jasn

My take on bringing the Widget to the Stateful.

Features

• Basically uses StatefulWidgets as Controller to store your logic, moving the build(BuildContext) to the Widget part.

StateWidget: Widget to use instead of StatefulWidget. StateController: "stateful" class to use instead of State

ParentStateWidget<StateController> (or the mixin on StatelessWidget ParentStateMixin<StateController>) to inherit a "state" from a parent StateController.

• Provides a basic dependency injection with Bucket.

• Has a NotifierValue<T>, a glorified reactive ValueNotifier. That works with Observer() and ObserverBuilder() widgets.

• Makes heavy usage of extensions on BuildContext. To dispatch notifications, you can use context.notifyData() and capture it up in the tree with NotificationListener()

Getting started

Install with:

dependencies:
  jasn:
    git: https://github.com/roipeker/jasn.git

Usage

Buckets

Create Bucket: final bucket = Bucket(); or use the singleton Bucket.instance

Inject an instance:

bucket.put(MyService());

Lazy initialization (creates instance when its retrieved).

bucket.lazyPut(()=>MyService());

Factory instance generation (creates a new instance each time is retrieved)

bucket.factory(()=>MyService());

Retrieve an Instance:

final MyService service = bucket.get();

// or callable version 
bucket<MyService>();

Remove an instance:

bucket.delete<MyService>();

Reset all instances:

bucket.reset();

Check if it exists:

bucket.exists<MyService>()

---

StateController and Widget

class HomePage extends StateWidget<HomePageState> {
  const HomePage({Key? key}) : super(key: key);
  
  @override
  createState() => HomePageState();
 
  /// Like an StatefulWidget but `build()` comes here.  
  @override
  Widget build(BuildContext context) {
    return Scaffold(
       appBar: AppBar(),
       body: HomeMenu(),
    );
  }
}

/// The State is a `StateController`
class HomePageState extends StateController<HomePage> {
  late final name = 'Nick'.obs();
  late final switcher = false.obs(onChange: onSwitchChange);
  
  String get someUserName => bucket<SomeService>().username;

  @override
  void dispose() {
    name.dispose();
    switcher.dispose();
    super.dispose();
  }

  void onChangeNamePress() {
    name.value += 'o';
  }
}


/// A Stateless widget... that searches for a parent StateController
class HomeMenu extends ParentStateWidget<HomePageState> {
  const HomeMenu({Key? key}) : super(key: key);
  
  @override
  Widget build(BuildContext context) {
    
    /// you can "subscribe" to `NotifierValue` (.obs) as if it where InheritedWidgets.
    /// This Stateless will rebuild when `switcher` changes.
    final value = context.listen(state.switcher);
    return Column(
        children:[
        Observer(() => Text(state.name)),
        Observer(() => Text("switch is: $value")),
    ]);
   }
}

Additional information

Is just a playful idea to stay purist on Flutter.