[OpenID] AX schema namespace URL, and RDF metadata

[Peter Williams]

In http://www.ldap.com/1/commentary/wahl/20070510_02.shtml, you note:
 
    "Note #2: OpenID AX doesn't (yet) provide a metadata query, however AX attribute types are HTTP/HTTPS URIs, which point to RDF definitions. "
 
We ran with this notion (and some others, in which the requested attribute names are URI-encoded queries). Based on the TargetResource of the websso endpoint, once websso is complete the AX requestor builds RDF classes on the fly from a metadata repository that publishes attributes, object classes and attribute types/syntaxes .. .for one or more AX namespace URLs locally associated with that target. The sets of classes are locally expressed, in RDFS and a touch of owl (for enumerated types).
 
Even if the webapp does not use any of those namespace in its (legacy) code, a local inference rulebase rewrite the AX names from the namesets into the legacy name/types/classes, acting rather like an RP-side ws-federation STS . The legacy code knows nothing of this: its all hidden behind a jdbc interface to the RDF data-federation server.
 
This all fits nicely with SP-centric federations, which control the core standards of the webapp and interface with lots of IDPs, all competing.