state library

Reactive state, and the widgets that observe it.

The observable primitives a state class is built from — Rx, RxList and RxEvent — together with the widgets that read them: Obx for values, EventListener for one-off signals.

class CounterState {
  final count = Rx<int>(0);
}

Obx((ref) => Text('${ref.watch(state.count)}'))

These are plain Listenable/ValueListenable implementations, so ValueNotifier, ChangeNotifier, TextEditingController and friends work with ref.watch, and with a controller's sync/subscribe, just as well.

Controllers and the widget that binds one to a subtree live in package:subtree/subtree.dart.

Classes

EventListener<T>

Runs listener with a BuildContext every time event fires, and renders child unchanged.

Obx

Rebuilds its builder whenever an observable read through ref.watch changes.

ObxWidget

Base class for widgets that build inside a reactive block.

ReactiveBlock

A reactive block outside the widget tree.

ReactiveBlockRef

Read access to observables that also subscribes the caller to them.

ReactiveBlockRefExt

The ref handed to an Obx builder: ReactiveBlockRef plus widget-only helpers.

Rx<T>

A single observable value — the basic building block of a state class.

RxEvent<T>

A fire-and-forget signal: navigation, toasts, "the link was invalid".

RxList<T>

An observable list whose value is always unmodifiable.

StateObx<S extends Object>

An Obx that also resolves S from the enclosing subtree.