useMapSignal#
Kind:
function |
Package: package:signals_hooks
Function: useMapSignal#
MapSignal<K, V> useMapSignal(Map<K, V> value, {List<Object?> keys = const <Object>[], MapSignalOptions<K, V>? options})
Creates a new MapSignal and subscribes to it.
A MapSignal provides a reactive wrapper around a standard Dart Map. It tracks in-place mutations (such as entry addition, value updates, or key removals) and automatically triggers rebuilds of the host HookWidget.
Excellent for storing state dictionaries, form configurations, cached records, or key-value structures
that require fine-grained reactivity.
Parameters#
- value: The initial map entries.
- options: The options for the signal.
- keys: A list of objects to watch. If any key changes, the map signal is re-created.
Example#
import 'package:flutter/material.dart';
import 'package:flutter_hooks/flutter_hooks.dart';
import 'package:signals_hooks/signals_hooks.dart';
class DynamicFormWidget extends HookWidget {
const DynamicFormWidget({super.key});
@override
Widget build(BuildContext context) {
final formData = useMapSignal<String, String>({});
return Column(
children: [
TextField(
decoration: const InputDecoration(labelText: 'Email'),
onChanged: (val) => formData['email'] = val,
),
TextField(
decoration: const InputDecoration(labelText: 'Password'),
onChanged: (val) => formData['password'] = val,
),
Text('Live Form Data: ${formData.value}'),
],
);
}
}
References#
The useMapSignal type is referenced and used in the following pages:
- signals_hooks
- useMapSignal (signals_hooks/hooks)