Re: [xml-dev] Reporting XML validation results in XML: is this approach sensible?

["Rick Jelliffe" <ricko@allette.com.au>]

From: "Henry S. Thompson" <ht@cogsci.ed.ac.uk>


> XSV [1] produces XML output, including error reports, which contain
> line and character numbers as attributes, e.g.
> 
>   <invalid char="5" code="cvc-elt.4.1.1" line="6"
>     resource="file:///. . ./triv.xml">element {None}e2 with simple
>                                       type not allowed attributes</invalid>
> 
> A stylesheet is provided which displays this in the traditional
> lineno:charno format.

Thanks for that, Henry.

I wonder if the first step towards also providing XPaths in error reports might
actually be to reform SAX to allow XPaths in locators, because some systems
(especially streaming systems) piggyback validation on top of SAX.  

I wonder if any implementers of validators would care to comment on what the
best way forward to allow XPath locators as a field/attribute might be, with the
intent of allowing plug-in validators that work as well as the lineno:charno format.

Cheers
Rick Jelliffe

* P.S., it seems that ISO DSDL might be favouring an XPath-based
approach for error messages, in that the particular limited form
of XML-syntax PSVIs that ISO DSDL would support would
have all augmentations/annotations/outcomes in a separate branch of 
XPaths to the original document, thus preserving the information-set 
of the original document intact, and keeping to the XML-in, XML-out
(XIXO) model. 

So perhaps ISO DSDL would be interested in a standardized
error-reporting format: certainly I am sure the Working Group would be
interested in implementation experience of systems that use
XPaths to link validation messages to the original source.  (For people
interested in this area, another place to look is the XLinkit technology.)

<outcome>
    <source>
        ... 
    </source>
    <errors>
        <error xlink:type="simple" xlink:href="#...">An error there</error>
        ...
    </errors>
</outcome>