Re: [xslt] Functions for fetching file list

[crispin iinet net au]

On Tue, Jul 17, 2001 at 08:51:54AM +0000, Matt Sergeant wrote:
> On 17 Jul 2001 12:21:53 +0800, crispin@iinet.net.au wrote:
> > Hi,
> > 
> > I need during processing an XML document with an XSLT sheet to gather a list of all the files that were needed in the process. 
> > 
> > If you use xsltproc like this
> > 
> > xsltproc -v test.xsl welcome.xml
> > 
> > in the output you get the following lines
> > 
> > parsed 3 templates
> > Initializing keys on welcome.xml
> > Registering global variables
> > Registering global variables from test.xsl
> > Registering global variables from theme.xsl
> > 
> > Which are the three files used. xsltproc uses xsltSetGenericDebugFunc(stderr, NULL); to pipe that info to stderr. 
> > 
> > I would like however, to get this information more directly. What is the best way of doing this?
> 
> Create your own input callbacks, and get the information from there.

Input callbacks, eh?

I looked through the xslt and xml API documentation (terribly brief) and the only thing that matched was in libxml in xmlIO. A function xmlRegisterInputCallbacks.
So I tried the following code...

----------------------------------------------------
int MatchCallback(const char *filename)
{
	printf("matchCallback(%s)\n",filename);
	return 0;
}

void *OpenCallback(const char *filename)
{
	printf("openCallback(%s)\n",filename);
	return NULL;
}

int ReadCallback(void *context, char *buffer, int len)
{
	printf("readCallback(%d,%s,%d)\n",(int)context,buffer,len);
	return 1;
}

void CloseCallback(void *context)
{
	printf("closeCallback(%d)\n",(int)context);
}

void InstallCallbacks()
{
	xmlRegisterInputCallbacks(MatchCallback,OpenCallback,ReadCallback,CloseCallback);
}
----------------------------------------------------

Just to see what they would do. Then my processing code went...

----------------------------------------------------
	xsltStylesheetPtr ss = NULL;					/* will hold the stylesheet */
	xmlDocPtr doc, res;								/* will hold the xml and the result */
	xmlOutputBufferPtr outputxml=NULL;

	InstallCallbacks();					/* INSTALLS THE CALLBACKS HERE */

	/* generate html. Store in buffer. Store a list of contributed files in filelist */
	printf("1\n");
	outputxml=xmlAllocOutputBuffer(NULL);
	
	printf("2\n");
	xmlSubstituteEntitiesDefault(1);				/* perform entity substitution */
	xmlLoadExtDtdDefaultValue = 1;				/* load external entity subsets */
		
	printf("3\n");
	/* load files and generate output */
	ss = xsltParseStylesheetFile((const xmlChar *)xslfile);
	printf("4\n");
	doc = xmlParseFile(xmlfile);
	printf("5\n");

	res = xsltApplyStylesheet(ss, doc, NULL);
	
	printf("6\n");
	xsltSaveResultTo(outputxml, res, ss);
	
	printf("7\n");
	/* clean up */
	xsltFreeStylesheet(ss);
	xmlFreeDoc(res);
	xmlFreeDoc(doc);
	
	printf("8\n");
	
	/* now outputxml holds the resultant html */
	xmlOutputBufferClose(outputxml);
----------------------------------------------------

However it appears none of my callbacks were called. I got no output from them at all. So either...

1) xmlRegisterInputCallbacks is not the function I want

or

2) I'm calling xmlRegisterInputCallbacks incorrectly or implementing the callbacks incorrectly

Any help is appreciated. I need some more info on what API function calls are the ones I want. Either that or point me to some example code, or tute or docs.

Thanks everyone.

Crispin