rdf 6.x-1.0-alpha4

A fourth alpha-quality development snapshot for Drupal 6.x.

Changes since 6.x-1.0-alpha3:

• Renamed vendor/arc2 directory to vendor/arc (#273804: ARC2 library installation path update by robertDouglass).
• Extended the RDF DB tuple store with the statement creator's user ID and the creation timestamp.
• Deprecated rdf_uriref() in favor of rdf_uri().
• Removed spurious, non-Drupalesque PHPDoc file headers.
• Implemented export/import of RDFized Drupal settings.
• Added descriptions for the admin/content/rdf and admin/settings/rdf/contexts screens.
• Minor cleanup for stricter adherence to the Drupal coding standards.
• Replaced all instances of require_once() with module_load_include().
• Added maintenance settings to prevent/merge duplicate RDF statements and purge unused resource URIs on cron runs.
• Added input validation to rdf_qname_to_uri().
• Implemented a Views plugin that generates an RSS 1.0-compatible RDF feed from any node-based view.
• Added RSS 1.0 to the list of always-available default namespaces.
• Added new API functions rdf_seq(), rdf_bag(), rdf_alt().
• Added new API classes RDF_Collection, RDF_Seq, RDF_Bag, RDF_Alt.
• Fixed bugs in blank node handling.
• Corrected and improved the output of the RDF/XML serializer.
• Corrected negligence in rdf_bag() and rdf_alt().
• Improvement to rdf_serialize_ntriples().
• Implemented hook_form_alter() for CCK field mappings in CCK 6.x-2.0-rc10.
• Implemented direct support for RDF-mapped CCK fields in the RDF Views row plugin.
• Implemented URI/CURIE validation and CURIE expansion for CCK/profile field mappings.
• Implemented join points invoking hook_rdf_views_feed(), hook_rdf_views_feed_channel(), and hook_rdf_views_feed_item().
• Added support for defining namespace prefixes for URNs; fixed rdf_is_valid_urn() somewhat.
• Added new API function rdf_register_namespace().
• Implemented support for geo:lat and geo:long (based on the Location module) in the Views plugin.
• Terminate Views plugin feed output with die() to prevent leading whitespace due to e.g. theming problems.
• Updated unit tests for Simpletest 2.x compatibility.
• Bug fixes for Views RDF feeds: output dc:date in ISO 8601 format; don't output empty properties.
• Added API functions rdf_is_valid_datetime(), rdf_val_to_str() and rdf_str_to_val().
• Implemented hook_feedapi_mapper() for Feed Element Mapper integration.
• Implemented a new admin/settings/rdf/mappings screen for displaying a summary of defined mappings between Drupal data and RDF classes/properties.
• Don't add distinct RDF autodiscovery headers for every node when in a view/feed listing.
• Added dc:subject properties for nodes' taxonomy terms in the Views feed plugin.
• Fine-tuned RDF feed items: be more picky about including the rss:description property; make dc:date a datatyped property; ensure that the feed index is created using the nodes' internal URLs, not their aliases.
• Cast CCK date field values to RDF datatyped literals when outputting RDF feed properties.
• Improved input validation of the various RDF mapping fields; fixed the saving of content type RDF mappings (#279244: Saving content type RDF mappings fails).

Full details at http://drupal.org/project/cvs/182305

Note: This is experimental software meant for advanced users; assume nothing works, and you may be pleasantly surprised. And when it breaks, you get to keep both pieces.