blackbox_jaspr

Jaspr bindings for blackbox — state management with one law: output = compute(input, state).

Your boxes are pure Dart and identical between Flutter and Jaspr — this package provides the web-side delivery and persistence:

• BoxObserver — rebuilds a component when the boxes it actually read change;
• BoxProvider + context.box<T>() — delivery down the component tree;
• LocalStorageStore — persistence backend for state(persist:) cells and Cache(persist:) on top of window.localStorage.

Setup

void main() {
  LocalStorageStore.preload();           // persistence backend, once

  final app = createApp(...);            // your graph — pure Dart,
                                         // often the same createApp as the Flutter app
  runApp(BoxProvider.multi(
    boxes: app.boxes,
    child: const App(),
  ));
}

Reading boxes

class CounterView extends StatelessComponent {
  @override
  Iterable<Component> build(BuildContext context) sync* {
    final counter = context.box<CounterBox>();
    yield BoxObserver(builder: (_) sync* {
      yield text('${counter.value}');
      yield button(onClick: counter.increment, [text('+')]);
    });
  }
}

BoxObserver subscribes to exactly what the builder reads — components rebuild independently, at the rhythm of their own data.

Testing — swap boxes by type

BoxProvider.overrides(
  overrides: [BoxOverride.of<CounterBox>(mockCounter)],
  child: componentUnderTest,
);

BoxProvider.multi asserts on two boxes of the same runtime type — collisions are loud, never silent.

See the blackbox README for the model, and ARCHITECTURE.md for how a whole production app is assembled.