gxXmlAbstractParser.h

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/*  Copyright (C) 2004  Guido Simone
 *
 *  This program is free software; you can redistribute it and/or modify
 *  it under the terms of the GNU General Public License as published by
 *  the Free Software Foundation; either version 2 of the License, or
 *  (at your option) any later version.
 *
 *  This program is distributed in the hope that it will be useful,
 *  but WITHOUT ANY WARRANTY; without even the implied warranty of
 *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 *  GNU General Public License for more details.

 *  You should have received a copy of the GNU General Public License
 *  along with this program; if not, write to the Free Software
 *  Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
 */

#ifndef GXLIB_GXXMLABSTRACTPARSER_H
#define GXLIB_GXXMLABSTRACTPARSER_H

#include "../../gx.h"
#include "gxXmlElement.h"
#include "gxXmlElementSpec.h"
#include <expat/expat.h>


class gxXmlAbstractParser
{
public:
   gxXmlAbstractParser( char * elemSpecs[] = NULL);
   virtual ~gxXmlAbstractParser();

   int parse(const std::string & s, int isFinal = true);
   int parse(const char *s, int len, int isFinal = true);

   void stop();

   void error( const char * errorMessage, int errorCode = PARSE_APPERROR );

   void clear();


   // Expat defines some XML_ERROR codes beginning at XML_ERROR_NONE.
   // Add our own error codes to handle the case where the XMl is valid
   // but it does not match the specs (invalid element name etc.).
   // An offset of 400 should be sufficient so there is no conflict
   // any time soon.  Also, the subclass may define its own error codes
   // so use an offset of 500 as the base for these error codes
   enum {
      PARSE_OK = XML_ERROR_NONE,
      PARSE_BADELEMENT = XML_ERROR_NONE + 400,
      PARSE_BADATTRIBUTE = XML_ERROR_NONE + 401,
      PARSE_CANTBEROOT = XML_ERROR_NONE + 402,
      PARSE_MUSTBEROOT = XML_ERROR_NONE + 403,
      PARSE_MISSINGATTRIBUTE = XML_ERROR_NONE + 404,
      PARSE_APPERROR = XML_ERROR_NONE + 500
   };
   int getLastError();
   std::string getLastErrorMessage();
   void setLastError( int error );
   void setLastErrorMessage( const char * message );

   void addSpec( const char * spec );
protected:
   typedef std::map<std::string, gxXmlElementSpec> element_specs_t;
   element_specs_t elementSpecs;

   virtual int verifyElement();

   // called when an element is complete
   virtual void onElement() = 0;

   gxXmlElement & getCurrentElement();
   bool hasParent();
   gxXmlElement & getParentElement();
   typedef std::list< gxXmlElement> context_t;
   context_t m_context;

private:
   int m_lastError;
   std::string m_lastErrorMessage;

   // additional info from element spec
   std::string m_lastErrorMessage2;

   XML_Parser m_parser;
   static void XMLCALL startElement(void *userData, const char *name, const char **atts);
   static void XMLCALL endElement(void *userData, const char *name);
   static void XMLCALL characterData (void *userData,  const XML_Char *s, int len);

   void buildErrorMessage();
   const char * getXmlErrorName( int error );
private:
   gxXmlAbstractParser( const gxXmlAbstractParser & rhs);
   gxXmlAbstractParser & operator=( const gxXmlAbstractParser & rhs);
};
#endif

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