flutter-localizations-plus

name	flutter_localizations_plus
description	Use when coding with flutter_localizations_plus: JSON locale assets, Translations.support, LocalizationsPlusDelegate, FallbackCupertinoLocalizationsDelegate, context.i18n/l10n, and runtime language switching.

flutter_localizations_plus Agent Context

Use this package for JSON-backed Flutter localization with sprintf-style interpolation and runtime language switching.

Imports

import 'package:flutter_localizations_plus/flutter_localizations_plus.dart';
import 'package:flutter_localizations_plus/localization.dart';
import 'package:flutter_localizations_plus/locale_config.dart';

Assets

Locale files live under locales/ and must be declared in pubspec.yaml.

flutter:
  assets:
    - locales/

Locale file names use ${languageCode}_${localeCode}.json, for example en_US.json.

{
  "@@locale": "en_US",
  "local_time_caption": "Current local time: %s",
  "flight_broadcast_test": "Hello %s from %s."
}

App Setup

Call Translations.support(...) before building the app so supportedLocales is populated.

Translations.support(
  [
    Localization.en_US,
    Localization.zh_Hans,
    Localization.fr_CA,
    Localization.pt_BR,
  ],
  selected: Platform.localeName,
  fallback: Localization.en_US,
);

MaterialApp(
  supportedLocales: Translations.supportedLocales,
  localizationsDelegates: const [
    LocalizationsPlusDelegate(),
    FallbackCupertinoLocalizationsDelegate(),
  ],
  home: const Home(),
);

Reading Text

Translations.of(context).text("local_time_caption", DateTime.now());
Translations.of(context).text(
  "flight_broadcast_test",
  ["flutter_localizations_plus", "pub.dev"],
);

context.i18n("local_time_caption", DateTime.now());
context.l10n("flight_broadcast_test", ["flutter_localizations_plus", "pub.dev"]);

Runtime Language Switching

final allSupported = Translations.allSupported;
await Translations.changeLanguage(allSupported[index].locale);

Notes for Agents

• Do not invent ARB APIs; this package uses JSON files and Translations.
• Use LocalizationsPlusDelegate and FallbackCupertinoLocalizationsDelegate.
• Use sprintf-style %s placeholders and pass a single value or a list of values.
• Keep locale constants from Localization, e.g. Localization.en_US.