[foaf-dev] proposal for foaf:openid property
danbri at danbri.org
Sun Jun 17 00:38:26 BST 2007
Draft in progress. Anyone object to this going into the spec?
openid - An OpenID for an Agent.
OWL Type: An InverseFunctionalProperty (uniquely identifying property)
A foaf:openid is a property of a foaf:Agent that associates it with a
document that can be used as an indirect identifier in the manner of the
OpenID "Identity URL". As the OpenID 1.1 specification notes, OpenID
itself"does not provide any mechanism to exchange profile information,
though Consumers of an Identity can learn more about an End User from
any public, semantically interesting documents linked thereunder (FOAF,
RSS, Atom, vCARD, etc.)". In this way, FOAF and OpenID complement each
other; neither provides a stand-alone approach to online "trust", but
combined they can address interesting parts of this larger problem space.
The foaf:openid property is "inverse functional", meaning that anything
that is the foaf:openid of something, is the foaf:openid of no more than
one thing. FOAF is agnostic as to whether there are (according to the
relevant OpenID specifications) OpenID URIs that are equally associated
with multiple Agents. FOAF offers sub-classes of Agent, ie.
foaf:Organization and foaf:Group, that allow for such scenarios to be
consistent with the notion that any foaf:openid is the foaf:openid of
just one foaf:Agent.
FOAF does not mandate any particular URI scheme for use as foaf:openid
values. The OpenID 1.1 specification includes a delegation model that is
often used to allow a weblog or homepage document to also serve in
OpenID authentication via "link rel" HTML markup. This deployment model
provides a convenient connection to FOAF, since a similar technique is
used for FOAF autodiscovery in HTML. A single document can, for example,
serve both as a homepage and an OpenID identity URL.
More information about the foaf-dev