RE: [xml-dev] RE: Compelling use case for XML Catalogs?

["Tony Graham" <tgraham@mentea.net>]

On Mon, June 13, 2011 4:24 pm, Costello, Roger L. wrote:
> John Cowan responded to my post:
>
>> Does XML Catalog have the ability to express this:
>>>
>>>[snip various conditional things]
>>>
>>> No, of course not.  Catalogs can only express one thing: when you
>>> see this URI, use this other URI instead.  (And ditto for public
>>> identifiers.)
>
> The inability of XML Catalog to check for the presence of correct URLs
> seems like a significant limitation.

XML Catalogs are just data.  Throwing an error in the absence of a match,
forcing validation against a specified schema, and prohibiting network
access when validating are all things you would do in software.

See, e.g., the '--dtdvalid', '--relaxng', '--schema', '--schematron', and
'--nonet' options of 'xmllint' [1].  'xmllint' doesn't complain if the
document doesn't refer to a URI that's in a catalog, but you could modify
it to do so if you wanted, and you could do much the same as 'xmllint' in
any XML processor for which you had the source code (if it doesn't do it
already that is).

Regards,


Tony Graham                                   tgraham@mentea.net
Consultant                                 http://www.mentea.net
Mentea       13 Kelly's Bay Beach, Skerries, Co. Dublin, Ireland
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[1] http://www.xmlsoft.org/xmllint.html
    The help for the under-documented '--nonet' option is:

      refuse to fetch DTDs or entities over network