noir_signals

Reusable widget lifecycle hooks and Signals reactive state for Noir, the Flutter-like terminal UI framework for Dart.

This package is optional. Installing Noir alone does not pull it in.

Start with the task-list tutorial, which begins at Build a task list. Its five lessons connect hook-owned text input, signals, computed remaining and visible lists, and user actions in one runnable app.

Install

Add the companion beside Noir. It requires Noir 0.0.2:

dart pub add noir noir_signals

dependencies:
  noir: ^0.0.2
  noir_signals: ^0.0.1-alpha.0

Inside the Noir repository

The repository is one Pub workspace, so dart pub get at its root resolves both packages. The task-list tutorial builds its app there, in packages/noir_signals/example/.

From a repository checkout

To evaluate unreleased changes, clone Noir beside your application directory, pin an exact commit or tag, and resolve both packages from that revision:

dependencies:
  noir: ^0.0.2
  noir_signals:
    path: ../noir/packages/noir_signals
dependency_overrides:
  noir:
    path: ../noir/packages/noir

The override routes the companion's own noir dependency to the same checkout, so one revision supplies both packages.

Import

One entrypoint carries the whole surface:

import 'package:noir/noir.dart';
import 'package:noir_signals/noir_signals.dart';

Use SignalWidget

Extend SignalWidget to retain lifecycle hooks and reactive state across builds. Use SignalBuilder when a small inline subtree needs hooks.

class Counter extends SignalWidget {
  const Counter({super.key});

  @override
  Widget build(BuildContext context) {
    final count = useSignal(0);
    return Button(label: '${count.value}', onPressed: () => count.value++);
  }
}

useSignal owns and observes the value above. Use useState for a simple local value, or useComputed for a value derived from other signals. Hooks must be called in the same order on every build.

There is no automatic whole-build tracking. Observe borrowed signals with useSignalValue or SignalValueBuilder; a plain .value read does not subscribe the widget. The package also re-exports the public signals_core primitives needed to define a model.

Examples and reference

The example directory contains the runnable counter, task list, and file search, with setup and run commands. The tutorial's earlier checkpoints are in example/tutorials/task_list/; its final checkpoint is example/task_list.dart.

• Hooks reference: hook families, call order, resource ownership, and custom hooks.
• Signals reference: signal ownership, observation, replacement, and effect cleanup.

Boundaries

The production code here imports only package:noir/noir.dart and the public signals_core API. It reaches no Noir private library, no low-level or FFI barrel, and no native code. Noir keeps owning scheduling, reconciliation, layout, paint recording, and native resources.

License

BSD 3-Clause. See LICENSE.