/*

  *  Licensed to the Apache Software Foundation (ASF) under one

  *  or more contributor license agreements.  See the NOTICE file

  *  distributed with this work for additional information

  *  regarding copyright ownership.  The ASF licenses this file

  *  to you under the Apache License, Version 2.0 (the

  *  "License"); you may not use this file except in compliance

  *  with the License.  You may obtain a copy of the License at

  * 

  *  http://www.apache.org/licenses/LICENSE-2.0

  * 

  *  Unless required by applicable law or agreed to in writing,

  *  software distributed under the License is distributed on an

  *  "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY

  *  KIND, either express or implied.  See the License for the

  *  specific language governing permissions and limitations

  *  under the License.

  */

 package org.apache.myfaces.shared_impl.util.xml;

 import org.w3c.dom.Element;

 import org.w3c.dom.Node;

 import org.w3c.dom.NodeList;

 import java.util.ArrayList;

 import java.util.Collections;

 import java.util.List;

 /**

  * @author Manfred Geiler (latest modification by $Author: matzew $)

  * @version $Revision: 557350 $ $Date: 2007-07-18 13:19:50 -0500 (Wed, 18 Jul 2007) $

  */

 public class XmlUtils

 {

     private XmlUtils()

     {

         // hide from public access

     }

     public static String getElementText(Element elem)

     {

         StringBuffer buf = new StringBuffer();

         NodeList nodeList = elem.getChildNodes();

         for (int i = 0, len = nodeList.getLength(); i < len; i++)

         {

             Node n = nodeList.item(i);

             if (n.getNodeType() == Node.TEXT_NODE)

             {

                 buf.append(n.getNodeValue());

             }

             else

             {

                 //TODO see jsf-samples

                 //throw new FacesException("Unexpected node type " + n.getNodeType());

             }

         }

         return buf.toString();

     }

     /**

      * Return content of child element with given tag name.

      * If more than one children with this name are present, the content of the last

      * element is returned.

      *

      * @param elem

      * @param childTagName

      * @return content of child element or null if no child element with this name was found

      */

     public static String getChildText(Element elem, String childTagName)

     {

         NodeList nodeList = elem.getElementsByTagName(childTagName);

         int len = nodeList.getLength();

         if (len == 0)

         {

             return null;

         }

         return getElementText((Element)nodeList.item(len - 1));

    }

     /**

      * Return list of content Strings of all child elements with given tag name.

      * @param elem

      * @param childTagName

      * @return List 

      */

     public static List getChildTextList(Element elem, String childTagName)

     {

         NodeList nodeList = elem.getElementsByTagName(childTagName);

         int len = nodeList.getLength();

         if (len == 0)

         {

             return Collections.EMPTY_LIST;

         }

         List list = new ArrayList(len);

         for (int i = 0; i < len; i++)

         {

             list.add(getElementText((Element)nodeList.item(i)));

         }

         return list;

    }

 }