Watch can not react to lazy signal being initialiazed

[Solido]

Initializing a lazy signal will not trigger a Widget rebuild as .value maybe out of the logic execution (if condition) as isInitialized bar it.

We need the way to register signal() under Watch(...) without triggering a non initialized error.

Thanks!

Quick code for you to reproduce

import 'dart:math';

import 'package:flutter/material.dart';
import 'package:signals_flutter/signals_flutter.dart';

void main() {
  runApp(const MyApp());
}

class MyApp extends StatelessWidget {
  const MyApp({super.key});

  // This widget is the root of your application.
  @override
  Widget build(BuildContext context) {
    return const MaterialApp(
      home: MyHomePage(title: 'Flutter Demo Home Page'),
    );
  }
}

class MyHomePage extends StatefulWidget {
  const MyHomePage({super.key, required this.title});

  final String title;

  @override
  State<MyHomePage> createState() => _MyHomePageState();
}

class _MyHomePageState extends State<MyHomePage> {
  final signal = lazySignal<int>();

  @override
  build(_) => Scaffold(
        body: Center(
          child: Column(
            mainAxisAlignment: MainAxisAlignment.center,
            children: <Widget>[
              const Text(
                'You have pushed the button this many times:',
              ),
              Watch((_) => Text(
                    signal.isInitialized ? '${signal()}' : '?',
                    style: Theme.of(context).textTheme.headlineMedium,
                  )),
            ],
          ),
        ),
        floatingActionButton: FloatingActionButton(
          onPressed: () {
            signal.value = Random().nextInt(200);
            print(signal.peek());
          },
          tooltip: 'Increment',
          child: const Icon(Icons.add),
        ),
      );
}

[rodydavis]

This is interesting! I will see if I can find a way to trigger a subscription.

But it also may be a works as expected too. Will do some research!

[Solido]

We may have something like isInitialized(), a method not a getter, that trigger a soft registration under Watch

I'm too busy using signals.dart but I'm curious how react, angulars and other deal with such case :)

[Solido]

Another approach would be a Lazy widget that act like Visibility
Child act like a wrapped Watch

Lazy( mySignal, 
  unset: Text('not cooked'),
  child: Text(mySignal());

[Solido]

Keep the wonderful simple api with

Watch((_) => ...), lazies = [lazySignal1, lazySignal2])

Should be easier to implement to.

[rodydavis]

I think another approach would be to make the initialization check a signal too so it will subscribe regardless!

[Solido]

If possible it would be the best option! Le mar. 3 sept. 2024 à 21:41, Rody Davis ***@***.***> a écrit :

…

I think another approach would be to make the initialization check a signal too so it will subscribe regardless! — Reply to this email directly, view it on GitHub <#310 (comment)>, or unsubscribe <https://github.com/notifications/unsubscribe-auth/AAJ4MWIMQXRIA32DOMVNURDZUYGHFAVCNFSM6AAAAABNSSS3HWVHI2DSMVQWIX3LMV43OSLTON2WKQ3PNVWWK3TUHMZDGMRXGI4TCNJWHE> . You are receiving this because you authored the thread.Message ID: ***@***.***>