An MVVM state management library which let full access to widget state.

🧐 What is it ?

Hermep provide a way to create an MVVM page structure and let you full access to the widget state. Coding & testing will be easier 😇

To summarize It's just a very simple wrapper to split your code logic 😎

👻 Getting started

• Create a model file <your_class>_viewmodel.dart

class YourClassModel with HermepModel {
  late int counter;
}

• Create the presenter file <your_class>_presenter.dart.

class YourClassPresenter with HermepPresenter<YourClassModel, YourClassView> {
  YourClassPresenter(
    YourClassView viewInterface,
  ) {
    this.viewModel = YourClassModel();
    this.viewInterface = viewInterface;
  }

  @override
  void dispose() { }

  @override
  void init() { }
}

• Create the page file <your_class>.dart.

mixin YourClassView {}

class YourClassPage extends StatefulWidget {
  YourClassPage({Key? key}) : super(key: key);

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

class _YourClassPageState extends HermepPage<YourClassModel, YourClassPresenter> with YourClassView {
  @override
  void createAnimations() { }

  @override
  void afterViewInit() { }

  @override
  HermepPresenter createPresenter() => YourClassPresenter(this);

  @override
  Widget build(BuildContext context) {
    return Text('Your Page');
  }
}

💫 Animations

Yes you can use animations with Hermep and it's very easy !

• In your model.dart file, create the animation & value notifier (used to trigger animation)

class YourClassModel with HermepModel {
  late ValueNotifier<bool> triggerAnimation;
  late Animation<double> animation;

  YourClassModel();
}

• In your presenter.dart file, init the animation value notifier.

// [...]
@override
void init() {
  this.viewModel.triggerAnimation = new ValueNotifier(false);
}
// [...]

• In your page, override the createAnimations() method to init the animation controller & assign animation tween.

// [...]
@override
void createAnimations() {
  this.animationControllers = {
    this.viewModel.triggerAnimation: AnimationController(
      duration: const Duration(seconds: 2),
      vsync: this,
    )
  };

  this.viewModel.animation = Tween<double>(
    begin: 50,
    end: 300,
  ).animate(this.animationControllers.values.first)
    ..addListener(() => this.refreshView());
}
// [..]

• To trigger on or off your animation, just set the value notifier in your presenter 🎉.

// launch the animation
this.viewModel.triggerAnimation.value = true;

// stop the animation
this.viewModel.triggerAnimation.value = false;

✅ Testing

Hermep can be fully tested by getting the presenter & model instances directly from your tests. This can be achieved with only 3 lines of code 😎.

final dynamic yourClassPageState = tester.state(find.byType(YourClassPage));
final YourClassPresenter presenter = yourClassPageState.presenter;
final YourClassModel model = yourClassPageState.viewModel;

You can now check all your model data & trigger some functions from your presenter in your test 🚀.

Psst 🤫 !

You can use Hermep with Koby for VSCode to generate all needed files (presenter, model & page) with 2 clicks 🤩.

👥 Contributions

Contributions are welcome. Contribute by creating a PR or create an issue 🎉.