DomTools.java

/**
 * 
 */
package ecologylab.generic;

import org.w3c.dom.NamedNodeMap;
import org.w3c.dom.Node;
import org.w3c.dom.NodeList;

/**
 * Tools for manipulating org.w3c.documents
 * 
 * @author andruid
 */
public class DomTools extends Debug
{
	private static final int	TAB_WIDTH	= 3;
	/**
	 * Print your DOM tree in a readable way.
	 * 
	 * @param node
	 */
  public static void prettyPrint(Node node) 
  {
  	prettyPrint(node, 0);
  }
  private static void prettyPrint(Node node, int level) 
  {
    try 
    {
    	if ("#document".equals(node.getNodeName()))
    	{
    		Node nextChild = node.getFirstChild();
				prettyPrint(nextChild, level);
    		if (nextChild.getNextSibling() != null)
    		{
    			warning(node, "multiple root element!");
    			while (nextChild != null)
    			{
    				prettyPrint(nextChild, level);
    				nextChild = nextChild.getNextSibling();
    			}
    		}
    		return;
    	}
    	for (int i=0; i< level; i++)
    		printTab();
    	
      System.out.print("<" + node.getNodeName());
      NamedNodeMap attrMap = node.getAttributes();
      if (attrMap != null)
	      for (int i = 0; i < attrMap.getLength(); i++) 
	      {
	        Node attr = attrMap.item(i);
	        String attrName = attr.getNodeName();
					System.out.print(" " + attrName + "=\"" + attr.getNodeValue() + '"');
	      }
      String value	= node.getNodeValue();
      if (value != null)
      	System.out.print(value);
      System.out.print(">");

      NodeList nl = node.getChildNodes();
      if (nl != null)
      {
	      int numChildren = nl.getLength();
	      boolean printedNewline	= false;
	      if (numChildren > 0)
	      {
					for (int i = 0; i < numChildren; i++) 
		      {
		        Node childNode = nl.item(i);
		        if ("#text".equals(childNode.getNodeName()))
		        	System.out.print(childNode.getTextContent());
		        else
		        {
		        	if (!printedNewline)
		        	{
		        		printedNewline	= true;
		  	        System.out.print("\n");		        		
		        	}
		        	prettyPrint(childNode, level + 1);		        	
		        }
		      }
		    	for (int i=0; i< level; i++)
		    		printTab();
	      }
      }
      System.out.println("</" + node.getNodeName() + ">");
    } catch (Throwable e) 
    {
      System.out.println("Cannot print!! " + e.getMessage());
      e.printStackTrace();
    }
  }
	private static void printTab()
	{
		for (int i=0; i<TAB_WIDTH; i++)
			System.out.print(' ');
	}

	public static String getAttribute(Node node, String name)
	{
		String result	= null;
		if (node != null)
		{
			Node attrNode	= node.getAttributes().getNamedItem(name);
			if (attrNode != null)
			{
				result			= attrNode.getNodeValue();
			}
		}
		return result;
	}
	
}