Re: [xml] RelaxNG validation error reporting

[Daniel Veillard <veillard redhat com>]

On Mon, Nov 03, 2003 at 10:45:29AM +0100, Petr Pajas wrote:
> Hi Daniel, All,

  Hi,

> I have two questions conserning RelaxNG validation error reporting,
> but the same may also apply to DTD and XSD (I didn't check that).
>
> 1) I was quite surprised, that setting xmlRelaxNGSetValidErrors error
> handlers to fprintf versus setting it to my custom routine (which in
> turn only wraps vsprintf or similar), produce different error
> messages: with fprintf I get full information, including filename and
> line numbers, while with any other custom routine I only get the
> 'body' of the error message (no filename, line no.). My question is,
> is it intentional (seems so according the code in error.c), and is

  yes intentional, so there is only one callback per error which was
a highly requested change. This also mean I can't make a callback 
for the context, and then a callback for the error informations.
The application can then grab the informations from the context or
the structured error handler.

> there a way to get full error information *without* rewriting the
> existing application code to use the new structured error reporting

  That will be hard at this point. I had to revamp the error handling
code while maintaining minimal compatibility, and offer a more complete
API. The trade-off was to somewhat degrade the old processing, this was
the only way I could do this without getting into dangerous corner cases.

> (I'm doing some work on XML-LibXML perl binding and at this point, I
> just want to fix things, not rework, preserving compatibility with
> 2.5.x versions as long as possible; some rearranging may come later).

  understood, sorry about that but that part seriously changed, and there is
no easy workaround.

> 2) sometimes, libxml2 only reports, that the document didn't validate
> without giving any specific reason (just returns 1 from
> xmlRelaxNGSetValidErrors but doesn't raise any error via the error
> handlers). In these cases, xmllint only says 'fails to validate'.  I
> have no 'real-life' examples for this, but try for example
>
> xmllint --noout --relaxng tutorA.rng demo.xml
>
> (files from libxml2's test/relaxng/). I would expect something like
> "expecting element got TEI.2". Is it a bug? If not, are there some
> typical situations, for this to happen?

  Then it's a bug, please bugzilla it !

    thanks,

Daniel

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