Localization

Generating New Locale Messages

When adding new strings to be localized, update intl_en_US.arb, which is used by this project as the template. When creating new entries, they have to be in the following format:

  "dartGetterVariableName": "english translation of the message",
  "@dartGetterVariableName": {
    "description": "description that the localizations delegate will use."
  },

In this example, dartGetterVariableName should be the Dart method/property name that you will be using in your localizations delegate.

After adding the new message in intl_en_US.arb, it can be used in the app by regenerating the GalleryLocalizations delegate and the messages_*.dart files. This allows use of the English message through your localizations delegate in the application code immediately without having to wait for the translations to be completed.

How to Generate GalleryLocalizations with Grinder

From the samples/gallery/gallery/ directory:

  1. Make sure you have grinder installed by running flutter pub get.
  2. Then run flutter pub run grinder l10n to generate GalleryLocalizations.

For more details on what flutter pub run grinder l10n runs, you can read below under How to Generate GalleryLocalizations with l10n scripts. The current supported locales list is sorted alphabetically. This means that after running the script, you have to update gallery_localizations.dart and move the en_US locale to the top of the list.

How to Generate GalleryLocalizations with l10n scripts

To generate GalleryLocalizations, from samples/gallery/gallery/ run:

dart ${YOUR_FLUTTER_PATH}/dev/tools/localization/bin/gen_l10n.dart \
    --template-arb-file=intl_en_US.arb \
    --output-localization-file=gallery_localizations.dart \
    --output-class=GalleryLocalizations

From samples/gallery/gallery/, run dart ../l10n_cli/bin/main.dart, which will generate intl_en_US.xml. This will be used by the internal translation console to generate messages in the different locales.

Run the formatter to make the Flutter analyzer happy:

flutter format .

Generating New Locale Arb Files

Use the internal tool to create the intl_<locale>.arb files once the translations are ready.

Generating Flutter Localization Files

If new translations are ready and the intl_<locale>.arb files are already available, run the following commands to generate all necessary messages_<locale>.dart files and the localizations_delegate.dart file:

flutter pub run grinder l10n

which is equal to

dart ${YOUR_FLUTTER_PATH}/dev/tools/localization/bin/gen_l10n.dart \
    --template-arb-file=intl_en_US.arb \
    --output-localization-file=gallery_localizations.dart \
    --output-class=GalleryLocalizations

flutter format .

This ensures the generated .dart files updated with the latest translations.