ],
    );
  }
}

final basicProvider = StateNotifierProvider<BasicNotifier, BasicState?>((ref) {
  return BasicNotifier();
});

class BasicNotifier extends StateNotifier<BasicState?> {
  BasicNotifier() : super(BasicState());
// Void actions here
}

class BasicState {
  final int num;
  BasicState({this.num = 2});
  BasicState copyWith({int? num}) {
    return BasicState(num: num ?? this.num);
  }
}

Popularity 1/10 Helpfulness 1/10 Language dart

Source: Grepper

Tags: dart flutter perfect project riverpod

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Contributed on Jun 23 2024

The Biton

0 Answers Avg Quality 2/10

riverpod example in flutter - perfect to start project from

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