/* Some useful utilities that work with the Xerces-C API. Allows you to 
* get the actual data out of Elements and Attributes. Uses DualString 
* class which can be down loaded from the O'Reilly tutorial:
* http://www.onlamp.com/pub/a/onlamp/2005/09/08/xerces_dom.html
* Code below is copyright Alisa Neeman Feb. 4, 2006 
* COPY LEFT and RIGHT:
* Commercial  use of this  program without express permission of 
* the University, is strictly encouraged. Copyright and Copyleft are covered
* by the following clause:
 *
* Woody's (Guthrie) license:																																		
* ``This  source code is Copyrighted in U.S., by the The University 
* and  by the Author,  for  an indefinite period, and anybody caught
* using  it  without  our  permission,  will be mighty good friends of 
* ourn, cause  we  don't give a darn. Hack it. Compile it. Debug it. Run it. 
* Yodel it. Enjoy it. We wrote it, that's all we wanted to do.'' bj
*/

 /* 
 * given a Document Element, and an attribute name, return the value
 * of the attribute if it is an integer
 */
int getAttrIntValueByName( DOMElement * el, const XMLCh * attrName ) {
  int id;
  DOMAttr * idVal =  el->getAttributeNode( attrName );	
  
  DualString valString( idVal->getValue() ); // no worries: string is copied
  id = atoi( valString.asCString() ); 
  // DualString valString destructor called on return
  return id;
}

/**
 * given a Document Element, and an attribute name, return the value
 * of the attribute if it is an double
 */
double getAttrDoubleValueByName( DOMElement * el, const XMLCh * attrName ) {
  double val ;
  DOMAttr * attVal =  el->getAttributeNode( attrName );	
  
  DualString valString( attVal->getValue() );  
  val = atof( valString.asCString() ); 
 
  return val;
}

/**
 * Given an document element, and the name of one of its
 * child elements, fetch the first child  so named and return 
 * the value, if the value is an integer.
 * <Element> integer </Element> 
 */
int getFirstChildIntValue( DOMElement * el, const XMLCh * childName ) {
  DOMNodeList * nl;  
  int val = -1;
  nl = el->getElementsByTagName( childName );

  if( nl != NULL  && nl->getLength() > 0 ) {

	DOMElement  * kinder = 
	  dynamic_cast<DOMElement *> ( nl->item(0));
	if ( kinder == NULL ) {
	  std::cerr << "Error trying to get node's " << 
XMLString::transcode(childName);
	  exit (-1);
	}
	
	//try getting child 
	//this should be a DOMCaharacterData node
	DOMCharacterData * chardata = 
	  dynamic_cast<DOMCharacterData *> ( kinder->getFirstChild() );
	DualString data( chardata->getData() );
	val = atoi( data.asCString() );
  }

  return val;
}

/**
 * Given an document element, and the name of one of its
 * child elements, fetch the first child  so named and return 
 * the value, if the value is a double. 
 *<Element> double </Element>
 */
double getFirstChildDoubleValue( DOMElement * el, const 
XMLCh * childName ) {
  DOMNodeList * nl;  
  double val = -1;
  nl = el->getElementsByTagName( childName );

  if( nl != NULL  && nl->getLength() > 0 ) {

	DOMElement  * kinder = dynamic_cast<DOMElement *> ( nl->item(0) );
	if ( kinder == NULL ) {
	  std::cerr << "Error trying to get node's " << 
XMLString::transcode( childName );
	  exit (-1);
	}
	
	//try getting child 
	//this should be a DOMCharacterData node
	DOMCharacterData * chardata = 
	  dynamic_cast<DOMCharacterData *> ( kinder->getFirstChild() );
	DualString data( chardata->getData() );
	val = atof( data.asCString() );
  }

  return val;
}