[xml] accessing Parser-Ctxt in SAX based schema validation

[Holger Kaelberer <hkaelber math uni-bielefeld de>]

Hi,

I've got problems using SAX based validation against a xml schema.

I followed the procedure shown in xmllint.c which works fine.

The user-data passed to the sax-handlers must contain the parser-context 
(for accessing line-numbers). Without validation I did something like this:

/---
xmlParserCtxtPtr ctxt;
struct XMLparserState *state;
...
ctxt->sax = &parser_handler;
state->ctxt = ctxt;
ctxt->userData = state;
...
xmlParseDocument(ctxt);
---/

Is there an equiv. when using xmlSchemaValidateStream or any other way 
to access the parser ctxt of the parsed file?:

/---
...
state->ctxt = ...;
...
ret = xmlSchemaValidateStream(vctxt, buf, XML_CHAR_ENCODING_NONE,
   (xmlSAXHandlerPtr) parser_handler, state);
---/


Can someone help me with that?


One more thing concerning the SAX-Version: I was not able to do a 
validation with a SAX1-handler. 
According to xmlschemas.c xmlSchemaValidateStream presupposes a SAX2-handler: 


/---
/**
* xmlSchemaValidateStream:
* @ctxt:  a schema validation context
* @input:  the input to use for reading the data
* @enc:  an optional encoding information
* @sax:  a SAX handler for the resulting events
* @user_data:  the context to provide to the SAX handler.
*
* Validate an input based on a flow of SAX event from the parser
* and forward the events to the @sax handler with the provided @user_data
* the user provided @sax handler must be a SAX2 one.
*
* Returns 0 if the document is schemas valid, a positive error code
*     number otherwise and -1 in case of internal or API error.
*/
int
xmlSchemaValidateStream(xmlSchemaValidCtxtPtr ctxt,
                       xmlParserInputBufferPtr input, xmlCharEncoding enc,
                       xmlSAXHandlerPtr sax, void *user_data)
---/

But xmllint.c seems to work with a SAX1-handler too:

/----
   if (noout) {
       handler = emptySAXHandler;
#ifdef LIBXML_SAX1_ENABLED
   } else if (sax1) {
       handler = debugSAXHandler;
#endif
   } else {
       handler = debugSAX2Handler;
   }
...
---/

What's the state here?

Thanks in advance,
 Holger