[xml] Receiving RELAX NG validity error callbacks

[Todd Ditchendorf <todd ditchnet org>]

Can anyone help me with registering RELAX NG validity error callback  
functions?

I'm using the C RELAX NG API with xmlTextReader. I'm trying to  
register error callback functions for validity errors encoundtered in  
my *instance* document. I seem to be able to register handlers for  
all types of errors when parsing my RNG schema, and also well- 
formedness errors in my instance document. I can't seem to register  
error callbacks for *validity* errors in my instance doc as mandated  
by my RNG schema.

What's weird is that I do see these errors being reported to the  
console! These are the errors I want to receive in my C callbacks,  
but I can't find any way to register for them. Can anyone help? I've  
tried scouring xmllint.c for examples, but I just don't see where  
this happens. Other than that, I can't find any examples online.

Here's what I'm doing:



	char *docfurl = ".../golf.xml";
	char *schemafurl = ".../golf.rng";
	
	// RELAX NG Parser Context
	xmlRelaxNGParserCtxtPtr ctxt = xmlRelaxNGNewParserCtxt(schemafurl);
	xmlRelaxNGSetParserErrors(ctxt,
							  (xmlRelaxNGValidityErrorFunc)rngErr,
							  (xmlRelaxNGValidityWarningFunc)rngWarn,
							  NULL);
	
	// Parse schema
	xmlRelaxNGPtr schema = xmlRelaxNGParse(ctxt);
	
	// create reader
	xmlTextReaderPtr reader = xmlNewTextReaderFilename(docfurl);
	
	// associtate schema with reader
	xmlTextReaderRelaxNGSetSchema(reader, schema);
		
	// register some callbacks (apparently not the right ones)
	// never seems to be called
	xmlTextReaderSetErrorHandler(reader, (xmlTextReaderErrorFunc) 
readerErr, NULL);
	// handles well-formedness errors in instance document
	xmlTextReaderSetStructuredErrorHandler(reader,  
(xmlStructuredErrorFunc)structErr, NULL);
	
	while (xmlTextReaderRead(reader))
		;

	NSLog(@"done. isValid: %i", xmlTextReaderIsValid(reader));



The callbacks you see registered here are usually called for  
different things, but none for validity errors in the instance doc  
caused by non-adherence to my RNG.

The reader *does* correctly report whether it was valid or not at the  
end, which is good... but I want to receive the individual validity  
errors too.

Can anyone help?



Todd Ditchendorf

Scandalous Software - Cocoa Developer Tools
http://scan.dalo.us