Re: FW: OWL guide note?

On Fri, 2003-08-22 at 18:42, Charles White wrote:
> All,
> A note from one our engineers.
> charles
>         -----Original Message-----
>         From: Rob Shearer 
>         Sent: 22 August 2003 07:46
>         To: Jack Berkowitz; Engineering; Paul Turner; Matthew Quinlan
>         Subject: RE: OWL guide note?
>         My main concern is not in what the file extension is, but that
>         in making the change from .owl to .rdf the authors of the OWL
>         Guide have tried to hedge their bets and try going without any
>         extension at all. The "imports" statements in the ontologies
>         now reference a URLs that do not include *any* extensions.
>         However, the Guide continues to reference the food and wine
>         files *with* an extension, now ".rdf".

That seems like the source of the problem.

I hope to investigate further.

>          So if we load "wine.rdf", it imports "food", which in turn
>         imports "wine", a completely *different* URL. They've added
>         xml:base attributes such that the new statements from "wine"
>         should be exact duplicates of everything in "wine.rdf", but
>         the fact that we're now dealing with three files instead of
>         two just seems silly.
>         Much worse, this "two URLs for the wine file" thing is a huge
>         pain to configure. Maybe the W3C server guys managed to set up
>         two URLs for the same file, and made sure that the MIME type
>         mapping for the file without an extension must be RDF (since
>         the server can no longer automatically infer it from the
>         extension), but are server admins going to want to go through
>         such shenanigans for every ontology they publish?

One doesn't need to configure every ontology, or even every
MIME type. We use apache, and it's just a one-line config
file change, I think, to have requests for file_foo
serviced with the contents of file_foo.ext .

Details to follow...

>          And if you want to load an ontology not from a web server but
>         from a local file this sequence gets even worse, particular on
>         filesystems which don't allow symbolic links (which,
>         incidentally, are exactly those file systems on which
>         extensions are most important). How will Cerebra be able to
>         load the food and wine ontologies from local files on a
>         Windows machine?

If you're changing the address from
to file://... you can change the extension while you're at it.

But the smart thing to do is to build caching mechanisms into
your product so that it can map http://... names to local

Hmm... I ought to write this up as a best practice note/FAQ
in the ESW wiki... .

>         Getting these ".rdf" extensions back into the "imports" lines
>         is probably by far the easiest solution.

While that might be the locally easiest solution,
the point of doing work in W3C is to optimize globally.

Dan Connolly, W3C

Received on Thursday, 28 August 2003 13:25:13 UTC