A Content Repository API for Rich, Semantic Web Applications?

[by Chimezie Ogbuji]

I've been working with roll-your-own content repositories long enough to know that open standards are long overdue.

The slides for my Semantic Technology Conference 2007 session are up: "Tools for the Next Generation of CMS: XML, RDF, & GRDDL" (Open Office) and (Power point)

This afternoon, I merged documentation of the 4Suite repository from old bits (and some new) into a Wiki that I hope to contribute to (every now and then).
I think there is plenty of mature, supporting material upon which a canon of best practices for XML/RDF CMSes can be written, with normative dependencies on:

  • XProc
  • Architecture of the World Wide Web, Volume One
  • URI RFCs
  • Rich Web Application Backplane
  • XML / XML Base / XML Infoset
  • RDDL
  • XHTML 1.0
  • SPARQL / Versa (RDF querying)
  • XPath 2.0 (JSR 283 restriction) with 1.0 'fallback'
  • HTTP 1.0/1.1, ACL-based HTTP Basic / Digest authentication, and a convention for Web-based XSLT invokation
  • Document/graph-level ACL granularity

The things that are missing:

  • RDF equivalent of DOM Level 3 (transactional, named graphs, connection management, triple patterns, ... ) with events.
  • A mature RIF (there is always SWRL, Notation 3, and DLP) as a framework for SW expert systems (and sentient resource management)
  • A RESTful service description to complement the current WSDL/SOAP one

For a RESTful service description, RDF Forms can be employed to describe transport semantics (to help with Agent autonomy), or a mapping to the Atom Publishing Protocol (and a thus a subset of GData) can be written.

In my session, I emphasized how closely JSR 283 overlaps with the 4Suite Repository API.

The delta between them mostly has to do with RDF, other additional XML processing specifications (XUpdate, XInclude, etc.), ACL-based HTTP authentication (basic, and sessions), HTTP/XSLT bindings, and other miscellaneous bells and whistles

Chimezie Ogbuji

via Copia