type 'Null' is not a subtype of type 'WidgetsLocalizations' in type cast for Arabic, Najdi

[Kal-Elx]

Version

3.1.0

Library

feedback

Flutter channel

stable

Flutter version

3.29.3

Platform

iOS

Details

We noticed the following issue surfacing in Crashlytics where some users were unable to open the app.

_LocalizationsState._textDirection
FlutterError - type 'Null' is not a subtype of type 'WidgetsLocalizations' in type cast. Error thrown .

Thanks to this comment we narrowed down the issue to this package and specifically to devices with the language Arabic, Najdi. Other Right-to-left languages I've tested works as expected.

Steps to reproduce

• Change your device language to Arabic, Najdi
• Run the example project

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

void main() {
  runApp(BetterFeedback(child: const MyApp()));
}

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

  @override
  Widget build(BuildContext context) {
    return MaterialApp(
      home: Scaffold(body: Center(child: Text('Hello, World!'))),
    );
  }
}

• You will see the following error
  

Output of flutter doctor -v

Doctor summary (to see all details, run flutter doctor -v):
[✓] Flutter (Channel stable, 3.29.3, on macOS 15.4.1 24E263 darwin-arm64, locale en-US)
[✓] Android toolchain - develop for Android devices (Android SDK version 35.0.0)
[✓] Xcode - develop for iOS and macOS (Xcode 16.3)
[✓] Chrome - develop for the web
[✓] Android Studio (version 2024.3)
[✓] VS Code (version 1.99.3)
[✓] Connected device (5 available)
[✓] Network resources

• No issues found!

[Kal-Elx]

The issue also occurs for Neapolitan (nap_IT).

[empathictech]

Haitian Creole (ht) as well

[empathictech]

Was able to resolve it for Haitian Creole. Turns out this is a core Flutter issue, not a Feedback issue.

Flutter has built in semantics for a handful of languages, but not all. For the more niche languages, we need to override the base Material, Cupertino, and Widgets Localizations...

https://api.flutter.dev/flutter/material/DefaultMaterialLocalizations-class.html
https://api.flutter.dev/flutter/cupertino/DefaultCupertinoLocalizations-class.html
https://api.flutter.dev/flutter/widgets/DefaultWidgetsLocalizations-class.html

Then include them in main...

-- Sample BetterFeedback entry --

localizationsDelegates: <LocalizationsDelegate>[
EzFeedbackLD(),
CreoleMaterialLocalizations.delegate,
CreoleCupertinoLocalizations.delegate,
const CreoleWidgetsLocalizationsDelegate(),
],

-- Sample PlatformApp entry --

localizationsDelegates: <LocalizationsDelegate>{
const LocaleNamesLocalizationsDelegate(),
...EFUILang.localizationsDelegates,
...Lang.localizationsDelegates,
CreoleMaterialLocalizations.delegate,
CreoleCupertinoLocalizations.delegate,
const CreoleWidgetsLocalizationsDelegate(),
},

Here's my implementation for Creole. Pasting a dev link for now, just switch to main if/when the link dies:
https://github.com/Empathetech-LLC/empathetech_flutter_ui/blob/dev/lib/src/consts/custom_delegates/creole.dart