postgres/contrib/xml2/xslt_proc.c

185 lines
3.5 KiB
C

/* XSLT processing functions (requiring libxslt) */
/* John Gray, for Torchbox 2003-04-01 */
#include "postgres.h"
#include "fmgr.h"
#include "executor/spi.h"
#include "funcapi.h"
#include "miscadmin.h"
/* libxml includes */
#include <libxml/xpath.h>
#include <libxml/tree.h>
#include <libxml/xmlmemory.h>
/* libxslt includes */
#include <libxslt/xslt.h>
#include <libxslt/xsltInternals.h>
#include <libxslt/transform.h>
#include <libxslt/xsltutils.h>
/* declarations to come from xpath.c */
extern void elog_error(int level, char *explain, int force);
extern void pgxml_parser_init();
extern xmlChar *pgxml_texttoxmlchar(text *textstring);
#define GET_STR(textp) DatumGetCString(DirectFunctionCall1(textout, PointerGetDatum(textp)))
/* local defs */
static void parse_params(const char **params, text *paramstr);
Datum xslt_process(PG_FUNCTION_ARGS);
#define MAXPARAMS 20
PG_FUNCTION_INFO_V1(xslt_process);
Datum xslt_process(PG_FUNCTION_ARGS) {
const char *params[MAXPARAMS + 1]; /* +1 for the terminator */
xsltStylesheetPtr stylesheet = NULL;
xmlDocPtr doctree;
xmlDocPtr restree;
xmlDocPtr ssdoc = NULL;
xmlChar *resstr;
int resstat;
int reslen;
text *doct = PG_GETARG_TEXT_P(0);
text *ssheet = PG_GETARG_TEXT_P(1);
text *paramstr;
text *tres;
if (fcinfo->nargs == 3)
{
paramstr = PG_GETARG_TEXT_P(2);
parse_params(params,paramstr);
}
else /* No parameters */
{
params[0] = NULL;
}
/* Setup parser */
pgxml_parser_init();
/* Check to see if document is a file or a literal */
if (VARDATA(doct)[0] == '<')
{
doctree = xmlParseMemory((char *) VARDATA(doct), VARSIZE(doct)-VARHDRSZ);
}
else
{
doctree = xmlParseFile(GET_STR(doct));
}
if (doctree == NULL)
{
xmlCleanupParser();
elog_error(ERROR,"Error parsing XML document",0);
PG_RETURN_NULL();
}
/* Same for stylesheet */
if (VARDATA(ssheet)[0] == '<')
{
ssdoc = xmlParseMemory((char *) VARDATA(ssheet),
VARSIZE(ssheet)-VARHDRSZ);
if (ssdoc == NULL)
{
xmlFreeDoc(doctree);
xmlCleanupParser();
elog_error(ERROR,"Error parsing stylesheet as XML document",0);
PG_RETURN_NULL();
}
stylesheet = xsltParseStylesheetDoc(ssdoc);
}
else
{
stylesheet = xsltParseStylesheetFile(GET_STR(ssheet));
}
if (stylesheet == NULL)
{
xmlFreeDoc(doctree);
xsltCleanupGlobals();
xmlCleanupParser();
elog_error(ERROR,"Failed to parse stylesheet",0);
PG_RETURN_NULL();
}
restree = xsltApplyStylesheet(stylesheet, doctree, params);
resstat = xsltSaveResultToString(&resstr, &reslen, restree, stylesheet);
xsltFreeStylesheet(stylesheet);
xmlFreeDoc(restree);
xmlFreeDoc(doctree);
xsltCleanupGlobals();
xmlCleanupParser();
if (resstat < 0) {
PG_RETURN_NULL();
}
tres = palloc(reslen + VARHDRSZ);
memcpy(VARDATA(tres),resstr,reslen);
VARATT_SIZEP(tres) = reslen + VARHDRSZ;
PG_RETURN_TEXT_P(tres);
}
void parse_params(const char **params, text *paramstr)
{
char *pos;
char *pstr;
int i;
char *nvsep="=";
char *itsep=",";
pstr = GET_STR(paramstr);
pos=pstr;
for (i=0; i < MAXPARAMS; i++)
{
params[i] = pos;
pos = strstr(pos,nvsep);
if (pos != NULL) {
*pos = '\0';
pos++;
} else {
params[i]=NULL;
break;
}
/* Value */
i++;
params[i]=pos;
pos = strstr(pos,itsep);
if (pos != NULL) {
*pos = '\0';
pos++;
} else {
break;
}
}
if (i < MAXPARAMS)
{
params[i+1]=NULL;
}
}