package net.programmera.www.dom;

import javax.xml.parsers.DocumentBuilderFactory;
import javax.xml.parsers.DocumentBuilder;

import org.w3c.dom.Attr;
import org.w3c.dom.Document;
import org.w3c.dom.NamedNodeMap;
import org.w3c.dom.NodeList;
import org.w3c.dom.Node;
import org.w3c.dom.Text;

public class MyDOMParser {

	/**
	* parse
	*
	* This method will parse a XML-document and return a Document.
	*
	* Arguments:
	* url= The URL where to find the XML-document to be parsed. 
	*/

	public Document parse(String url){
	   try{
		DocumentBuilderFactory dbf= DocumentBuilderFactory.newInstance();
		DocumentBuilder db= dbf.newDocumentBuilder();
		Document doc= db.parse(url);
	 	return doc;
	   }catch(Exception e){
		System.out.print(e);
                return null;
	   }
	}

	/** 
	* getStructure 
	*
	* This method will return the structure of a Document.
	*
	* Arguments:
	* doc= a Document. 
	*/

	public String getStructure(Document doc){
		Node n= doc.getDocumentElement();
		String outStr= getElement(n,0);
		return outStr;
		
	}
	
        /** 
        * getElement 
        *
        * Helper method.
        *
        */
	private String getElement(Node n, int level){
		String baseStr="";
		// 0. Indent the text
		for(int i=0; i< level; i++){
			baseStr+="__";
		}

		// 1. Output the element name
		String outStr=baseStr+"ELEMENT="+n.getNodeName();

		// 2. Output attributes
		if(n.hasAttributes()){
			NamedNodeMap nnm= n.getAttributes();
			for(int i=0; i< nnm.getLength(); i++){
				Attr a = (Attr) nnm.item(i);
				outStr+="#"+baseStr+"__ATTR="+a.getName()+" VAL="+a.getValue()+"=";
			}	
		}	

		// 3. Output the children
		if(n.hasChildNodes()){
 			NodeList nl = n.getChildNodes();
			for(int i=0; i < nl.getLength(); i++ ){
				Node childNode = nl.item(i);
				if(childNode.getNodeType()== Node.ELEMENT_NODE){
					outStr+= "#"+ getElement(childNode, level+1);	
				}else if(childNode.getNodeType()== Node.TEXT_NODE){
                                        Text tn = (Text) childNode;
					outStr+= "#"+ baseStr + "__TEXT=" + tn.getData()+"=";
				}
			}
		}
                return outStr;
    
        }
}