preferences.pl -- User preference handling
This module defines access to user-preferences. The API for the
preference system is based on RDF. This allows for using the RDF-store
for storing preferences, typically using the OpenID URI as subject. The
actual storage infrastructure must be implemented using hooks in the
cliopatria module: cliopatria:user_preference_db/2 and
cliopatria:user_preference_default/2.
Preferences are defines in the RDF namespace with prefix user, which
expands to:
http://www.swi-prolog.org/cliopatria/user/
- user_preference(?Preference:resource, ?Value:object) is nondet
- True if Preference has Value. Preference and Value use the RDF
data-representation. E.g.,
?- user_preference(user:lang, literal(Lang)) Lang = en