Re: [xml] XSchema and libxml

[Kasimier Buchcik <kbuchcik 4commerce de>]

Hi,

Daniel Veillard wrote:
> On Wed, Mar 09, 2005 at 05:16:46PM +0100, Christian HAESSIG wrote:
>
> > Hi people,
> >
> > I have a question about the XSchema integration in the library.
> > Is it possible to get and validate a xml file having a reference to its
> > schema in it ?
>
>
>   I think it's possible, you need to create the shemas context with a
> NULL URL, Kasimier should know more precisely.
>
>
> > Subsidiary question : does anyone have a little code/example for doing this
> > ?
>
>
>   if there is such an example I would add it to the example section
>
> Daniel

I attached an example.

Regards,

Kasimier

#include <stdio.h>
#include <libxml/parser.h>
#include <libxml/tree.h>
#include <libxml/xmlschemas.h>

#ifdef LIBXML_SCHEMAS_ENABLED

/**
 * validateViaXsi:
 * @filename: a filename or an URL
 *
 * Parse the instance document and validate it using the schemata
 * specified by xsi information.
 */
void 
validateViaXsi(const char *filename) {
    int res;    
    xmlDocPtr doc; /* the instance document */   
    xmlSchemaValidCtxtPtr validationCtxt; /* the XSD validation context */

    /* Read the instance document. */
    doc = xmlReadFile(filename, NULL, 0);
    if (doc == NULL) {
        fprintf(stderr, "Failed to parse the document '%s'.\n", filename);
        return;
    }

    /* A validation context created with NULL as the
     * @schema argument will validate the instance against the schemata
     * indicated by xsi:schemaLocation and xsi:noNamespaceSchemaLocation.
     */
    validationCtxt = xmlSchemaNewValidCtxt(NULL);
    if (validationCtxt == NULL) {
        fprintf(stderr, "Failed to create the validation context.\n");
        xmlFreeDoc(doc);
        return;
    }

    /* Validate the instance. */
    res = xmlSchemaValidateDoc(validationCtxt, doc);
    if (res == -1)
        fprintf(stderr, "Internal error during validation.\n");
    else if (res == 0)
        fprintf(stdout, "The document '%s' is valid.\n", filename);
    else
        fprintf(stderr, "The document '%s' is not valid.\n", filename);
    
    xmlSchemaFreeValidCtxt(validationCtxt);
    xmlFreeDoc(doc);

    return;     
}

int main(int argc, char **argv) {
    if (argc != 2)
        return(1);
    
    /*
     * this initialize the library and check potential ABI mismatches
     * between the version it was compiled for and the actual shared
     * library used.
     */
    LIBXML_TEST_VERSION
        
    validateViaXsi(argv[1]);
    
    /*
     * Cleanup function for the XML library.
     */
    xmlCleanupParser();
    /*
    * this is to debug memory for regression tests
    */
    xmlMemoryDump();
    return(0);
}
#else
int main(void) {
    fprintf(stderr, "XML Schema support not compiled in\n");
    exit(1);
}
#endif