flutter/packages/flutter_localizations

Flutter Framework localizations

This package contains the localizations used by the Flutter framework itself.

See the localization README for more detailed information about the localizations themselves.

Adding a new string to localizations

If you (someone contributing to the Flutter framework) want to add a new string to the MaterialLocalizations, WidgetsLocalizations or the CupertinoLocalizations objects (e.g. because you've added a new widget and it has a tooltip), follow these steps (these instructions are for MaterialLocalizations, but apply equally to CupertinoLocalizations and WidgetsLocalizations, with appropriate name substitutions):

1. Add the new getter to the localizations class MaterialLocalizations, in flutter_localizations/lib/src/material_localizations.dart.

2. Implement a default value in DefaultMaterialLocalizations in flutter_localizations/lib/src/material_localizations.dart

3. Add a test to test/material/localizations_test.dart that verifies that this new value is implemented.

4. Update the flutter_localizations package. To add a new string to the flutter_localizations package, you must first add it to the English translations (lib/src/l10n/material_en.arb), including a description.

   Then you need to add new entries for the string to all of the other language locale files by running:

   dart dev/tools/localization/bin/gen_missing_localizations.dart
   

   Which will copy the English strings into the other locales as placeholders until they can be translated.

   Finally you need to re-generate lib/src/l10n/localizations.dart by running:

   dart dev/tools/localization/bin/gen_localizations.dart --overwrite
   

   There is a localization README file with further information in the lib/src/l10n/ directory.

5. If you are a Google employee, you should then also follow the instructions at go/flutter-l10n. If you're not, don't worry about it.

Updating an existing string

If you or someone contributing to the Flutter framework wants to modify an existing string in the MaterialLocalizations objects, follow these steps:

1. Modify the default value of the relevant getter(s) in DefaultMaterialLocalizations below.

2. Update the flutter_localizations package. Modify the out-of-date English strings in lib/src/l10n/material_en.arb.

   You also need to re-generate lib/src/l10n/localizations.dart by running:

   dart dev/tools/localization/bin/gen_localizations.dart --overwrite
   

   This script may result in your updated getters being created in newer locales and set to the old value of the strings. This is to be expected. Leave them as they were generated, and they will be picked up for translation.

   There is a localization README file with further information in the lib/src/l10n/ directory.

3. If you are a Google employee, you should then also follow the instructions at go/flutter-l10n. If you're not, don't worry about it.