Don’t call me DOM

1 September 2004

Dealing with dates in cwm

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cwm is the main Semantic Web toolkit I use to manipulate RDF; while it has some speed issues – really, it shouldn’t have them in the next release -, it allows to use N3 Rules which are tricky to write, but are so much more powerful than declarative programing that at least you feel good once you have written them.

A recurrent pattern I have encountered regards dealing with date differences, e.g. comparing the date of publication of a document with the current date; here is what I’m using (e.g. in detect-missing.n3):

7 July 2004

A Semantic Web protocol for updates to a knowledge base

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For quite some time now (from our Team-only archives, I find a reference back in September 2002) I have been thinking to deploy the following protocol to update RDF knowledge bases, that takes advantage of RDF mergeability and of the concept of filtering in cwm (the command line tool for Semantic Web operations developed by the SWAD Team at W3C).

The general idea is to allow one to HTTP POST a chunk of RDF to an RDF file on a Web server, and have the RDF chunk added to the file, but with the possibility of filtering who gets to add what type of data. Let’s get a little more in the details…

Picture of Dominique Hazael-MassieuxDominique Hazaël-Massieux ( is part of the World Wide Web Consortium (W3C) Staff; his interests cover a number of Web technologies, as well as the usage of open source software in a distributed work environment.