[wiki-standards] Wiki Profile Vocabulary

Fri Jul 6 15:03:09 CEST 2007

Hi all,

Thanks to everyone who attended Tuesday's IRC meeting
(http://wikiohana.net/cgi-bin/wiki.pl/IrcMeetingJuly2007) - it was
productive. For those who weren't there, I was inviting discussion on
a project I've been working on called the Wiki Profile Vocabulary,
which is essentially an RDF vocabulary for describing wikis and
aspects of wikis. (The idea was originally suggested by Ward; thanks.)
You can find the latest version at
http://wikirdf.org/vocabulary/profile/ . There's also an article I
wrote about what a "profile document" is and how to make one, at
http://wikirdf.org/docs/creating-wiki-profiles.html .

What I'm hoping that wiki authors will do is add support for producing
these profile documents to their wiki engines, complete with
autodiscovery tags in the <head> sections of their HTML pages, in
order for robots and other mechanisms to find the information. In
theory, it would be possible to write code to automatically generate
sister site links from one wiki to another, just by entering the URI
of the other wiki.

Two main points were discussed:

The current version of the spec has a naive expectation that wiki URIs
are roughly of the form
http://example.com/scriptname?args=whatever;page=[page name here].
However some wiki engines use URIs of the form
http://example.com/scriptname/[page name here]/args. Chris Dent
suggested using URI Templates
(http://bitworking.org/projects/URI-Templates/) to define the form of
URIs, and this was generally agreed to be a good idea.

The other point was how to specify an autodiscovery method in page
HTML that points to a wiki's profile document. Suggestions were (note,
examples only; your engine's URI for producing a profile doesn't
matter):

A la Dublin Core (suggested by Reini Urban):
<meta name="wiki.profile" type="application/rdf+xml"
link="/wiki?action=profile">

A la FOAF (http://rdfweb.org/topic/Autodiscovery):
<link rel="meta" type="application/rdf+xml" href="/wiki?action=profile">

Hybrid:
<link rel="wiki.profile" type="application/rdf+xml"
href="/wiki?action=profile">

Hybrid, n3 version:
<link rel="wiki.profile" type="text/rdf+n3"
href="/wiki?action=profile&format=n3">

Also, the possibility of having a "standard location" like robots.txt
(http://www.robotstxt.org/) was mentioned, but was thought to be too
inflexible.

Out of all of these, I very much prefer the second, FOAF-style option,
because the profile is very much an example of metadata, and I'm not
too sure about how the "x.y" syntax works.

On the other hand, reading through the W3C specs, it is apparently
legal to have any QName (XML qualified name - see
http://www.w3.org/TR/xmlschema-2/#QName) as the value of a "link rel",
and a XML prefix can be used as long as it's been defined in an xmlns
attribute (http://www.w3.org/TR/xhtml2/mod-metaAttributes.html#adef_metaAttributes_rel).

So I guess it would be possible to do
<link rel="rdfs:isDefinedBy"  type="application/rdf+xml"
href="/wiki?action=profile#Wiki">

...but that seems a little over the top. <link rel=meta> is a
well-known style and shouldn't cause any problems.

Cheers,

Earle.

 --
Earle Martin
            http://downlode.org/
http://purl.org/net/earlemartin/