vm 1.0.4

A very simple flutter plugin that implements the `MVVM` pattern.

Flutter VM (ViewModel)

A very simple flutter plugin that implements the MVVM pattern.

Model–View–ViewModel (MVVM) is a software architectural pattern that facilitates the separation of the development of the graphical user interface (the view) – be it via a markup language or GUI code – from the development of the business logic or back-end logic (the model) so that the view is not dependent on any specific model platform.

Getting Started

• Add this to your pubspec.yaml

  dependencies:
  vm: ^1.0.3
  

• Get the package from Pub:

  flutter packages get
  

• Import it in your file

  import 'package:vm/vm.dart';
  

Features

...

Usage

First create a ViewModel

class CounterViewModel extends ViewModel {
  int value = 0;
  int progress = 0;

  void increment() {
    value++;
    if (value % 5 == 0) {
      progress += 1;
    }
    notifyListeners();
  }
}

Using CounterViewModel with ViewModelBuilder

ViewModelBuilder<CounterViewModel>(
  model: CounterViewModel(),
  builder: (context, model, child) {
    return Text('Counter: ${model.value}');
  },
)

Rebuild only if progress changed

ViewModelBuilder<CounterViewModel>(
  model: counterModel,
  shouldRebuild: (prev, next) => prev.progress != next.progress
  builder: (context, model, child) => Text('Progress: ${model.progress}'),
)

Or using context.select

ViewModelBuilder<CounterViewModel>(
  model: counterModel,
  builder: (context, model, child) => const _Progress(),
)

class _Progress extends StatelessWidget {
  const _Progress({Key? key}) : super(key: key);

  @override
  Widget build(BuildContext context) {
    final progress = context.select((CounterViewModel m) => m.progress);
    return Text('Progress: $progress');
  }
}

Rebuild only if progress is an odd number

ViewModelBuilder<CounterViewModel>(
  model: counterModel,
  shouldRebuild: (prev, next) => next.progress & 1 == 1,
  builder: (context, model, child) => Text('Progress: ${model.progress}'),
)

Check out the complete Example

Changelog

Please have a look in CHANGELOG

Maintainers

• Vlad Korniienko
• Alex Awaik

License