firebase-ui-localizations.md

Firebase UI Localizations

Firebase UI for Flutter supports localization, so every single label can be customized.

Installation

dependencies:
  flutter_localizations:
    sdk: flutter
  firebase_ui_localizations: ^1.2.0

Usage

If your app supports only a single language, and you want to override labels – you will need to provide a custom class that implements one of the exposed localizations.

For example, we could override the Spanish localization class and customize the email and password labels:

import 'package:flutter_localizations/flutter_localizations.dart';
import 'package:firebase_ui_localizations/firebase_ui_localizations.dart';

// EsLocalizations is a class that provides Spanish labels. We override it here:
class LabelOverrides extends EsLocalizations {
  const LabelOverrides();

  @override
  String get emailInputLabel => 'Enter your email';

  @override
  String get passwordInputLabel => 'Enter your password';
}

Once created, pass the instance of LabelOverrides to the localizationsDelegates list in your MaterialApp/CupertinoApp:

class MyApp extends StatelessWidget {
  @override
  Widget build(BuildContext context) {
    return MaterialApp(
      localizationsDelegates: [
        // Creates an instance of FirebaseUILocalizationDelegate with overridden labels
        FirebaseUILocalizations.withDefaultOverrides(const LabelOverrides()),

        // Delegates below take care of built-in flutter widgets
        GlobalMaterialLocalizations.delegate,
        GlobalWidgetsLocalizations.delegate,

        // This delegate is required to provide the labels that are not overridden by LabelOverrides
        FirebaseUILocalizations.delegate,
      ],
      // ...
    );
  }
}

If you need to support multiple languages – follow the official Flutter localization guide and make sure that your custom delegate extends LocalizationsDelegate<FirebaseUILocalizations>.

Note: check out API reference to learn what labels are used by specific widgets