example of pure widgets in flutter

pureFlutterExample.dart

import 'package:flutter/material.dart';
import 'package:flutter_redux/flutter_redux.dart';
import 'package:redux/redux.dart';

void main() => runApp(ExampleApp());

// <framework-specific part>
typedef MetaBuilder<ViewModel> = Widget Function(ViewModelBuilder<ViewModel>);
int counterReducer(int state, dynamic action) =>
    state + (action is int ? action : 0);
Store<int> store = Store<int>(counterReducer, initialState: 0);
Widget counterConnector(ViewModelBuilder<int> builder) =>
    StoreConnector<int, int>(
      builder: builder,
      converter: (store) => store.state,
      distinct: true,
    );
void increment() => store.dispatch(1);
Widget provideStore(Widget child) => StoreProvider(store: store, child: child);
// </framework-specific part>

class ExampleApp extends StatelessWidget {
  @override
  Widget build(BuildContext context) => provideStore(MaterialApp(
        title: 'Flutter Demo',
        theme: ThemeData(
          primarySwatch: Colors.blue,
        ),
        initialRoute: "/",
        routes: {
          "/": (context) => HomePage(),
        },
      ));
}

class HomePage extends StatelessWidget {
  @override
  Widget build(BuildContext context) => Scaffold(
      floatingActionButton: FloatingActionButton(
        onPressed: increment,
        child: Icon(Icons.add),
      ),
      // here we bind Widget with connectors much like in React
      body:
          Center(child: CounterWidget<int>(counterBuilder: counterConnector)));
}

// framework-agnostic widget that does not use streams and can repaint partially
// it even can accept anything as counter
class CounterWidget<ViewModel> extends StatelessWidget {
  /// see [Builder] as example
  final MetaBuilder<ViewModel> counterBuilder;

  const CounterWidget({Key key, this.counterBuilder}) : super(key: key);

  @override
  Widget build(BuildContext context) =>
      Column(mainAxisAlignment: MainAxisAlignment.spaceEvenly, children: [
        Text('This text will not be repaint'),
        counterBuilder((context, counter) => Text('clicked $counter times')),
        Text('And we don\'t use streams'),
      ]);
}