contra 0.0.2

Small Internal Package to manage MVC Architecture in our app

Contra

[coverage]

Contra is a minimal internal package designed to manage the MVC (Model-View-Controller) architecture within our app. It is currently under development, and improvements will be made accordingly.

The primary goal of Contra is to integrate Riverpod with our controller, providing a proper way to manage our project effectively.

Features

• ContraView: A widget to hold most views that can be propagated with our controller.
• ContraController: A controller to hold most of our view logic.
• ContraWidget: A widget that allows subwidgets of the ContraViewBuilder to access the controller easily.
• Internal Busy State Management: Each controller has an internal busy state that tracks the loading state of views, making it easy to set the loading state of a view.

Usage

ContraView Example

class RandomTextView extends StatelessWidget {
  const RandomTextView({super.key});

  @override
  Widget build(BuildContext context) {
    return ContraViewBuilder(
      builder : (BuildContext context, RandomTextController controller){
        return Scaffold(
          appBar: AppBar(
            title: const Text('Contra Example'),
          ),
          body: Column(
            mainAxisAlignment: MainAxisAlignment.center,
            children : [
              Text(controller.text),
              const SizedBox(height: 20),
              ElevatedButton(
                onPressed:(){
                  controller.generateText();
                },
                child: const Text('Generate'),
              ),
            ],
          ),
        );
      },
      controllerBuilder: () => RandomTextController(),
    );
  }
}

ContraController Example

class RandomTextController extends ContraController{
  RandomTextController(): super();

  String get text => ref.watch(_textProvider);

  String _generateRandomDynamicText() {
    final random = Random();
    const characters = 'abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ0123456789';

    return String.fromCharCodes(
      List.generate(8, (_) => characters.codeUnitAt(random.nextInt(characters.length))),
    );
  }

  void generateText(){
    var randomText = _generateRandomDynamicText();
    ref.read(_textProvider.notifier).state = randomText;
  }
}

final _textProvider = StateProvider((ref) => 'hello');

ContraWidget Example

class RandomTextSubWidget extends ContraWidget<RandomTextController>{
  @override
  Widget build(BuildContext context, RandomTextController controller){
    return Text(
      'This is a styled random text ${controller.text}',
      style: Theme.of(context).textTheme.bodyLarge!.copyWith(
        color: Colors.amber,
        fontWeight: FontWeight.bold,
        fontStyle: FontStyle.italic,
      ),
    );
  }
}

Internal Busy State Management Example

class RandomTextView extends StatelessWidget {
  const RandomTextView({super.key});

  @override
  Widget build(BuildContext context) {
    return ContraViewBuilder(
      builder : (BuildContext context, RandomTextController controller){
        return Scaffold(
          appBar: AppBar(
            title: const Text('Contra Example'),
          ),
          body: Column(
            mainAxisAlignment: MainAxisAlignment.center,
            children : [
              AnimatedCrossFade(
                firstChild: Text(controller.text),
                secondChild: const CircularProgressIndicator(),
                duration: const Duration(milliseconds: 2000),
                crossFadeState: controller.isBusy ? CrossFadeState.showSecond :  CrossFadeState.showFirst,
              ),
              const SizedBox(height: 20),
              ElevatedButton(
                onPressed:(){
                  controller.generateText();
                },
                child: const Text('Generate'),
              ),
            ],
          ),
        );
      },
      controllerBuilder: () => RandomTextController(),
    );
  }
}

class RandomTextController extends ContraController{
  RandomTextController(): super();

  String get text => ref.watch(_textProvider);

  String _generateRandomDynamicText() {
    final random = Random();
    const characters = 'abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ0123456789';

    final generatedText =  String.fromCharCodes(
      List.generate(8, (_) => characters.codeUnitAt(random.nextInt(characters.length))),
    );

    return Future.value(generatedText);
  }

  void generateText() async {
    setBusy(true);
    var randomText = await _generateRandomDynamicText();
    ref.read(_textProvider.notifier).state = randomText;
    setBusy(false);
  }

}

final _textProvider = StateProvider((ref) => 'hello');

You could also set the busy state for different objects too

class RandomTextController extends ContraController{
  RandomTextController(): super();



  String get text => ref.watch(_textProvider);

  String _generateRandomDynamicText() {
    final random = Random();
    const characters = 'abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ0123456789';

    final generatedText =  String.fromCharCodes(
      List.generate(8, (_) => characters.codeUnitAt(random.nextInt(characters.length))),
    );

    return Future.value(generatedText);
  }

  void generateText() async {
    setBusyForObject('generating', true);
    var randomText = await _generateRandomDynamicText();
    ref.read(_textProvider.notifier).state = randomText;
    setBusyForObject('generating', false);
  }

}

final _textProvider = StateProvider((ref) => 'hello');

You could also set the busy state of the controller simultaneously while running an asynchronous function

class RandomTextController extends ContraController{
  RandomTextController(): super();



  String get text => ref.watch(_textProvider);

  String _generateRandomDynamicText() {
    final random = Random();
    const characters = 'abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ0123456789';

    final generatedText =  String.fromCharCodes(
      List.generate(8, (_) => characters.codeUnitAt(random.nextInt(characters.length))),
    );

    return Future.value(generatedText);
  }

  void generateText() async {
    try{
      var randomText = await runBusyFuture(
        _generateRandomDynamicText(),
        throwException: true,
      );
      ref.read(_textProvider.notifier).state = randomText;
    } catch(e){
      // handle your error
    }

  }

}

final _textProvider = StateProvider((ref) => 'hello');