Celest Backend

Celest is a backend framework for Dart and Flutter.

If your app uses Async Redux and your server uses Celest, you can add the Dart-only core package async_redux_core to your server side.

Now, if you throw a UserException in your backend code, that exception will automatically be thrown in the frontend. As long as the Celest cloud function is called inside an action, and you have set up the UserExceptionDialog (See here), Async Redux will display the exception message to the user in a dialog (or other UI element that you can customize).

Note: This can also be used with package i18n_extension_core to make sure the error message gets translated to the user's language. For example: UserException('The password you typed is invalid'.i18n); in the backend, will reach the frontend already translated as UserException('La contraseña que ingresaste no es válida') if the user device is in Spanish.