/*
    * Copyright (c) 2008, The JUNG Authors
    *
    * All rights reserved.
    *
    * This software is open-source under the BSD license; see either
    * "license.txt" or
    * https://github.com/jrtom/jung/blob/master/LICENSE for a description.
    */
  
  package edu.uci.ics.jung.io.graphml.parser;
  
  import javax.xml.stream.XMLEventReader;
  import javax.xml.stream.events.Characters;
  import javax.xml.stream.events.EndElement;
  import javax.xml.stream.events.StartElement;
  import javax.xml.stream.events.XMLEvent;
  
  import edu.uci.ics.jung.graph.Hypergraph;
  import edu.uci.ics.jung.io.GraphIOException;
  import edu.uci.ics.jung.io.graphml.ExceptionConverter;
  
  /**
   * Parses an element that just contains text.
   *
   * @author Nathan Mittler - nathan.mittler@gmail.com
   */
  public class StringElementParser<G extends Hypergraph<V,E>,V,E> extends AbstractElementParser<G,V,E> {
  
      public StringElementParser(ParserContext<G,V,E> parserContext) {
          super(parserContext);
      }
      
      public String parse(XMLEventReader xmlEventReader, StartElement start)
              throws GraphIOException {
  
          try {
              String str = null;
  
              while (xmlEventReader.hasNext()) {
  
                  XMLEvent event = xmlEventReader.nextEvent();
                  if (event.isStartElement()) {
  
                      // Parse the unknown element.
                      getUnknownParser().parse(xmlEventReader, event
                              .asStartElement());
                  } else if (event.isEndElement()) {
                      EndElement end = (EndElement) event;
                      verifyMatch(start, end);
                      break;
                  } else if (event.isCharacters()) {
                      Characters characters = (Characters) event;
                      str = characters.getData();
                  }
              }
  
              return str;
  
          } catch (Exception e) {
              ExceptionConverter.convert(e);
          }
  
          return null;
      }
  }