[Om] Lots of our CDs (mostly the experimental ones) don't have a CDBase

[Christoph LANGE]

Hi David,

07/22/2011 09:06 PM David Carlisle:
>> I got the information that the CDBase is mandatory from the standard
>> section 4.2 "abstract CDs":
>
> ah yes.
>
>>
>> That clearly does not suggest that the CDBase is optional
>
> agreed, seems when this part was added we didn't clearly keep it aligned
> with the (older) other bits. Hmm. Although one could read this as saying
> that the abstract CD model has a CDBase property but the reference
> concrete syntax doesn't make it explicit.

In principle yes, but that's not quite the style of sections 4.2 and 
4.3.  All of the other pieces of information that 4.2 mandates are 
explicit in 4.3.

> (But also doesn't say how th
> eproperty should be inferred s= other is a spec bug somewhere)
>
>> About the CDBase of a CD my opinion is that we should not make it
>> default to http://www.openmath.org/cd, as the requirements are
>> different from writing OMOBJs.
>
> agreed it shouldn't default to openmath,org, but at least in the case
> that there's a CDURL (as there is in arith3 for example) defaulting
> CDBase to the bit of CDURL up to the last / would seem to make sense
> (since that is the inverse of the default way of constructing a URI from
> the CDBase and CDName) The other possible way of defaulting it if not
> specified would be to take the base URI of the CDfile being read,
> but as noted above the standard ought to have said either that it should
> be explicit or how to default it.

I rather tend to take the opposite point of view, namely the linked data 
point of view.  CDs have URIs, and their construction is specified as 
CDBase + "/" + CDName.  That is, whenever you want to retrieve some CD, 
you would first try to treat that URI as a URL.  From that point of view 
I'd rather say that the CDURL, if it's not specified, should default to 
the CDBase.  Anyone who is not capable of setting up HTTP redirects 
and/or content negotiation on his server can still provide an explicit 
CDURL.  I think that point of view is most consistent with the abstract 
CD spec: The spec requires a CD to have a CDBase (and says that from 
that URI/URL the CD may or may not be retrievable), but it doesn't 
mention a "CD URL".

>
>> So I think I will (maybe rather tomorrow than today):
>>
>> * add CDBases to all CDs in www/cdfiles2/cd
>> * add a check for CDBase to the validation XSLT

BTW, which of them is the right one?

./www/cdfiles2/xsl/cdvalidate.xsl
./www/cdfiles2/xsl/omvalidate-old.xsl
./www/cdfiles2/xsl/omvalidate.xsl

>> … but in addition to that we'd also need to fix the RelaxNG (if you
>> agree with my above reasoning).
>
> The Relax is a normative part of the standard (section 4.3) so I don't
> think that can just be edited in place, we need to open a ticket and
> incorporate any changes (if we decide they are needed) next time (or in
> a separate errata document or whatever we decide the process is)

Assuming that we agree on the point of view that the CD base should be 
mandatory in the Relax NG, I have just filed a ticket.  And another one 
about the inconsistent specification of the default CDBase for symbols.

Cheers,

Christoph

-- 
Christoph Lange, Jacobs University Bremen
http://kwarc.info/clange, Skype duke4701

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