[Om] Redirects: ocd now default; need another one [Re: Going real with the OpenMath CD Linked Data]

[Christoph LANGE]

Hi Paul,

On 27/07/2011 12:17, Paul Libbrecht wrote:
> Le 27 juil. 2011 à 11:44, Christoph LANGE a écrit :
>> BTW, contrary to the original .htaccess file that I sent you, I think
>> it would make sense to redirect requests to "cdname" without an Accept
>> header to the *.ocd files instead of *.xhtml.  That mainly addresses
>> users of command-line clients such as wget, and it would help to make
>> them aware of the original implementation of the CDs in the OCD
>> format.
>
> ok for me. Can you do it?

Done.

> that most validators follow 303 is clear.
> My problem with 303 is with browsers: they contain a history and that history's results (the target of the redirects) is what is exchanged with other people (copy and pasting URLs). This practice suffers from redirects because it lets the URL that is exchanged witness the representational nature (used to be .xml now is .xhtml) while it should not.
> …
> I am not disputing that 303 should redirect.
> I am disputing that we should use 303 instead of just serving.
> My point is that browsers should not receive redirects.
> I am fine with other tools to receive redirects.

I get your point. If discussed on public-lod at w3.org it might cause a
flamewar, but I'd say that _we_ do whatever serves _our_ purposes
best. So we might try to disable the 303 redirect when HTML is
requested and see what Vapour says. Any reasonable linked data client
should explicitly request application/rdf+xml, in the same way as any
reasonable browser should explicitly request text/html or
application/xhtml+xml. There is the theoretical option that more and
more linked data clients try application/xhtml+xml (in expectation of
XHTML+RDFa), but

1. I think that would rather only be the second option, if
application/rdf+xml is not available, and

2. we do not currently have RDFa annotations inside our XHTML files.
(But with the RDFa utilities of the Krextor library it wouldn't be too
hard to add that functionality to cd.xsl.)

>>> Robin Berjon had a particularly nice post here:
>>>     http://berjon.com/blog/2009/12/xmlbp-non-http-namespaces.html
>>> where he says... don't name the technology of your namespace document! Another day it's going to be another technology... I understand this as the fact that we should share URLs without the nitty gritty details that made us use .xml one day and .xhtml another day... just use one name and do the right thing (of today and in the future).
>>
>> I completely agree with that, and I think that with the improved
>> redirects we achieved exactly that.
>
> Except if people exchange the URL arith1.xhtml...

Got the point :-)

BTW, I'd need another redirect. I think I could do any necessary work
myself, but let me first explain; maybe you can give it a sanity check
before I start.

The OpenMath CD ontology, i.e. the RDF vocabulary that implements the
"abstract CD" specification, and which is heavily used in my RDF
files, has the namespace http://www.openmath.org/ontology#. These URIs
should also be served in a linked data way. (Note that the URI can
still be changed, as we have not yet publicly announced our data. –
I'd just like to keep this namespace separate from the CD namespace.)

The redirect would be very easy, as we currently only have this
ontology in RDF/XML (no content negotiation required), and as the
linked data best practices don't require a 303 redirect for hash URIs.
For my OMDoc ontology (see e.g. http://omdoc.org/ontology#Theory) the
redirect on omdoc.org is as simple as

RewriteRule ^/ontology$ /ontology/omdoc.owl [L]

I'd just need to make build.xml copy the
http://svn.openmath.org/OpenMath/OpenMath2++/owl/openmath.owl file to
/ontology.  For keeping the "www" directory self-contained, it might
also make sense to relocate the OpenMath2++/owl directory somewhere
into the "www" directory; how about "www/owl" or "www/ontology"?

Cheers,

Christoph

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