XML Validation using DTD:

 

 

Hi ,

I am new to XML Parsing. I was supposed to Parse XML Doc , I did that using libxml DOM parser. But now i need to do it's validation also using DTD , My queries are:

1). According to me DTD using which validation is to be specified in XML file itself. Is it possible , DTD file need not be specified in XML File and still be used for validation purpose.?

 

Example:

<?xml version=&quot;1.0&quot;?>

<!DOCTYPE Sample SYSTEM "d.dtd">

 

 

2). I know of API xmlCtxtReadFile to get a ctxt for XML file and then check the validity of

ctxt->valid to know if File has passed validation or not.

Consider this :
static void
exampleFunc(const char *filename) {
   xmlParserCtxtPtr ctxt; /* the parser context */
 ;  xmlDocPtr doc; /* the resulting document tree */
 ;  /* create a parser context */
 ;  ctxt = xmlNewParserCtxt();
   if (ctxt == NULL) {
       fprintf(stderr, "Failed to allocate parser context\n&quot;);
&nbsp;      return;
 ;  }
   /* parse the file, activating the DTD validation option */
 ;  doc = xmlCtxtReadFile(ctxt, filename, NULL, XML_PARSE_DTDVALID);
   /* check if parsing suceeded */
 ;  if (doc == NULL) {
       fprintf(stderr, "Failed to parse %s\n", filename);
   } else {
       /* check if validation suceeded */
 ;      if (ctxt->valid == 0)
 ;          fprintf(stderr, "Failed to validate %s\n", filename);
       /* free up the resulting document */
 ;      xmlFreeDoc(doc);
   }
   /* free up the parser context */
 ;  xmlFreeParserCtxt(ctxt);
}

But this would not tell me which line/element failed validation? Any other way using libxml DOM.A way where I can do element by element validation.
I hope there are APIs to do that. Pls help me with some code snippet or Documentation.

Thx in Advance,
Rachita