Client language preference

Client browsers can specify their language preferences through the HTTP Accept-Language header. For example,

Accept-Language: fr,de;q=0.3,en;q=0.7

This header indicates a preference for French, English and German in that order. An application can retrieve this header from the env object and parse it. However, the recommended method is to invoke the accept_languages method on the request object. This will return the list of preferred languages in priority order. For example, for the above header this method will return the list {fr en de}.