Re: DOCBOOK-APPS: RE: XML catalog resolution problems

[Daniel Veillard <veillard at redhat dot com>]

On Wed, Oct 30, 2002 at 01:58:30PM -0600, Paul Grosso wrote:
> >  The XML spec in 4.2.2 explicitely state that in production 75 
> >the System ID is an URI-Reference and link to RFC 2396.
> 
> RFC 2396 <ftp://ftp.ietf.org/rfc/rfc2396.txt> defines:
> 
>   URI-reference = [ absoluteURI | relativeURI ] [ "#" fragment ]
> 
> The XML spec says a system identifier cannot include a fragment identifier.
> 
> So the XML system identifier matches [ absoluteURI | relativeURI ]
> in RFC 2396 (for which there is no single name given in 2396)
> whereas the URIs matched by the uri catalog entry match the full
> URI-reference production above.

  The spec says it's an URI-Reference. It references the RFCs explaining
how to compute the final URI from those references. The fact that there
are restrictions from the full set admited as the URI-References input doesn't
mean that the mechanism should not be used. The only meaning is that one cannot 
try to point to a subsection of the target resource, period. It does not
mean that the URI-Reference to URI mechanism by composition to the base
must be voided or be made specific.

> >  The XInclude spec does the same for the href attribute.
> >  There is no XML Base, so both references uses the same base
> >and anybody with some common sense would expect the two references
> >to get to the same resource.
> 
> An XInclude href consists of a URI.  An XML doctype declaration's
> ExternalID consists of both a public identifier and a system identifier.
> They sound very different to me, and it makes perfect sense for two
> such different references to be able to resolve to different resources.

  When there is a public ID, then the public ID may point to something
else. In the case where there is twice the exact same system ID I don't
see any reasonnable justification to distinguish those. You're asking for
the same resource, why would you magically get different results ?
  Moreover when there are both System ID and Puyblic ID the XML Catalog
spec clearly separate the lookup processing by public and system ID.
As a result the work to be done on a system ID is exactly similar to the
one one need to take for another URI reference except the identifiers
in the catalog need to be magically different.

> I very much disagree with your "broken" assertion, Daniel.

  I ask of resource A, then A again, and get different results
without the actual resource having changed in the meantime. Yeah
I think this is broken, 

Daniel

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