How to use this package with existing l10n.dart files

[jeromeDms]

Hi All
I'm developing 2 apps with shared code.
I created a package common_code, plus 2 apps using this common_code package.
My 2 apps have their own localization strings, and common_code package has also its own localization strings.
I'm facing the know issue with only the first localizationsDelegates working.

That's why I found your package.
I'm trying to use your package in my apps, but it seems I have to manually add all translated strings to the delegates ?

For instance, from your example: String get title => Intl.message('Multiple localization', name: 'title');

I already have l10n.dart files generated for both my apps as well as common_code.

The difference I see in l10n.dart and your code is the MultipleLocalizations.load rather than AppLocalizations.load in the load(Locale locale) function.

I was wondering if there is a way to use the existing l10n.dart that are automatically generated (and thus containing all strings localizations), and override the load function, rather than having to add manually all translations in the code ?

Hope I'm clear :-)
Thanks for any tips you could provide.

[greymag]

Hey! Unfortunately the plugin doesn't work with generated l10n.dart. I didn't find a way to inject my own load function. So you're right, you should make delegates in old fashion way - by hand, if you want to use localization from a package.

I haven't watched the latest version of Flutter though. But frenkly a hope that something will change is very small.

One of my idea to deal wit it was to add code generation task to change load function, but I didn't try it. In most of my projects I don't use auto generated localization - for my taste it's very inconvenient any way.

[jeromeDms]

Thanks for your prompt answer.
Yes code generation to modify the load function would be so cool, no need to manually add/remove translations.

[niskovmaksym]

I added this code inside main.dart

class _S extends S {
  static const _SDelegate delegate = _SDelegate();
}

class _SDelegate extends LocalizationsDelegate<S> {
  const _SDelegate();

  List<Locale> get supportedLocales {
    return const <Locale>[
      Locale.fromSubtags(languageCode: 'en'),
      Locale.fromSubtags(languageCode: 'de'),
      Locale.fromSubtags(languageCode: 'es'),
      Locale.fromSubtags(languageCode: 'pt'),
    ];
  }

  @override
  bool isSupported(Locale locale) => _isSupported(locale);

  @override
  Future<S> load(Locale locale) {
    return MultipleLocalizations.load(
        initializeMessages, locale, (l) => S.load(Locale(l)),
        setDefaultLocale: true);
  }

  @override
  bool shouldReload(LocalizationsDelegate<S> old) {
    return false;
  }

  bool _isSupported(Locale locale) {
    for (var supportedLocale in supportedLocales) {
      if (supportedLocale.languageCode == locale.languageCode) {
        return true;
      }
    }
    return false;
  }
}

This part was copied from generated file l10n.dart

List<Locale> get supportedLocales {
    return const <Locale>[
      Locale.fromSubtags(languageCode: 'en'),
      Locale.fromSubtags(languageCode: 'de'),
      Locale.fromSubtags(languageCode: 'es'),
      Locale.fromSubtags(languageCode: 'pt'),
    ];
  }

  @override
  bool isSupported(Locale locale) => _isSupported(locale);


  @override
  bool shouldReload(LocalizationsDelegate<S> old) {
    return false;
  }

  bool _isSupported(Locale locale) {
    for (var supportedLocale in supportedLocales) {
      if (supportedLocale.languageCode == locale.languageCode) {
        return true;
      }
    }
    return false;
  }

and I changed load method

@override
 Future<S> load(Locale locale) {
   return MultipleLocalizations.load(
       initializeMessages, locale, (l) => S.load(Locale(l)),
       setDefaultLocale: true);
 }

and inside MaterialApp I added this code

localizationsDelegates: const [
        _S.delegate,
        SModule1.delegate,
        SModule2.delegate,
        GlobalMaterialLocalizations.delegate,
        GlobalWidgetsLocalizations.delegate,
        GlobalCupertinoLocalizations.delegate,
      ],

main pubspec.yaml

flutter_intl:
  enabled: true
  class_name: S
  main_locale: en
  arb_dir: lib/l10n
  output_dir: lib/generated
  use_deferred_loading: false

module1 pubspec.yaml

flutter_intl:
  enabled: true
  class_name: SModule1
  main_locale: en
  arb_dir: lib/l10n
  output_dir: lib/generated
  use_deferred_loading: false

Intl Authogeneration working for me.

[niskovmaksym]

We need to add the overridden delegate only in the first position.
Translations are generated automatically and everything works well

localizationsDelegates: const [
        _S.delegate,
        SModule1.delegate,
        SZodiac.delegate,
        GlobalMaterialLocalizations.delegate,
        GlobalWidgetsLocalizations.delegate,
        GlobalCupertinoLocalizations.delegate,
      ],

[Maqcel]

@niskovmaksym Hi I'm currently investigating how to handle this issue can you somehow provide an example repo for it?

[niskovmaksym]

Hi) do you speak Russian or Ukrainian?

…

25 лип. 2023 р. о 12:08 Maqcel ***@***.***> написав(ла): @niskovmaksym <https://github.com/niskovmaksym> Hi I'm currently investigating how to handle this issue can you somehow provide an example repo for it? — Reply to this email directly, view it on GitHub <#9 (comment)>, or unsubscribe <https://github.com/notifications/unsubscribe-auth/AVN5NOY4KNC5FA2D74TGJ5LXR55JRANCNFSM6AAAAAAQBJPZ24>. You are receiving this because you were mentioned.

[Maqcel]

@niskovmaksym Unfortunately no, but if there is a way to see a dummy project with this set up would be a huge help!

[niskovmaksym]

MaterialApp.router( theme: AppThemes.themeLight(context), darkTheme: AppThemes.themeDark(context), routerDelegate: rootRouter.delegate( navigatorObservers: () => [_AppNavigatorObserver()], ), routeInformationProvider: rootRouter.routeInfoProvider(), routeInformationParser: rootRouter.defaultRouteParser(), locale: locale, localizationsDelegates: const [ _S.delegate, SFirstModule.delegate, SSecondModule.delegate, GlobalMaterialLocalizations.delegate, GlobalWidgetsLocalizations.delegate, GlobalCupertinoLocalizations.delegate, ], supportedLocales: _S.delegate.supportedLocales, builder: (context, router) { return Scaffold( body: router!, key: scaffoldKey, ); }), class _S extends S { static const _SDelegate delegate = _SDelegate(); } class _SDelegate extends LocalizationsDelegate<S> { const _SDelegate(); List<Locale> get supportedLocales { return const <Locale>[ Locale.fromSubtags(languageCode: 'en'), Locale.fromSubtags(languageCode: 'de'), Locale.fromSubtags(languageCode: 'es'), Locale.fromSubtags(languageCode: 'pt'), ]; } @OverRide bool isSupported(Locale locale) => _isSupported(locale); @OverRide Future<S> load(Locale locale) { return MultipleLocalizations.load( initializeMessages, locale, (l) => S.load(Locale(l)), setDefaultLocale: true); } @OverRide bool shouldReload(LocalizationsDelegate<S> old) { return false; } bool _isSupported(Locale locale) { for (var supportedLocale in supportedLocales) { if (supportedLocale.languageCode == locale.languageCode) { return true; } } return false; } } Main pubspec  First module pubspec flutter_intl: enabled: true class_name: SFirstModule main_locale: en arb_dir: lib/l10n output_dir: lib/generated use_deferred_loading: false Second module flutter_intl: enabled: true class_name: SSecondModule main_locale: en arb_dir: lib/l10n output_dir: lib/generated use_deferred_loading: false multiple_localization.dart import 'dart:async'; import 'dart:ui'; import 'package:flutter/foundation.dart'; import 'package:intl/intl.dart'; import 'package:intl/message_lookup_by_library.dart'; // this helper if not for direct use, // it's internal, but I haven't find any good way // to implement desired behavior // ignore: implementation_imports import 'package:intl/src/intl_helpers.dart' as intl_private; // ignore: implementation_imports import 'package:intl/src/intl_helpers.dart' show MessageIfAbsent; /// Function for initialize messages. /// It's will be `initializeMessages` from generated code. typedef InitializeMessages = Future<bool> Function(String localeName); /// Use [MultipleLocalizations.load] to implement load function in your localization delegate, /// instead of call `initializeMessages` explicitly. /// /// Example: /// ```dart /// class _AppLocalizationsDelegate /// extends LocalizationsDelegate<AppLocalizations> { /// const _AppLocalizationsDelegate(); /// /// @OverRide /// bool isSupported(Locale locale) { /// return ['en', 'ru'].contains(locale.languageCode); /// } /// /// @OverRide /// Future<AppLocalizations> load(Locale locale) { /// return MultipleLocalizations.load( /// initializeMessages, locale, (l) => AppLocalizations(l), /// setDefaultLocale: true); /// } /// /// @OverRide /// bool shouldReload(LocalizationsDelegate<AppLocalizations> old) { /// return false; /// } /// } ///``` class MultipleLocalizations { static _MultipleLocalizationLookup? _lookup; static _MultipleLocalizationLookup _init(String? fallbackLocale) { assert(intl_private.messageLookup is intl_private.UninitializedLocaleData); final lookup = _MultipleLocalizationLookup(fallbackLocale: fallbackLocale); intl_private.initializeInternalMessageLookup(() => lookup); return lookup; } // only for tests! @VisibleForTesting static void reset() { _lookup = null; intl_private.messageLookup = intl_private.UninitializedLocaleData( 'initializeMessages(<locale>)', null); } /// Load messages for localization and create localization instance. /// /// Use [setDefaultLocale] to set loaded locale as [Intl.defaultLocale]. /// /// Use [fallbackLocale] to set locale which will be used if some key /// not found for current locale. Only first call of [load] will set /// fallback locale, make sure that your app's localization delegate /// added as a first element of the delegates list. /// Also pay attention that if you provide the [fallbackLocale], /// than all messages will be uploaded in memory on the start of application /// in addition to current locale. static Future<T> load<T>(InitializeMessages initializeMessages, Locale locale, FutureOr<T> Function(String locale) builder, {bool setDefaultLocale = false, String? fallbackLocale}) async { final lookup = _lookup ??= _init(fallbackLocale != null ? Intl.canonicalizedLocale(fallbackLocale) : null); final name = locale.toString(); final localeName = Intl.canonicalizedLocale(name); final res = await initializeMessages(localeName).then((_) { if (setDefaultLocale) { Intl.defaultLocale = localeName; } return builder(localeName); }); final fallbackLocaleName = lookup.fallbackLocale; if (fallbackLocaleName != null && fallbackLocaleName != localeName) { // load messages for fallback locale, so it can be used if some key was not found await initializeMessages(fallbackLocaleName); } return res; } } class _MultipleLocalizationLookup implements intl_private.MessageLookup { final Map<Function, CompositeMessageLookup> _lookups = {}; final String? fallbackLocale; _MultipleLocalizationLookup({this.fallbackLocale}); @OverRide void addLocale(String localeName, Function findLocale) { final lookup = _lookups.putIfAbsent( findLocale, () => CompositeMessageLookup(), ); lookup.addLocale(localeName, findLocale); } @OverRide String? lookupMessage(String? messageStr, String? locale, String? name, List<Object>? args, String? meaning, {MessageIfAbsent? ifAbsent}) { for (final lookup in _lookups.values) { var isAbsent = false; final res = lookup.lookupMessage(messageStr, locale, name, args, meaning, ifAbsent: (s, a) { isAbsent = true; return ''; }); if (!isAbsent) return res; } // TODO: может тут Intl.canonicalizedLocale(fallbackLocale)? if (locale != fallbackLocale) { return lookupMessage(messageStr, fallbackLocale, name, args, meaning, ifAbsent: ifAbsent); } else { return ifAbsent == null ? messageStr : ifAbsent(messageStr, args); } } }

…

25 лип. 2023 р. о 14:20 Maqcel ***@***.***> написав(ла): Unfortunately no, but if there is a way to see a dummy project with this set up would be a huge help! — Reply to this email directly, view it on GitHub <#9 (comment)>, or unsubscribe <https://github.com/notifications/unsubscribe-auth/AVN5NO7Y5NMNSOULMW3WLU3XR6MWTANCNFSM6AAAAAAQBJPZ24>. You are receiving this because you were mentioned.

[Maqcel]

Thanks wish it will help!

[niskovmaksym]

Good luck! The rest of the files are generated after the code generation command.

…

25 лип. 2023 р. о 15:09 Maqcel ***@***.***> написав(ла): Thanks wish it will help! — Reply to this email directly, view it on GitHub <#9 (comment)>, or unsubscribe <https://github.com/notifications/unsubscribe-auth/AVN5NOZSIFTXQ63VJ6TA6H3XR6SM3ANCNFSM6AAAAAAQBJPZ24>. You are receiving this because you were mentioned.

[banool]

Hey @Maqcel, did you ever find a way to make this work? I like the auto generated localizations files but it seems like it's impossible to use multiple of them.

[JamesMcIntosh]

It was broken in intl 0.19.x see dart-lang/i18n#783 0.20.x contains the fix.

Make a AppLocalizationDelegate for each projects generated messages you want to use.

import 'package:flutter/rendering.dart';
import 'package:multiple_localization/multiple_localization.dart';
import 'package:myapp/generated/intl/messages_all.dart';
import 'package:myapp/generated/l10n.dart';

class R extends AppLocalizationDelegate {
  static const R delegate = R();

  static S instance = S();

  const R();

  @override
  Future<S> load(Locale locale) async {
    return MultipleLocalizations.load(
      initializeMessages,
      locale,
      (l) => instance,
      setDefaultLocale: true,
    );
  }
}

The add the list of delegates in your MaterialApp()

MaterialApp(
    localizationsDelegates: const [
        R.delegate,
        UI.delegate,
        Module1.delegate,
        ...
        GlobalWidgetsLocalizations.delegate,
      ],
)