yadis.pl -- Yadis discovery

See also

- http://en.wikipedia.org/wiki/Yadis

 xrds_dom(+Id, -XRDS_DOM) is det

True when XRDS_DOM is a parsed XML document for the given resource.

 xid_normalize(+OpenID, -URL) is det[private]

Translate the user-specified OpenID agent into a URL. This follows appendix A.1. (Normalization), RFC3986).

To be done

- This does not implement XRI identifiers.

 xrds_location(+Id, -XRDSLocation) is semidet

Discover the location of the XRDS document from the given Id.

 xrds_load(+XRDSLocation, -XRDS_DOM) is det[private]

Parse the XRDS document at XRDSLocation.

 ssl_verify(+SSL, +ProblemCert, +AllCerts, +FirstCert, +Error)[private]

Accept all certificates.

 html_head_dom(+Stream, -HeadDOM) is semidet[private]

Extract the HTML head content from the given stream. Does not parse the remainder of the document.

 xrds_specified_location(+URL, -XRDSLocation) is nondet[multifile]

Hook that allows for specifying locations of XRDS documents. For example, Google does not reply to Yadis discovery messages. We can fake it does using:

yadis:xrds_specified_location('http://google.com/',
                              'https://www.google.com/accounts/o8/id').

If this hook succeeds with XRDSLocation bound to - (minus), we assume there is no XRDS document associated to URL. This can be used to avoid retrieving misleading or broken XRDS documents.