Re: [xml] XML_CATALOG_DEBUG enhancement suggestion and yet another question

[Daniel Veillard <veillard redhat com>]

On Tue, Feb 21, 2006 at 05:56:27PM -0800, Rick Jones wrote:
> while I've been blundering through bootstrapping /etc/xml/catalog,  I've 
> come across something that may be a useful enhancement.  If one sets 
> XML_CATALOG_DEBUG, the output looks rather like:
>
> # xmllint --dtdattr --valid test_config.xml
> Resolve: sysID http://www.netperf.org/netperf_docs.dtd/1.0
> 1 Parsing catalog file:///etc/xml/catalog
> file:///etc/xml/catalog added to file hash
> Found system match http://www.netperf.org/netperf_docs.dtd/1.0
>
> It might be nice if the debug output stated what it was going to use based 
> on that match.

  okay, I take patch, this is debug output so I'm fine extending it !

> Also, while I was trying to decipher the OASIS stuff on XML catalogs I came 
> away with the impression that if a match target (?) failed to  load it 
> would keep trying to match until it found a target that would load or hit 
> the end of the catalog.  however, xmllint didn't seem to do that for this 
> catalog:

   Depends, if you hit a delegate, you don't backtrack, triple check the
7 steps described in the spec I'm fairly sure I followed then very precisely.

> # cat /etc/xml/catalog
> <?xml version="1.0"?>
> <!DOCTYPE catalog PUBLIC "-//OASIS//DTD Entity Resolution XML Catalog 
> V1.0//EN" 
> "http://www.oasis-open.org/committees/entity/release/1.0/catalog.dtd";>
> <catalog xmlns="urn:oasis:names:tc:entity:xmlns:xml:catalog">
>   <system systemId="http://www.netperf.org/netperf_docs.dtd/1.0"; 
> uri="file:///usr/local/share/netperf/nonesuch.dtd"/>
>   <system systemId="http://www.netperf.org/netperf_docs.dtd/1.0"; 
> uri="file:///usr/local/share/netperf/netperf_docs.dtd"/>
> </catalog>

  Not a very good construction usually you should use Delegates to 
point to a specialized catalog (usually stored in /usr/share/sgml IIRC)
to avoid filling up /etc/catalog with too specific entries, see how
docbook-dtds package on Fedora/Red Hat set up its catalogs.

> # xmllint --dtdattr --valid test_config.xml
> Resolve: sysID http://www.netperf.org/netperf_docs.dtd/1.0
> 1 Parsing catalog file:///etc/xml/catalog
> file:///etc/xml/catalog added to file hash
> Found system match http://www.netperf.org/netperf_docs.dtd/1.0
> Resolve URI file:///usr/local/share/netperf/nonesuch.dtd
> test_config.xml:2: I/O error : failed to load external entity 

  the match is exact, there is only one return value possible, so it fails
that's normal based on my understanding of the Catalog spec.

Daniel

-- 
Daniel Veillard      | Red Hat http://redhat.com/
veillard redhat com  | libxml GNOME XML XSLT toolkit  http://xmlsoft.org/
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