xml.h

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/**********************************************************************
xml.h Declaration of XMLConversion,
declaration and definition of XMLBaseFormat and XMLMoleculeFormat
Copyright (C) 2005-2006 by Chris Morley

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 version 2 of the License.

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.
***********************************************************************/

#ifndef OB_XML_H
#define OB_XML_H

#include <typeinfo>

#include <openbabel/obconversion.h>
#include <openbabel/obmolecformat.h>
#include <openbabel/mol.h>

#include <libxml/xmlreader.h>
#include <libxml/xmlwriter.h>
#include <typeinfo>

namespace OpenBabel
{


  //forward declaration
  class XMLBaseFormat;

  //******************************************************
  class XMLConversion : public OBConversion
    {
    public:
      XMLConversion(OBConversion* pConv);

      ~XMLConversion();

      bool SetupReader();
      bool SetupWriter();

      bool ReadXML(XMLBaseFormat* pFormat, OBBase* pOb);

      int SkipXML(const char* ctag);

      typedef std::map<std::string, XMLBaseFormat*> NsMapType;

      static NsMapType& Namespaces()
        {
          static NsMapType ns;
          return ns;

          //static NsMapType* nsm = NULL;
          //if (!nsm)
          //  nsm = new NsMapType;
          //return *nsm;
        };

      static void RegisterXMLFormat(XMLBaseFormat* pFormat,
                                    bool IsDefault=false, const char* uri=NULL);

      static XMLConversion* GetDerived(OBConversion* pConv, bool ForReading=true);

      bool IsLast()
        { return _pConv->IsLast(); }
      int GetOutputIndex()
        { return  _pConv->GetOutputIndex(); }


      xmlTextReaderPtr GetReader() const
        { return _reader;   };

      xmlTextWriterPtr GetWriter() const
        { return _writer;   };

      void OutputToStream()
        {
          xmlOutputBufferFlush(_buf);
        }

      static XMLBaseFormat* GetDefaultXMLClass() //TODO make dependent on object type
        { return _pDefault;};

      void LookForNamespace()
        { _LookingForNamespace = true; };

      static int ReadStream(void * context, char * buffer, int len);
      static int WriteStream(void * context, const char * buffer, int len);
      //static int CloseStream(void* context);

      std::string GetAttribute(const char* attrname);

      std::string GetContent();

      bool    GetContentInt(int& value);

      bool GetContentDouble(double& value);

    private:
      static XMLBaseFormat* _pDefault;
      OBConversion* _pConv;
      std::streampos  _requestedpos, _lastpos;
      xmlTextReaderPtr _reader;
      xmlTextWriterPtr _writer;
      xmlOutputBufferPtr _buf;
      //    xmlBufferPtr _buf;
      bool _LookingForNamespace;
    public:
      bool _SkipNextRead;
    };

  //*************************************************
  class XMLBaseFormat : public OBFormat
    {
    protected:
      XMLConversion* _pxmlConv;

      //formating for output
      std::string _prefix;
      int baseindent, ind;
      std::string nsdecl;
      int _embedlevel;

    public:
      ~XMLBaseFormat(){}
      virtual const char* NamespaceURI()const=0;
      virtual bool DoElement(const std::string& ElName){return false;};
      virtual bool EndElement(const std::string& ElName){return false;};
      virtual const char* EndTag(){return ">";};

    protected:
      xmlTextReaderPtr reader() const
        {
          return _pxmlConv->GetReader();
        }

      xmlTextWriterPtr writer() const
        {
          return _pxmlConv->GetWriter();
        }

      void OutputToStream()
        {
          _pxmlConv->OutputToStream();
        }

      virtual int SkipObjects(int n, OBConversion* pConv)
        {
          //don't implement on base class
          if(*EndTag()=='>')
            return 0;

          //Set up XMLConversion class with reader
          _pxmlConv = XMLConversion::GetDerived(pConv,true);
          if(!_pxmlConv)
            return -1;

          //always find the end of at least 1 object
          if(n==0)++n;

          //Skip n objects, returning -1 if not successful
          int i;
          for(i=0; i<n; ++i)
            if(_pxmlConv->SkipXML(EndTag())!=1)
              return -1;

          return 1;
        }

    };

  //*************************************************
  class XMLMoleculeFormat : public XMLBaseFormat
    {
    protected:
      OBMol* _pmol;

    public:
      ~XMLMoleculeFormat(){}
      virtual bool ReadChemObject(OBConversion* pConv)
        {
          return OBMoleculeFormat::ReadChemObjectImpl(pConv, this);
        };

      virtual bool WriteChemObject(OBConversion* pConv)
        {
          return OBMoleculeFormat::WriteChemObjectImpl(pConv, this);
        };

      virtual bool ReadMolecule(OBBase* pOb, OBConversion* pConv)
        {
          _pmol = dynamic_cast<OBMol*>(pOb);
          if(!_pmol)
            return false;
          _pxmlConv = XMLConversion::GetDerived(pConv,true);
          if(!_pxmlConv)
            return false;
          _embedlevel = -1;
          return _pxmlConv->ReadXML(this,pOb);
        };

      const std::type_info& GetType()
        {
          return typeid(OBMol*);
        };

    };


}//namespace


#endif