Localization

Localization (l10n) is done through the Flutter intl package. This page shows how to create localized entries, parametrize them and access them in code after generating localization files. Also, some project-individual localization features are shown.

Create and Access Localizations

Localization ARB files can be found in lib/l10n/ folder. Localized entries are created as key-value-pairs, looking like this:

"authLoginTitle": "Login",

After localizations have been edited, corresponding Dart files have to be re-generated using the following command:

dart run intl_utils:generate

A localized entry is loaded using S.of(context), suffixing the name of the key like that:

Text(S.of(context).authLoginTitle)

One can add parameters to a localized entry by writing a parameter in curly braces. In such cases, a descriptive localization entry should be created, emphasizing the parameter's meaning:

  "authLoginFailed": "Login failed. (Status {{status}})",
  "@authLoginFailed": {
    "description": "status: HTTP status code of the login"
  }

Parameters are passed to the key when accessing the localized item:

Text(S.of(context).authLoginFailed(e.toString()))

LocaleController

The LocaleController is the central class for handling all logical operations related to localization within the app. The controller can be accessed anytime using the widget tree over the current BuildContext like so:

context.read<LocaleController>()

There are some interesting data you may access:

locale: Returns the current Locale object, reflecting the selected language.
currentLocaleIsGerman: Utility to quickly access whether the user currently has a German language selection entry.
translations: Loads current localized entries without the need of BuildContext. This can be useful when accessing localizations in static repositories.

TranslatedText

TranslatedText is a utility model reflecting API-sent entries which are available in multiple languages. Each TranslatedText therefore stores any amount of Translation-entries, each reflecting a specific translation text with its corresponding languageCode.

TranslatedText offers the following utilities:

translations: The full list of all Translation items.
getTextForLanguageCode: Returns the relevant translation for a given locale code. If there is no fitting translation, the English localization is returned. If there is no translation at all, returns null.
getTextForControllerLanguage: Same as getTextForLanguageCode, but considers the locale currently set in the LocaleController.
getTextForCurrentLanguage: Same as getTextForControllerLanguage, but loads the LocaleController through the passed BuildContext.
german: Same as getTextForLanguageCode, but tries to load the German entry.
english: Same as getTextForLanguageCode, but tries to load the English entry.

There also is a service model implementation for the HSMWmobil app API called AppApiTranslatedText with a fitting fromJson constructor.

Last modified: 14 December 2025