alien_signals 0.0.3

The lightest signal library - Dart implementation of alien-signals.

Alien Signals for Dart

The lightest signal library for Dart, ported from stackblitz/alien-signals.

Installation

Add to your pubspec.yaml:

dependencies:
  alien_signals: latest

Basic Usage

import 'package:alien_signals/alien_signals.dart';

void main() {
  // Create a signal
  final count = signal(0);

  // Create a computed value
  final doubled = computed((_) => count.get() * 2);

  // Create an effect
  effect(() {
    print('Count: ${count.get()}, Doubled: ${doubled.get()}');
  });

  // Update the signal
  count.value = 1; // Prints: Count: 1, Doubled: 2
}

Core Concepts

Signals

Signals are reactive values that notify subscribers when they change:

final name = signal('Alice');

print(name.get()); // Get value using call `get` fn.
name.set('Bob');   //Set value using call `set` fn.

// or
print(name()); // Get value using call syntax
name('Bob');   // Set value using call syntax

// or
print(name.value); // Get using property syntax
name.value = 'Bob'; // Set using property syntax

Computed Values

Computed values automatically derive from other reactive values:

final firstName = signal('John');
final lastName = signal('Doe');
final fullName = computed((_) => '${firstName.get()} ${lastName.get()}');

effect(() => print(fullName())); // Prints: John Doe
lastName.value = 'Smith';        // Prints: John Smith

Effects

Effects run automatically when their dependencies change:

final user = signal('guest');

final e = effect(() {
  print('Current user: ${user()}');
});

// Cleanup when done
e.stop();

Effect Scopes

Group and manage related effects:

final scope = effectScope();
scope.run(() {
  // Effects created here are grouped
  effect(() => print('Effect 1'));
  effect(() => print('Effect 2'));
});

// Clean up all effects in scope
scope.stop();

Compat

Allows you to manipulate signals using the .value property:

import 'package:alien_signals/alien_signals.dart';
import 'package:alien_signals/compat.dart';

void main() {
  final count = signal(0);
  effect(() => print(count.value); // print 0

  count.value++; // print 1
}

API Reference

See the API documentation for detailed information about all available APIs.

License

This project is licensed under the MIT License - see the LICENSE file for details.

Credits

This is a Dart port of the excellent stackblitz/alien-signals library.