Question

How to explicitly set django_language in Django session?

Thanks a lot…

Answer 1

If you want your users to be able to specify language, make sure that LocaleMiddleware is enabled:

MIDDLEWARE_CLASSES = (
   ...
   'django.middleware.locale.LocaleMiddleware',
   ...
)

Then Django will look for the user’s language preference in that order (see get_language_from_request in trans_real.py):

1. in request.path_info, if i18n_patterns are used
2. request.session[settings.LANGUAGE_SESSION_KEY] (DEPRECATED in Django 3.0, removed in Django 4.0)
3. request.COOKIES[settings.LANGUAGE_COOKIE_NAME]
4. every language in request.META['HTTP_ACCEPT_LANGUAGE'], until accepted one is found
5. settings.LANGUAGE_CODE.

As of Django 4.0

The most straightforward way to set language explicitly in Django session is to activate and set the cookie, see the docs:

from django.conf import settings
from django.http import HttpResponse
from django.utils import translation

user_language = 'fr'  # example
translation.activate(user_language)

# persist using the cookie
response = HttpResponse(...)
response.set_cookie(settings.LANGUAGE_COOKIE_NAME, user_language)

Before Django 4.0

The most straightforward way to set language explicitly in Django session is to rewrite request.session[settings.LANGUAGE_SESSION_KEY]:

def someview (request):
    ...
    request.session[settings.LANGUAGE_SESSION_KEY] = 'en'
    ...