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rodydavis/signals.dart ★9999⑂99

Type: MapSignal

API reference and details for MapSignal from signals.dart.

MapSignal#

Kind: class & function  |  Package: package:signals_core

Class: MapSignal#

A reactive Signal that holds a Map and implements the Map interface.

MapSignal lets you listen to changes on a map reactively and mutate it directly using standard map operations (like adding/modifying keys with operator []=, addAll, remove, clear, etc.). Any mutations automatically trigger reactive updates to all active listeners (e.g., inside an effect or computed).

Additionally, MapSignal defines convenient operators:

  • << injects/adds all entries from another map into the current map.
  • & forks/concatenates the map with another map into a new MapSignal.
  • | pipes/concatenates the map with another signal holding a map into a new MapSignal.

Example Usage#

import 'package:signals/signals.dart';

void main() {
  final settings = mapSignal<String, dynamic>({
    'theme': 'light',
    'notifications': true,
  });

  effect(() {
    print('Theme is currently: ${settings['theme']}');
  }); // Prints: "Theme is currently: light"

  // Update key/value pair directly (triggers updates)
  settings['theme'] = 'dark'; // Prints: "Theme is currently: dark"

  // Expose standard Map methods
  settings.remove('notifications');
}
Mutating the collection directly calls the reactive set() routine under the hood automatically. You do not need to assign settings.value = ... manually!

Members of MapSignal#

Member Type Signature Description
MapSignal constructor dart MapSignal(super.value, {MapSignalOptions<K, V>? options, @Deprecated('Use options: MapSignalOptions(autoDispose: ...) instead') bool? autoDispose, @Deprecated('Use options: MapSignalOptions(name: ...) instead') String? debugLabel}) Creates a MapSignal with the given value.
<< method dart MapSignal<K, V> <<(Map<K, V> other) Inject: Update current signal value with iterable
& method dart MapSignal<K, V> &(Map<K, V> other) Fork: create a new signal with value is the concatenation of source signal and iterable parameter
** ** method dart MapSignal<K, V>
== method dart bool ==(Object other)
hashCode method dart int hashCode

Function: mapSignal#

MapSignal<K, V> mapSignal(Map<K, V> map, {MapSignalOptions<K, V>? options, @Deprecated('Use options: MapSignalOptions(autoDispose: ...) instead') bool? autoDispose, @Deprecated('Use options: MapSignalOptions(name: ...) instead') String? debugLabel})

Creates a MapSignal initialized with the provided map.

This is a convenience helper function for creating reactive map signals.

import 'package:signals/signals.dart';

final settings = mapSignal({'theme': 'dark'});

References#

The MapSignal type is referenced and used in the following pages: