source: trunk/gsdl3/src/java/org/greenstone/gsdl3/util/GSXML.java@ 3308

package org.greenstone.gsdl3.util;

import org.w3c.dom.Node;
import org.w3c.dom.Element;
import org.w3c.dom.NodeList;
import org.w3c.dom.Document;
import org.w3c.dom.Text;

import java.util.HashMap;

/** various functions for extracting info out of GS XML */
public class GSXML {

  // takes a node with a resource elements inside it and extracts all the 
  // HASh oids - name att for resource
    public static String [] getResourceNameList(Element content) {
    
    Node n = content.getFirstChild();
    while (n!=null && !n.getNodeName().equals("resourceList")) {
        n = n.getNextSibling();
    }
    if (n==null) { // no docs found
        return null;
    }
        
    NodeList docs = n.getChildNodes();
    
    int numdocs = docs.getLength();
    String []ids = new String[numdocs];
    for (int i=0; i<numdocs; i++) {
        Element e = (Element)docs.item(i);
        String id = e.getAttribute("name");
        // check that its a valid id - ie starts with HASH 
        // need to change this if use different ids
        
        ids[i] = id;
        
    }

    return ids;
    }

    /** extracts metadata names out of an element */
    public static String [] getMetaNameList(Element content) {
    Node n = content.getFirstChild();
    while (n!=null && !n.getNodeName().equals("metadataList")) {
        n = n.getNextSibling();
    }
    if (n==null) { // no metadatas found
        return null;
    }
    NodeList elems = n.getChildNodes();
    
    int numelems = elems.getLength();
    String []ids = new String[numelems];
    for (int i=0; i<numelems; i++) {
        Element e = (Element)elems.item(i);
        String id = e.getAttribute("name");
        ids[i] = id;
    }

    return ids;
    }

    /** takes a paramList element, and gets a HashMap of name-value pairs */
    public static HashMap extractParams(Element xml) {

    if (!xml.getNodeName().equals("paramList")) {
        System.err.println("GSXML:paramList element should have been passed to extractParams, instead it was "+xml.getNodeName());
        return null;
    }
    NodeList params = xml.getChildNodes();
    HashMap param_map = new HashMap();
    for (int i=0; i<params.getLength(); i++) {
        Element param = (Element)params.item(i);
        String name=param.getAttribute("name");
        String value=param.getAttribute("value");
        if (value.equals("")) { // the value is in the content of the param
        value=getNodeText(param); 
        }
        param_map.put(name, value);
        
    }
    return param_map;
    }

    /** extracts the text out of a node */
    public static String getNodeText(Element param) {
    param.normalize();
    Node n = param.getFirstChild();
    while (n!=null && n.getNodeType() !=Node.TEXT_NODE) {
        n=n.getNextSibling();
    }
    if (n==null) { // no text node
        return "";
    }
    return n.getNodeValue();
    }
    /** creates a new document Element */
    public static Element createResourceElement(Document owner, String oid) { 
    Element e = owner.createElement("resource");
    e.setAttribute("name", oid);
    
    return e;
    }
    
    /** add text to a document/subsection  element */
    public static boolean addDocText(Document owner, Element doc, String text) {
    Element content = owner.createElement("content");
    Text t = owner.createTextNode(text);
    content.appendChild(t);
    doc.appendChild(content);
    return true;
    }
    /** adds an empty MetadataList elem to a doc, and returns a ref to it*/
    public static Element addMetaList(Document owner, Element doc) {
    Element list = owner.createElement("metadataList");
    doc.appendChild(list);
    return list;
    }
    /** adds a metadata elem to a list */
    public static boolean addMetadata(Document owner, Element list, 
                      String meta_name, String meta_value) {
    if (meta_value==null || meta_value.equals("")) {
        return false;
    }
    Element data = owner.createElement("metadata");
    data.setAttribute("name", meta_name);
    Text t = owner.createTextNode(meta_value);
    data.appendChild(t);
    list.appendChild(data);
    return true;

    }
}