Consuming controller state in Flutter

Import the optional widgets entry point:

import 'package:jintent/widgets.dart';

These widgets work directly with JController; a provider package is optional. They do not create or dispose controllers. The caller owns the controller and must keep it alive while the widget uses it.

Build from a state

Given a CounterController with a CounterState.count field:

JControllerBuilder<CounterState>(
  controller: controller,
  builder: (context, state) => Text('${state.count}'),
)

The initial state is available on the first build. Later state notifications schedule a rebuild; multiple changes before a Flutter frame can be coalesced. This is a view of current state, not a recorder of every transition. Use JStateRecorder from the testing entry point to record transitions.

Select a value

JControllerSelector<CounterState, int>(
  controller: controller,
  selector: (state) => state.count,
  builder: (context, count) => Text('$count'),
)

For controller notifications, the selector rebuilds only when the selected value differs by ==. Updating an unrelated field does not rebuild that builder. Parent or inherited-widget rebuilds still work normally. Select immutable values with meaningful equality; mutating a selected list in place is not supported.

Replacing the controller detaches the old listener and uses the new state immediately. Replacing the selector recomputes the selection, even without a state notification. Removing the widget detaches its listener without disposing the controller.

Keep effects outside builders

Use JEffectListener for dialogs, navigation and feedback. Builders and selectors may run repeatedly and must not perform one-time side effects.

An awaited effect timing out does not automatically dismiss its UI. The consumer owns that UI policy. The example dialog helper binds one dialog route to its effect’s result: it removes only that route when the effect settles externally and leaves newer routes untouched. See effects for the underlying timeout and disposal contracts.