WordPress Plugin: seeAlso’s

FOAF, RDF, Release, WordPress

What is now several weeks ago, Christoph Görn hacked a bit on my FOAF Output plugin, and asked for seeAlso links to be included. Short of the mythical WordPress triple store (factory?) I couldn’t see a better way to do it than building on the concept from the Semantic Visits add-on: Using the link manager.

I challenged Danny Ayers to write the plugin/add-on, but he’s been busy lately, with the RSS book and all, so here it is, the seeAlso’s Plugin (view source). While I was at it, I also fixed a few buglets in the FOAF Output Plugin and added trust ratings for friends and bio:olb.

The current version is 1.0 (this blog entry will serve as a changelog).

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Visit Revisited

OWL, Vocabularies, WordPress

A few days ago, Norman Walsh was kind enough to let me know that there was something wrong with the way I had put together the visit vocabulary.

It turned out that I had mixed together some URIs while surfing around the DAML vocabularies, and the URIs I used to identify each of the states were wrong — the right ontology is http://www.daml.ri.cmu.edu/ont/USRegionState.daml.

The visit vocabulary has been updated to reflect this, and the WordPress plugin Semantic Visits has been fixed, you should upgrade if at all possible.

In addition to the fixes, it has been clarified that the right ISO 3166 country code for the United Kingdom is “GB”. This warranted a fix (or more precisely an addition) in the image generation code at MyWorld66, and Douwe Osinga was quick to respond — it now accepts “GB” as well as “UK” (for backwards compatibility reasons only, use “GB” from now on), thanks!

While I was twiddling, I added support for Canadian provinces — also supported by MyWorld66’s Visited Canadian Provinces and a DAML ontology for Canadian States and Teritories, for those that have had the privilege of visiting those parts of the world.

This last part turned out to be a little harder than expected, as the Canadian regions are divided into states and territories, and that required some investigations into OWL — I think I got it right, but if not you’ll likely see yet another correction soon…

Also, it turned out that there was an issue with the terms used to indicate the code, name, and other state properties — the terms are defined in the general DAML State Ontology as e.g. http://www.daml.ri.cmu.edu/ont/State.daml#code, but in the DAML US Region and State Ontology and the DAML ontology for Canadian States and Teritories they are used as e.g. http://www.daml.ri.cmu.edu/ont/CanadianState.daml#code.

I’m still not sure whether the error is because of a typo with regards to the default namespace declaration, or if it’s a misunderstanding of the semantics of owl:imports (actually daml:imports). In any case, I have decided not to propagate the error, so the WordPress Plugin and the vocabulary documentation uses the properties that are defined — but not used until now.

“They Rule” as RDF

FOAF, RDF

Yesterday Dan Brickley reported success on getting Josh On to release “They Rule” data. This has been a somewhat long standing goal for the FOAFCorp effort, and According to Josh, who created it, the data is free.

Dan asked for conversion into RDF/XML, so here it is — created by theyrule2ntriples.pl, which was inspired by Dan’s own scripts from last year: “They Rule” 2004 as RDF/XML (gzipped, 175k) or “They Rule” 2004 as NTriples (gzipped, 168k)

I’m sure Jim Ley will have this loaded into foafnaut before long, for everyone to browse…

WordPress Plugin: Semantic Visits

FOAF Explorer, Release, Travelling, Vocabularies, WordPress

When I came back from Madrid, after the Image Decription workshop, a few days in the city, and a hefty party in Getafe, I realised I could add another country to my list of visits.

The nice folks at World66 have created a nice interface for generating an image with visited countries highlighted, but while it would be easy to check a few boxes and copy the code to somewhere on my blog pages, that wouldn’t make it possible for the semantic web to figure out where I’ve been. For that reason, I decided to mint a set of vocabulary terms for visits according to Norm Walsh’s country counting rules, collected in the visit vocabulary, and have WordPress output the information in my FOAF profile – thanks to the extensibility of my FOAF Output Plugin. Of course, the FOAF Explorer now also understands these terms, displaying maps of the world, Canada and USA when appropriate — see for yourself!

Thus, here is a new plugin, the Semantic Visits Plugin (view source).

The current version is 1.1.

Changes since 1.0:
  • Added visits to Canadian regions.
  • Fixed “wrong” code/name/etc. properties.
  • The URIs for US states are now correct, pointing at the http://www.daml.ri.cmu.edu/ont/USRegionState.daml ontology containing state definitions instead of http://www.daml.ri.cmu.edu/ont/State.daml which only contains classes and properties.

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WordPress Plugin: FOAF Output

FOAF, Release, RSS, WordPress

A while ago I hacked WordPres into emitting FOAF, but even though it worked fine, the amount of WordPress-tweaking wasn’t for the faint of heart.

Since then, I have looked a little deeper into WordPress, and now it’s finally ready: The FOAF Output Plugin (view source).

Note: If you want to try running this with WordPress > 1.2, please fix the .htaccess rewrite rule for the author pages like this, otherwise the FOAF file will result in a 404:

RewriteRule ^author/([^/].+)/?$ /<SITEHOME>/index.php?author_name=$1 [QSA,L]

The current version is 1.17 (released 2005-08-31).

Changes since 1.16:
  • Fixed errant line breaks in links.
  • Added generator comment to RSS output.
Changes since 1.15:
  • Added oneline bio on profile page, not HTML-escaped.
  • Added link to RSS channel from author list.
  • Tweaked prefix usage for namespaces.
Changes since 1.14:
  • Added check for array being returned from get_the_category().
  • Added check for get_Lat and get_Long for > 1.2 compatibility.
Changes since 1.13:
  • Fixed category/interest when no categories were found.
  • Changed skos:externalID to dc:identifier.
  • Updated SKOS generation with SKOS extensions vocabulary.
  • Fixed generation of author list URI.
Changes since 1.12:
  • Changed a wrong foaf:made to foaf:page, caught by Ian Davis.
  • Fixed erroneous output of homepage URI on profile page.
  • Fixed a problem with statements being added to Atom feeds, thanks Danny/Sam.
Changes since 1.11:
  • Added blog-wide FOAF output (blogroll) with seeAlso’s to authors’ individual files (example).
Changes since 1.10:
  • Added SKOS output (example) and enhanced RSS output.
  • Added document level RDF/XML API hook, foaf_output_profile_rdf_document, to allow for additional properties by add-ons, e.g. generator information.
  • Fixed possible missing namespace declarations for dcterms in RSS/Atom.
  • Tweaked initialisation code to increase reusability.
Changes since 1.9:
  • Fixed limited interest generation for HTML profile page.
  • Multiple URIs per interest is now handled correctly (if separated by whitespace).
  • Only categories with posts by author are deemed “interesting”.
  • Added bio:olb per B.K. DeLong’s suggestion.
  • Added trust ratings for friends.
Changes since 1.8:
  • Renamed foaf_output_the_date to get_foaf_output_profile_page to better reflect the functionality.
Changes since 1.7:
  • Improved identification of “active” author / user.
  • Now really only shows profile on first archive page, even in paged mode.

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