TDOMParser.cxx

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// @(#)root/xmlparser:$Id$
// Author: Jose Lo   12/4/2005
 
/*************************************************************************
 * Copyright (C) 1995-2005, Rene Brun and Fons Rademakers.               *
 * All rights reserved.                                                  *
 *                                                                       *
 * For the licensing terms see $ROOTSYS/LICENSE.                         *
 * For the list of contributors see $ROOTSYS/README/CREDITS.             *
 *************************************************************************/
 
/**
\class TDomParser
\ingroup IO
 
DOM stands for the Document Object Model; this is an API for
accessing XML or HTML structured documents.
The Document Object Model is a platform and language-neutral
interface that will allow programs and scripts to dynamically
access and update the content, structure and style of documents.
 
The parser returns a tree built during the document analysis.
*/
 
#include "TDOMParser.h"
#include "TXMLDocument.h"
 
#include <libxml/tree.h>
#include <libxml/parserInternals.h>
 
 
ClassImp(TDOMParser);
 
////////////////////////////////////////////////////////////////////////////////
/// TDOMParser constructor.
 
TDOMParser::TDOMParser() : fTXMLDoc(0)
{
}
 
////////////////////////////////////////////////////////////////////////////////
/// TDOMParser destructor, it calls ReleaseUnderlying().
 
TDOMParser::~TDOMParser()
{
   ReleaseUnderlying();
}
 
////////////////////////////////////////////////////////////////////////////////
/// Release any existing document.
 
void TDOMParser::ReleaseUnderlying()
{
   if (fTXMLDoc) {
      delete fTXMLDoc;
      fTXMLDoc = 0;
   }
 
   SetParseCode(0);
 
   TXMLParser::ReleaseUnderlying();
}
 
////////////////////////////////////////////////////////////////////////////////
/// Parse the XML file where filename is the XML file name.
/// It will create a TXMLDocument if the file is parsed without
/// any error. It returns parse code error in case of parse error,
/// see TXMLParser.
 
Int_t TDOMParser::ParseFile(const char *filename)
{
   ReleaseUnderlying();
 
   fContext = xmlCreateFileParserCtxt(filename);
 
   if (!fContext) {
      SetParseCode(-2);
      return -2;
   }
 
   InitializeContext();
 
   if (!fContext->directory) {
      const char *dir = xmlParserGetDirectory(filename);
      fContext->directory = (char *)xmlStrdup((const xmlChar *)dir);
   }
 
   return ParseContext();
}
 
////////////////////////////////////////////////////////////////////////////////
/// It parses a buffer, much like ParseFile().
 
Int_t TDOMParser::ParseBuffer(const char *buffer, Int_t len)
{
   ReleaseUnderlying();
 
   fContext = xmlCreateMemoryParserCtxt(buffer, len);
 
   if (!fContext) {
      SetParseCode(-2);
      return -2;
   }
 
   InitializeContext();
 
   return ParseContext();
}
 
////////////////////////////////////////////////////////////////////////////////
/// Creates a XML document for the parser.
/// It returns 0 on success, and
///   - \b -1 if no XML document was created,
///   - \b -5 if the document is not well formated,
///   - \b -6 if document is not valid.
 
Int_t TDOMParser::ParseContext()
{
   xmlParseDocument(fContext);
 
   if (!fContext->myDoc) {
      SetParseCode(-1);
      return -1;
   }
 
   if (!fContext->wellFormed) {
      SetParseCode(-5);
      return -5;
   }
 
   if (!fContext->valid) {
      SetParseCode(-6);
      return -6;
   }
 
   fTXMLDoc = new TXMLDocument(fContext->myDoc);
 
   return 0;
}
 
////////////////////////////////////////////////////////////////////////////////
/// Returns the TXMLDocument.
 
TXMLDocument *TDOMParser::GetXMLDocument() const
{
   return fTXMLDoc;
}