Adding "preferred_language" property to "HttpRequest" object

[Ruslan Semagin]

Sometimes it is useful to get the client's preferred language from the request and then pass it somewhere, for example, apply a filter to fetch data.
Therefore, it is useful to access this property in the object.

@property
def preferred_language(self):
    """Returns the client's language in order of priority from the "Accept-Language" header"""
    languages = [_.strip() for _ in self.headers.get('Accept-Language', '*').split(',')]
    return languages[0].split(';')[0]

[Nick Pope]

So unfortunately this is not as simple as what you have proposed for a number of reasons:

• The q value for the priority of entries in the header should be taken into account ​as mentioned by Keryn.
• The special * value shouldn't be returned as it isn't a valid language.
• The value in Accept-Language may not be the user's "preferred" language. It is just the languages that the client is configured to accept.

See ​https://developer.mozilla.org/en-US/docs/Web/HTTP/Headers/Accept-Language for more details.

The good news is that Django has already implemented this and taken everything into consideration. Check out ​get_language_from_request().

Obviously this restricts the returned languages to those that are available in settings.LANGUAGES.

If you really need to have the "preferred" and unadulterated value from the Accept-Language header, you could use the parse_accept_lang_header() function, but beware that this is an undocumented, private function.