Since the modeltranslation mechanism relies on the current language as it
is returned by the get_language
function care must be taken when accessing
translated fields outside a view function.
Within a view function the language is set by Django based on a flexible model described at How Django discovers language preference which is normally used only by Django's static translation system.
When a translated field is accessed in a view function or in a template, it
uses the django.utils.translation.get_language
function to determine the
current language and return the appropriate value.
Outside a view (or a template), i.e. in normal Python code, a call to the
get_language
function still returns a value, but it might not what you
expect. Since no request is involved, Django's machinery for discovering the
user's preferred language is not activated. For this reason modeltranslation
adds a thin wrapper around the function which guarantees that the returned
language is listed in the LANGUAGES
setting.
The unittests use the django.utils.translation.trans_real
functions to
activate and deactive a specific language outside a view function.