refena 2.0.0-dev.0

A state management library for Dart and Flutter. Inspired by Riverpod and async_redux.

example/lib/main.dart

import 'package:flutter/foundation.dart';
import 'package:flutter/material.dart';
import 'package:refena_flutter/refena_flutter.dart';

final numberProvider = Provider<int>((ref) => throw 'Not initialized');

final counterProviderA = NotifierProvider<Counter, int>((ref) => Counter());

final counterProviderB = NotifierProvider<Counter, int>((ref) => Counter());

class Counter extends Notifier<int> {
  @override
  int init() => 10;

  void increment() {
    int a = ref.read(numberProvider);
    print('Reading another provider: $a');
    state++;
  }
}

void main() {
  runApp(
    RefenaScope(
      overrides: [
        numberProvider.overrideWithValue(999),
      ],
      observers: [
        if (kDebugMode) RefenaDebugObserver(),
      ],
      child: const MyApp(),
    ),
  );
}

class MyApp extends StatelessWidget {
  const MyApp({super.key});

  @override
  Widget build(BuildContext context) {
    return const MaterialApp(
      title: 'Flutter Demo',
      home: HomePage(),
    );
  }
}

class HomePage extends StatefulWidget {
  const HomePage({super.key});

  @override
  State<HomePage> createState() => _HomePageState();
}

class _HomePageState extends State<HomePage> with Refena {
  @override
  Widget build(BuildContext context) {
    final myNumber = ref.watch(numberProvider);
    final myCounter = ref.watch(counterProviderA);
    return Scaffold(
      body: Column(
        children: [
          Text('The number is $myNumber'),
          Text('The counter is $myCounter'),
          ElevatedButton(
            onPressed: () {
              ref.notifier(counterProviderA).increment();
            },
            child: const Text('+ 1'),
          ),
          ElevatedButton(
            onPressed: () {
              Navigator.of(context).push(MaterialPageRoute(
                  builder: (context) => const MySecondPage()));
            },
            child: const Text('Open second page'),
          ),
        ],
      ),
    );
  }
}

class MySecondPage extends StatelessWidget {
  const MySecondPage({super.key});

  @override
  Widget build(BuildContext context) {
    return Scaffold(
      appBar: AppBar(
        title: const Text('Second page'),
      ),
      body: Row(
        children: [
          Expanded(
            child: Consumer(
              debugLabel: 'Consumer A',
              builder: (context, ref) {
                final myCounter = ref.watch(
                  counterProviderA,
                  listener: (prev, next) {
                    print('Listener event of Counter A: $prev -> $next');
                  },
                  rebuildWhen: (prev, next) => next % 2 == 0,
                );
                print('Rebuild A');
                return Column(
                  children: [
                    Text('Counter A $myCounter'),
                    ElevatedButton(
                      onPressed: () {
                        ref.notifier(counterProviderA).increment();
                      },
                      child: const Text('+ 1'),
                    ),
                  ],
                );
              },
            ),
          ),
          Expanded(
            child: Consumer(
              debugLabel: 'Consumer B',
              builder: (context, ref) {
                final anotherCounter = ref.watch(
                  counterProviderB,
                  listener: (prev, next) {
                    print('Listener event of Counter B: $prev -> $next');
                  },
                );
                print('Rebuild B');
                return Column(
                  children: [
                    Text('Counter B $anotherCounter'),
                    ElevatedButton(
                      onPressed: () {
                        // Calling twice should be ok, rebuilds only once
                        ref.notifier(counterProviderB).increment();
                        ref.notifier(counterProviderB).increment();
                      },
                      child: const Text('+ 1'),
                    ),
                  ],
                );
              },
            ),
          ),
        ],
      ),
    );
  }
}