A C++ Implementation of DOM Core Code

#include "DOM.h"

#include <stdio.h>
#include <string.h>
#include <ctype.h>


boolean  DOMImplementation::hasFeature(String feature, String version)
{
  for (int i=0; i<strlen(feature); i++)
     feature[i] = toupper(feature[i]);
  if (  strcmp(feature, "XML")==0 && strcmp(version, "1.0")==0 )
        return true;
  else  return 0;
}


Node*  DOMImplementation::setCurrentNode(Node* newNode)
{
  Node* oldNode = getCurrentNode();
  currentNode = newNode;
  return oldNode;
}


boolean  DOMImplementation::docParse(String xmlFile, String dtdFile)
{
  if ( xmlParse(xmlFile) == NULL )
    {
      fprintf(stderr, "couldn't parse xml file: %s \n", xmlFile);
      return 0;
    }

  if ( dtdParse(dtdFile) == NULL )
    {
      fprintf(stderr, "couldn't parse dtd file: %s \n", dtdFile);
      return 0;
    }

  return 1;
}


//////////////////// xmlParse ////////////////////////////////

#include "callbacks.c"

DocumentFragment*  DOMImplementation::xmlParse(String fileName)
{
  Document* doc = getOwnerDoc();
  DocumentFragment* docTree = doc->createDocumentFragment();
  setCurrentNode(docTree);

  depth = 0;   // used for debugging expat, delete this later

  XML_Parser parser = XML_ParserCreate(NULL);
  XML_SetUserData(parser, this);

  // set event handlers
  installCallbacs(parser);

  // open file
  FILE* inf = fopen(fileName, "r");
  if (inf == NULL)
    {
      fprintf(stderr, "DOMImplementation::xmlParse: cannot open file %s for reading\n", fileName);
      return NULL;
    }

  // parse
  char buf[BUFSIZ];
  int done;
  do
    {
      size_t len = fread(buf, 1, sizeof(buf), inf);
      done = len < sizeof(buf);
      if (!XML_Parse(parser, buf, len, done))
        {
          fprintf(stderr, "%s at line %d\n",
                    XML_ErrorString(XML_GetErrorCode(parser)),
                    XML_GetCurrentLineNumber(parser));
          return NULL;     // not parsed correctly
        }
    } while (!done);

  XML_ParserFree(parser);

  Element* docRoot = doc->createElement("xml");
  doc->setDocumentElement(docRoot);
  docRoot->appendChild(docTree);

  return docTree;
}


///////////////// dtdParse ////////////////////////

#include "y.tab.c"

DocumentType*  DOMImplementation::dtdParse(String fileName)
{
  // redirect stdin to fileName
  if ( freopen(fileName, "r", stdin) == NULL )
    {
      fprintf(stderr, "DOMImplementation::dtdParse: cannot open file: %s for reading", fileName);
      return NULL;
    }

  // initialize global variables used by dtd parser
  xmlDoc  = getOwnerDoc();  // the owner of this DOMImplementation instance
  docType = xmlDoc->getDoctype();
  elems   = docType->getElements();
  attribs = docType->getAttributes();

  // now parse by calling "yyparse"
  // this builds the dtd structure
  try { yyparse(); }
  catch (DOMException& e)
      { cout << e << endl;  return NULL; }

  return docType;
}