useFutureSignal

Creates a new FutureSignal and subscribes to it.

A FutureSignal wraps a standard Dart Future in a reactive state container, allowing you to easily read the asynchronous operation's progress (loading, error, data) directly in your build method without needing FutureBuilder.

Parameters#

• value: A callback returning the Future to execute.
• keys: A list of objects to watch for changes. If any key in this list changes, the existing future is cancelled/ignored and a new future is created and subscribed to.
• initialValue: An optional initial value to display before the future completes.
• dependencies: An optional list of signals that this future depends on. If any dependency changes, the future is automatically re-run.
• lazy: If true (default), the future won't start executing until the signal's value is first read.
• debugLabel: An optional debug label to identify this signal in devtools.

Example#

import 'package:flutter/material.dart';
import 'package:flutter_hooks/flutter_hooks.dart';
import 'package:signals_hooks/signals_hooks.dart';

class UserProfileWidget extends HookWidget {
  final int userId;
  const UserProfileWidget({required this.userId, super.key});

  @override
  Widget build(BuildContext context) {
    // Re-fetches user profile if userId changes
    final userSignal = useFutureSignal(
      () => fetchUserProfile(userId),
      keys: [userId],
    );

    return userSignal.value.map(
      data: (user) => ListTile(
        title: Text(user.name),
        subtitle: Text(user.email),
      ),
      error: (err, stack) => Text('Error: $err'),
      loading: () => const CircularProgressIndicator(),
    );
  }
}