package org.ximtec.igesture.util;
   
   import java.io.File;
   import java.io.IOException;
   import java.util.ArrayList;
   import java.util.Iterator;
   
   import javax.xml.parsers.DocumentBuilder;
   import javax.xml.parsers.DocumentBuilderFactory;
  import javax.xml.parsers.ParserConfigurationException;
  
  import org.w3c.dom.Document;
  import org.w3c.dom.Element;
  import org.w3c.dom.Node;
  import org.w3c.dom.NodeList;
  import org.xml.sax.SAXException;
  
  /**
   * This class helps with parsing of configuration files.
   * @author Bjorn Puype, bpuype@gmail.com
   *
   */
  public abstract class XMLParser {
  	
  	/**
  	 * Parse an XML file.
  	 * @param fileName	The path of the file to parse.
  	 * @param nodeName	The name of the nodes under the root node (should all be same type).
  	 * @param textNodes	The names of the sub nodes of a node of type nodeName. These nodes should all be text nodes.
  	 * @throws ParserConfigurationException
  	 * @throws SAXException
  	 * @throws IOException
  	 */
  	public void parse(String fileName, String nodeName, ArrayList<String> textNodes) throws ParserConfigurationException, SAXException, IOException
  	{
  		//location of the XML file
  		File file = new File(fileName);
  		//create a XML parser
  		DocumentBuilderFactory dbf = DocumentBuilderFactory.newInstance();
  		DocumentBuilder db;
  		db = dbf.newDocumentBuilder();
  		//parse the XML file and create a DOM tree
  		Document doc = db.parse(file);
  		
  		doc.getDocumentElement().normalize();
  		//get all the nodeName elements
  		NodeList nodeList = doc.getElementsByTagName(nodeName);
  
  		//for all nodeName elements, get all the subelements and put them in a arraylist
  		//then execute the necessary operations on the parsed data
  		for (int i = 0; i < nodeList.getLength(); i++) 
  		{
  		    Node node = nodeList.item(i);
  		    
  		    if (node.getNodeType() == Node.ELEMENT_NODE) 
  		    {
  		    	ArrayList<NodeList> nodeLists = new ArrayList<NodeList>();
  		    	for(Iterator<String> iter = textNodes.iterator(); iter.hasNext(); )
  		    	{
  		    		NodeList nl = ((Element)node).getElementsByTagName(iter.next());
  		    		nodeLists.add(((Element) nl.item(0)).getChildNodes());
  		    	}
  
  			    execute(nodeLists);
  		    }	    
  		}
  	}
  
  	/**
  	 * This method is called for every node of type nodeName. This method has to be implemented to specify what to do with the
  	 * parsed text nodes.
  	 * @param nodeLists	A list with the parsed text nodes.
  	 */
  	public abstract void execute(ArrayList<NodeList> nodeLists);
  	
  }