Rick Jelliffe on XML Schema

From the TAG list:

XML Schemas is like using a Swiss Army knife to cook with. Most Asian kitchens get by with a handful of simple tools: chopsticks, hatchet, a good knife, perhaps even a spoon. But the logic of  the XSD WG is “Oh, the French need to make quenelles, we must have a quenelling spoon as a grave matter of Internationalization because it is not our business to judge what people need… as long it is more stuff.”    So XSD 1.1 welds another Swiss Army knife onto the existing one, so that no kitchen should suffer without a quenelling spoon.

See also earlier comments on the Schema Experience Workshop from W3C.

So tool-makers blame users for generating non-standard schemas, and users blame the spec for being to difficult to know whether their schemas are standard or not, and spec makers blame tool makers for not implementing the spec properly. Who will free us from this cycle of sin and death?

[...] The only way that XML Schemas can be refactored is with a different core XML Schemas working group. My current expectation is that a lot of nothing will happen until XQuery/XSLT2 becomes seen as a more central technology than XML Schemas; the goal will then be how to support XQuery most minimally.

XSD doesn’t trouble me as much as it troubles Rick, but I have long sympathised with the approach he advocates with Schematron. The RDF equivalent of this is the approach Libby and I called “Schemarama”, expressing constraints against RDF instance data using queries. See original 2001 demo using SquishQL, and a later reworking by Alistair Miles using SPARQL (currently offline?). Recent work from the OWL experts at Clark & Parsia (blog post; another blog post) is heading in the same direction. I wonder whether Rick’s observation about XML applies to RDF too, and that at some point, SPARQL querying facilities will be so ubiquitous in RDF tools that it becomes second nature to apply it to data checking tasks too…?

Update: see also SpinRDF from Holger & co. at Top Quadrant

Site recovery

Busy sysadmin week. The main FOAF site is back, now hosted on Amazon EC2. Thanks to Stephane Corlosquet for all the time he spent fixing up the Drupal installation, after the recent server compromise. I’ve also moved over danbri.org (well, DNS is propagating), and migrated my blog into a completely fresh WordPress installation. The FOAF namespace site and Subversion server are safe, and not yet migrated to new hosting. Various documents from danbri.org are still offline while I scrub all the HTML, .js, .php etc for mischief. The old rdfweb.org site is also offline. I’d rather move slowly and carefully than mess up this process. This is a test post from the new WordPress to see if it works. Note that I’ve stripped all plugins and addons and will be much more conservative with trying extensions in the future. In particular, OpenID-based commenting isn’t working right now, but it’s on the todo list. One of the most disconcerting things about being hacked is when the site is also your OpenID. I’m wondering how to better partition things in the future; perhaps using id.danbri.org might give some more options?