/* Uses a DOM parser to identify the parts of an XML
 * document. The user specifies whether to use a 
 * validating parser.
 */

import org.w3c.dom.Document;
import org.w3c.dom.Element;
import org.w3c.dom.NodeList;
import org.w3c.dom.Node;
import org.w3c.dom.Text;
import javax.xml.parsers.DocumentBuilder;
import javax.xml.parsers.DocumentBuilderFactory;
import java.io.*;

public class Dom {
  public static void main(String[] args) { 
    try {
      DocumentBuilderFactory factory = 
                     DocumentBuilderFactory.newInstance();
      factory.setValidating(false);
      DocumentBuilder builder = factory.newDocumentBuilder();
      Document document = builder.parse(new File("barchart.xml"));
      Element root = document.getDocumentElement();
      root.normalize();
      
      Node titleElement = root.getElementsByTagName("title").item(0);
      String title = titleElement.getFirstChild().getNodeValue();

      NodeList axes = root.getElementsByTagName("axis");
      String x1axis = "";
      String x2axis = "";
      Element temp = (Element) axes.item(0);
      if (temp.getAttribute("variable").equals("x1")) {
      	x1axis = temp.getFirstChild().getNodeValue();      	
      } else {
      	x2axis = temp.getFirstChild().getNodeValue();
      }
      temp = (Element) axes.item(1);
      if (temp.getAttribute("variable").equals("x1")) {
      	x1axis = temp.getFirstChild().getNodeValue();      	
      } else {
      	x2axis = temp.getFirstChild().getNodeValue();
      }  
      
      NodeList datapoints = root.getElementsByTagName("datapoint");    
      for (int i = 0; i < datapoints.getLength(); i++) {
        Element datapoint = (Element)datapoints.item(i);
        Element dataset = (Element) datapoint.getParentNode();
        
        String label = dataset.getAttribute("label");
        String x1 = datapoint.getAttribute("x1");
        String x2 = datapoint.getAttribute("x2");        
		System.out.println(title + " " +
						   label + 
						   " \"" + x1axis + "=" + x1 + "\"" +
						   " \"" + x2axis + "=" + x2 + "\"");
      }
    }catch (Exception e) {
       e.printStackTrace();
    }
  }
}