Configuration

To get started all you need to do is to instanciate a Babel object after configuring the application:

.. code-block:: python

from quart import Quart from quart_babel import Babel

app = Quart(__name__) babel = Babel(app)

You can also use the factory method of initializing extensions:

babel.init_app(app)

To disable jinja support, include configure_jinja=False in the Babel constructor call. The babel object itself can be used to configure the babel support further. Babel has the following configuration values that can be used to change some internal defaults:

Configuration Variables

Variable	Type	Default	Description
BABEL_DEFAULT_LOCALE	str	'en_US'	The default locale to use if no locale selector is registered.
BABEL_DEFAULT_TIMEZONE	str	'UTC'	The timezone to use for user facing dates.
BABEL_DOMAIN	str | list[str]	"messages"	The default translation domain(s).
BABEL_TRANSLATION_DIRECTORIES	str | list[str]	"translations"	The directories where translations can be found.

For more complex applications you might want to have multiple applications for different users which is where selector functions come in handy. The first time the babel extension needs the locale (locale code/ID) of the current user it will call a localeselector() function, and the first time the timezone is needed it will call a timezoneselector() function.

If any of these methods return None the extension will automatically fall back to what’s in the config. Furthermore for efficiency that function is called only once and the return value then cached. If you need to switch the language between a request, you can refresh() the cache.

Example selector functions:

.. code-block:: python

from quart import Quart, g, request

def get_locale():

# if a user is logged in, use the locale from the user settings user = getattr(g, ‘user’, None) if user is not None:

return user.locale

# otherwise try to guess the language from the user accept # header the browser transmits. We support de/fr/en in this # example. The best match wins. return request.accept_languages.best_match([‘de’, ‘fr’, ‘en’])

def get_timezone():

user = getattr(g, ‘user’, None) if user is not None:

return user.timezone

app = Quart(__name__) babel = Babel(app, locale_selector=get_locale, timezone_selector=get_timezone)

The example above assumes that the current user is stored on the quart.g object.