get_notifier plugin

GetNotifier aims to combine the power of ChangNotifier and GetIt DI plugin to work together. It is the way to avoid context tracking over a different part of the app.

Features:

• Use Get_It plugin get_it to inject singleton or factory dependencies anywhere in the code;
• Easely perform ChangeNotifier UI mutation using Consumer widget;

Getting Started

• Add get_it and get_notifier to the pubspec.yaml file.

dependencies:
  ...
  get_notifier:

Then run

flutter pub get

• Create state file extending ChangeNotifier app_model.dart

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

class AppModel extends ChangeNotifier {
  AppModel() {
  int _counter = 0;
  int get counter => _counter;
  set counter(int val) {
    _counter = val;
    notifyListeners();
  }
}

• Register it into the application together with other DI parts main.dart

import 'package:flutter/material.dart';
import 'package:get_notifier/get_notifier.dart';
import 'package:get_notifier_example/app_model.dart';
import 'package:get_notifier_example/service.dart';

// This is our global ServiceLocator
GetIt getIt = GetIt.instance;
void main() {
  getIt
    ..registerSingleton(AppModel(), signalsReady: true)
    ..registerFactory(() => Service());

  runApp(const MyApp());
}

• You now can separate state from mutation actions for the sake of code readability service.dart

import 'package:get_notifier_example/app_model.dart';

class Service {
  final appModel = GetIt.I.get<AppModel>();

  void incrementCounter() {
    appModel.counter += 1;
  }
}

Usage in UI

To utilise simple DI fuctionality inject singleton or factory just as GetIt plugin recomends:

final appModel = GetIt.I.get<AppModel>();

To make statless part of the UI, which does not rebuild due to the notifyListrers() method of ChangeNotifier ancestor simply use one of six Workers to collect up to 6 different ChangeNotifier classes in one snipet:

1. Worker<A>(builder: (a, child)=> ...)
2. Worker2<A, B>(builder: (a,b, child)=> ...)
3. Worker3<A, B, C>(builder: (a,b,c, child)=> ...)
4. Worker4<A, B, C, D>(builder: (a,b,c,d, child)=> ...)
5. Worker5<A, B, C, D, E>(builder: (a,b,c,d,e, child)=> ...)
6. Worker6<A, B, C, D, E, F>(builder: (a,b,c,d,e,f, child)=> ...)

where A, B, C, D, E, and F are ChangeNotifier state classes

To make reactive part of the UI, which rebuilds due to the notifyListrers() method of ChangeNotifier ancestor simply use one of six Consumers:

1. Consumer<A>(builder: (a, child)=> ...)
2. Consumer2<A, B>(builder: (a,b, child)=> ...)
3. Consumer3<A, B, C>(builder: (a,b,c, child)=> ...)
4. Consumer4<A, B, C, D>(builder: (a,b,c,d, child)=> ...)
5. Consumer5<A, B, C, D, E>(builder: (a,b,c,d,e, child)=> ...)
6. Consumer6<A, B, C, D, E, F>(builder: (a,b,c,d,e,f, child)=> ...)

where A, B, C, D, E, and F are ChangeNotifier state classes

For example:

import 'package:flutter/material.dart';
import 'package:get_it/get_it.dart';
import 'package:get_notifier/get_notifier.dart';
import 'package:get_notifier_example/app_model.dart';
import 'package:get_notifier_example/service.dart';

class MyHomePage extends StatelessWidget {
  MyHomePage({Key? key, required this.title}) : super(key: key);
  @override
  Widget build(BuildContext context) {
    return Material(Scaffold(
                appBar: AppBar(
                  title: Text('Title'),
                ),
                body: Center(
                    child: Column(
                      mainAxisAlignment: MainAxisAlignment.center,
                      children: <Widget>[
                        const Text(
                          'You have pushed the button this many times:',
                        ),
                        Consumer<AppModel>(builder: (appModel, child) {
                          return Text(
                          appModel.counter.toString(),
                          style: Theme.of(context).textTheme.headline4,
                          ),
                        }),
                      ],
                    ),
                  );
                floatingActionButton: Worker<Service>(builder: (s, child) {
                  return FloatingActionButton(
                    onPressed: () {
                      s.incrementCounter();
                    },
                    tooltip: 'Increment',
                    child: const Icon(Icons.add),
                  );
                }),
              );
            
          }),
    );
}

That's it!

More about

This project is a starting point for a Flutter plug-in package, a specialized package that includes platform-specific implementation code for Android and/or iOS.

For help getting started with Flutter, view our online documentation, which offers tutorials, samples, guidance on mobile development, and a full API reference.

Happy coding.