LCD_DocumentImpl.cc

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// $Id: LCD_DocumentImpl.cc,v 1.11 2004/02/02 22:12:48 uid561 Exp $
//
// LCD_Document.cxx
//
// Implementation file for the LCD classes supporting DOM:
//
//  LCD_DocumentImpl         implementation of above
//  LCD_DocManager           keeps track of all active LCD_Document's
//
// Other relevant classes have implementation, if any, in header file:
//  LCD_Document             largely virtual class describing interface
//  LCD_DocListener          entirely virtual
//
// Classes to handle the set of all XML documents known to a program
// (i.e., for which there are DOMs)

// There is a class LCD_DocumentImpl (should perhaps be an implementation of an
// interface) which acts as a small database describing a DOM.  There
// will be one instance per DOM.

// LCD_DocumentImpl has an enhanced set of query functions as compared to
// DOM_Document.  (Maybe I should change the name to LCD_Document.
// And maybe it should inherit from DOM_Document, except that,
// according to the DOM parser's documentation, the DOM_* classes
// cannot be subclassed.)

// There is another class (LCD_DocManager) which keeps track of all
// LCD_DocumentImpls.  There will be only one instance per program.

// The class LCD_DocListener just defines an interface for signing up
// to be notified of changes to a document.

#include "xercesc/util/PlatformUtils.hpp"
#include <algorithm>
//#include <strstream>
#include <list>
#include <iterator>
#include <iostream>

// see /afs/slac.stanford.edu/package/gcc/src/egcs-1.1.2/libio/strstream.h
#include "xercesc/dom/deprecated/DOM_Document.hpp"
#include "xercesc/dom/deprecated/DOM_Element.hpp"
#include "xercesc/dom/deprecated/DOMString.hpp"
#include "xercesc/dom/deprecated/DOMParser.hpp"
XERCES_CPP_NAMESPACE_USE

#include "LCD_DocListener.hh"
#include "LCD_DocumentImpl.hh"
// #include "LCD_DocManager.h"
#include "LCD_DocumentUtil.hh"
#include "LCD_DocErrorReporter.hh"

//#include <util/StdOut.hpp>

// XMLStdErr lcdErrStrm;
// using namespace std;

/*
 * Comment
 */
LCD_DocumentImpl::LCD_DocumentImpl(std::string XMLfilespec) {
  // This method should only be invoked by the  LCD_DocManager
  DOM_Element elt;

  errReporter = new LCD_DocErrorReporter();

  parser = new DOMParser();
  parser->setErrorHandler(errReporter);

  listeners = new std::list<LCD_DocListener*>;
  filespec = XMLfilespec;
}

// maybe  throw exception?

/*
 * Comment
 */
void LCD_DocumentImpl::parse() {

  // static const DOMString& descripString = DOMString("descrip");
  const DOMString& descripString = DOMString("descrip");
  DOM_Element elt;

  parser->parse(filespec.c_str());
  myDoc = parser->getDocument();

  //  firstRead = getCurrentTime();     to be defined
  firstRead = 0;

  elt = myDoc.getDocumentElement();

  // dtd doctype name must match tag name of root element of doc
  docTypeName = elt.getTagName();

  descrip = elt.getAttribute(descripString);

}

// Wend our way through the DOM, looking for element with id attribute
// whose value matches supplied id.  If elementName != "*" then only
// check elements of supplied name

/*
 * Comment
 */
DOM_Element LCD_DocumentImpl::getElement(DOMString id,
                                         DOMString elementName) const {
  DOM_Element  docElt = myDoc.getDocumentElement();
  DOMString idVal;
  DOMString idString = DOMString("id");

  if ((elementName.equals(DOMString("*"))) ||
      (elementName.equals(docElt.getTagName()) ) ) {
    idVal = docElt.getAttribute(idString);
    if (idVal.equals(id)) return docElt;
  }

  DOM_NodeList eltList = docElt.getElementsByTagName(elementName);
  int          len = eltList.getLength();
  DOM_Node     node;

  for (int i = 0; i < len; i++) {

    node =  (eltList.item(i));
    DOM_Element elt = (DOM_Element &) node;

    // Don't use the  following because it generates the compiler message
    //     warning: conversion to non-const `DOM_Element &' from
    //     rvalue `DOM_Node'
    // DOM_Element elt = (DOM_Element &) (eltList.item(i));

    idVal = elt.getAttribute(idString);

    if (idVal.equals(id)) return  elt;
  }

  return DOM_Element();
}

/*
 * Comment
 */
void LCD_DocumentImpl::registerListener(LCD_DocListener* ls) {
  listeners->push_front(ls);
}

/*
 * Comment
 */
int LCD_DocumentImpl::deleteListener(LCD_DocListener* ls) {

  std::list<LCD_DocListener*>::iterator
    which = std::find(listeners->begin(), listeners->end(), ls);
  if (which != listeners->end()) {

    // delete it from list
    listeners->erase(which);
  }
  else {
    return 1;  // not found
  }
  return 0;
}

// TO DO!!!

/*
 * Comment
 */
void LCD_DocumentImpl::notifyListeners() {
  // fetch listeners; invoke handler for each
  return;
}
//  end LCD_DocumentImpl stuff

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