favour_state package

State management solution for flutter inspired by cerebraljs and property_change_notifier

Documentation now in WIP status. Please look at example.

#Example

// store.dart

import 'dart:async';

import 'package:favour_state/favour_state.dart';

import 'state.dart';

class ExampleStore extends Store<ExampleState> {
  // you can initialize your state

  Future<void> multiply(int multiplier) async {
    this(MultiplyOperation(2));
  }

  void toggle() {
    this[#enabled] = !state.enabled;
  }

  @override
  ExampleState get initialState => const ExampleState(enabled: false);
}

class MultiplyOperation extends Operation<ExampleStore> {
  final int multiplier;

  MultiplyOperation(this.multiplier);

  @override
  FutureOr<void> call(ExampleStore store) async {
    store[#counter] = 0;
    while (store.state.counter < 1000) {
      store[#counter] = store.state.counter + multiplier;
      await Future.delayed(const Duration(milliseconds: 1), () {});
    }
  }

  @override
  String get topic => 'multiply';
}

// state.dart

import 'package:favour_state/favour_state.dart';
import 'package:flutter/foundation.dart';

@immutable
class ExampleState implements StoreState<ExampleState> {
  final int counter;
  final bool enabled;

  const ExampleState({
    this.counter = 1,
    this.enabled = true,
  });

  @override
  ExampleState copyWith({
    int counter,
    bool enabled,
  }) {
    if ((counter == null || identical(counter, this.counter)) &&
        (enabled == null || identical(enabled, this.enabled))) {
      return this;
    }

    return ExampleState(
      counter: counter ?? this.counter,
      enabled: enabled ?? this.enabled,
    );
  }

  @override
  bool operator ==(Object other) =>
      identical(this, other) ||
      other is ExampleState &&
          runtimeType == other.runtimeType &&
          counter == other.counter &&
          enabled == other.enabled;

  @override
  int get hashCode => counter.hashCode ^ enabled.hashCode;

  @override
  String toString() => 'ExampleState{counter: $counter, enabled: $enabled}';
}

// main.dart
import 'package:favour_state/favour_state.dart';
import 'package:flutter/material.dart';
import 'package:flutter/widgets.dart';

import 'store.dart';

void main() {
  runApp(ExampleApp());
}

// ignore: use_key_in_widget_constructors
class ExampleApp extends StatelessWidget {
  final store = ExampleStore();

  @override
  Widget build(BuildContext context) => MaterialApp(
        home: Scaffold(
          body: Center(
            child: SingleChildScrollView(
              child: Column(
                mainAxisAlignment: MainAxisAlignment.center,
                children: [
                  SizedBox(
                    height: 700,
                    child: store.listenable(
                      (context, state, child) => Visibility(
                        visible: state.enabled,
                        child: ListView.separated(
                          itemBuilder: (context, idx) => store.listenable(
                            (context, state, _) => Text('${state.counter}'),
                          ),
                          separatorBuilder: (context, idx) => const Divider(),
                          itemCount: 20,
                        ),
                      ),
                      topics: {#enabled},
                    ),
                  ),
                ],
              ),
            ),
          ),
          bottomNavigationBar: Padding(
            padding: const EdgeInsets.all(16),
            child: Row(
              mainAxisAlignment: MainAxisAlignment.spaceBetween,
              children: [
                RaisedButton(
                  onPressed: () => store.multiply(2),
                  child: const Text('Increment'),
                ),
                RaisedButton(
                  onPressed: store.toggle,
                  child: const Text('Toggle'),
                ),
              ],
            ),
          ),
        ),
      );
}

Introduction

Goals

ToDo

  • x core functionality
  • x basic tests
  • more tests
  • error handling
  • logging
  • dev tools
  • improve documentation

State

A simple State can be declared as follows

import 'package:favour_state/favour_state.dart';

class ExampleState extends StoreState<ExampleState> {
  @override
  ExampleState copyWith() => ExampleState();
}

Any state used in the store must extend or implement StoreState<T> where T is the state type that extends or implements StoreState

Any state must implement the copyWith method. Since the state must be immutable, the copyWith method is the only way to partially change the state.


Store

A simple Store can be declared as follows

import 'package:favour_state/favour_state.dart';

import 'state.dart';

class ExampleStore extends BaseStore<ExampleState> {
  @override
  void initReactions() {}

  @override
  ExampleState initState() => ExampleState();
}

Any Store must extend BaseStore<T> where T is the state type that extend or implement StoreState and used with this Store.

Any Store must implement initReactions and initState methods. Method initState should return instance of state which conforms to T. Method initReactions could be empty.

Internals

Work in progress


Reactions

Work in progress

Value Reaction

Work in progress

Effect Reaction

Work in progress

Internals

Work in progress


Actions

Class-based action

Work in progress

Action from helper function

Work in progress

Internals

Work in progress


AppState

Work in progress

Services provider

Work in progress

Store registration

Work in progress

Get store by type

Work in progress

Internals

Work in progress


Widgets

Work in progress

AppStateProvider

Work in progress

AppStateScope

Work in progress

Internals

Work in progress


Internals

Work in progress

StoreRuntime

Work in progress

Libraries

favour_state