rx_redux todo

main.dart

import 'package:flutter/material.dart';
import 'package:rx_redux/rx_redux.dart';
import 'package:rxdart/rxdart.dart';
import 'package:random_string/random_string.dart';

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

class MyApp extends StatelessWidget {
  @override
  Widget build(BuildContext context) {
    return MaterialApp(
      title: 'Flutter Demo',
      theme: ThemeData(primarySwatch: Colors.red),
      home: MyHomePage(),
    );
  }
}

class MyHomePage extends StatefulWidget {
  const MyHomePage({Key key}) : super(key: key);

  @override
  _MyHomePageState createState() => _MyHomePageState();
}

// actions

abstract class Action {}

class AddTodo implements Action {
  final Todo todo;

  AddTodo(this.todo);
}

class RemoveTodo implements Action {
  final Todo todo;

  RemoveTodo(this.todo);
}

class ToggleTodo implements Action {
  final Todo todo;

  ToggleTodo(this.todo);
}

class TodoAdded implements Action {
  final Todo todo;

  TodoAdded(this.todo);
}

class TodoRemoved implements Action {
  final Todo todo;

  TodoRemoved(this.todo);
}

class TodoToggled implements Action {
  final Todo todo;

  TodoToggled(this.todo);
}

// view state

class Todo {
  final int id;
  final String title;
  final bool completed;

  const Todo(this.id, this.title, this.completed);
}

class ViewState {
  final List<Todo> todos;

  const ViewState(this.todos);
}

class _MyHomePageState extends State<MyHomePage> {
  static var _id = 0;
  final actionS = PublishSubject<Action>();
  ValueObservable<ViewState> state$;

  @override
  void initState() {
    super.initState();

    const initialVS = ViewState([]);
    state$ = actionS
        .transform(
          ReduxStoreStreamTransformer<Action, ViewState>(
            initialStateSupplier: () => initialVS,
            reducer: (ViewState vs, Action action) {
              if (action is AddTodo) return vs;
              if (action is RemoveTodo) return vs;
              if (action is ToggleTodo) return vs;

              if (action is TodoAdded) {
                return ViewState([...vs.todos, action.todo]);
              }

              if (action is TodoRemoved) {
                return ViewState(
                  vs.todos.where((t) => t.id != action.todo.id).toList(),
                );
              }

              if (action is TodoToggled) {
                return ViewState(
                  vs.todos.map((t) {
                    if (t.id != action.todo.id) {
                      return t;
                    } else {
                      return Todo(
                        t.id,
                        t.title,
                        !t.completed,
                      );
                    }
                  }).toList(),
                );
              }

              return vs;
            },
            sideEffects: [
              (action$, state) {
                return action$
                    .whereType<AddTodo>()
                    .map((action) => action.todo)
                    .flatMap((todo) async* {
                  await Future.delayed(const Duration(milliseconds: 500));
                  yield TodoAdded(todo);
                });
              },
              (action$, state) {
                return action$
                    .whereType<RemoveTodo>()
                    .map((action) => action.todo)
                    .flatMap((todo) async* {
                  await Future.delayed(const Duration(milliseconds: 500));
                  yield TodoRemoved(todo);
                });
              },
              (action$, state) {
                return action$
                    .whereType<ToggleTodo>()
                    .map((action) => action.todo)
                    .flatMap((todo) async* {
                  await Future.delayed(const Duration(milliseconds: 500));
                  yield TodoToggled(todo);
                });
              },
            ],
          ),
        )
        .shareValueSeeded(initialVS);
  }

  @override
  void dispose() {
    super.dispose();
  }

  @override
  Widget build(BuildContext context) {
    return Scaffold(
      appBar: AppBar(
        title: Text('RxRedux demo'),
      ),
      body: StreamBuilder<ViewState>(
        initialData: state$.value,
        stream: state$,
        builder: (context, snapshot) {
          final todos = snapshot.data.todos;

          return ListView.builder(
            itemCount: todos.length,
            itemBuilder: (context, index) {
              final todo = todos[index];

              return CheckboxListTile(
                title: Text(todo.title),
                onChanged: (_) => actionS.add(ToggleTodo(todo)),
                value: todo.completed,
                secondary: IconButton(
                  icon: Icon(
                    Icons.delete,
                    color: Theme.of(context).accentColor,
                  ),
                  onPressed: () => actionS.add(RemoveTodo(todo)),
                ),
              );
            },
          );
        },
      ),
      floatingActionButton: FloatingActionButton(
        child: Icon(Icons.add),
        onPressed: () {
          actionS.add(
            AddTodo(
              Todo(
                ++_id,
                randomString(10),
                false,
              ),
            ),
          );
        },
      ),
    );
  }
}

pubspec.yaml

name: test_flutter
description: A new Flutter project.

# The following defines the version and build number for your application.
# A version number is three numbers separated by dots, like 1.2.43
# followed by an optional build number separated by a +.
# Both the version and the builder number may be overridden in flutter
# build by specifying --build-name and --build-number, respectively.
# In Android, build-name is used as versionName while build-number used as versionCode.
# Read more about Android versioning at https://developer.android.com/studio/publish/versioning
# In iOS, build-name is used as CFBundleShortVersionString while build-number used as CFBundleVersion.
# Read more about iOS versioning at
# https://developer.apple.com/library/archive/documentation/General/Reference/InfoPlistKeyReference/Articles/CoreFoundationKeys.html
version: 1.0.0+1

environment:
  sdk: ">=2.2.2 <3.0.0"

dependencies:
  flutter:
    sdk: flutter

  # The following adds the Cupertino Icons font to your application.
  # Use with the CupertinoIcons class for iOS style icons.
  cupertino_icons: ^0.1.2
  rx_redux: ^1.0.1
  rxdart: ^0.22.2
  random_string: ^1.1.0

dependency_overrides:
  meta: 1.1.6

dev_dependencies:
  flutter_test:
    sdk: flutter


# For information on the generic Dart part of this file, see the
# following page: https://dart.dev/tools/pub/pubspec

# The following section is specific to Flutter.
flutter:

  # The following line ensures that the Material Icons font is
  # included with your application, so that you can use the icons in
  # the material Icons class.
  uses-material-design: true

  # To add assets to your application, add an assets section, like this:
  # assets:
  #  - images/a_dot_burr.jpeg
  #  - images/a_dot_ham.jpeg

  # An image asset can refer to one or more resolution-specific "variants", see
  # https://flutter.dev/assets-and-images/#resolution-aware.

  # For details regarding adding assets from package dependencies, see
  # https://flutter.dev/assets-and-images/#from-packages

  # To add custom fonts to your application, add a fonts section here,
  # in this "flutter" section. Each entry in this list should have a
  # "family" key with the font family name, and a "fonts" key with a
  # list giving the asset and other descriptors for the font. For
  # example:
  # fonts:
  #   - family: Schyler
  #     fonts:
  #       - asset: fonts/Schyler-Regular.ttf
  #       - asset: fonts/Schyler-Italic.ttf
  #         style: italic
  #   - family: Trajan Pro
  #     fonts:
  #       - asset: fonts/TrajanPro.ttf
  #       - asset: fonts/TrajanPro_Bold.ttf
  #         weight: 700
  #
  # For details regarding fonts from package dependencies,
  # see https://flutter.dev/custom-fonts/#from-packages