1 package org.apache.velocity.anakia;
2
3 /*
4 * Licensed to the Apache Software Foundation (ASF) under one
5 * or more contributor license agreements. See the NOTICE file
6 * distributed with this work for additional information
7 * regarding copyright ownership. The ASF licenses this file
8 * to you under the Apache License, Version 2.0 (the
9 * "License"); you may not use this file except in compliance
10 * with the License. You may obtain a copy of the License at
11 *
12 * http://www.apache.org/licenses/LICENSE-2.0
13 *
14 * Unless required by applicable law or agreed to in writing,
15 * software distributed under the License is distributed on an
16 * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
17 * KIND, either express or implied. See the License for the
18 * specific language governing permissions and limitations
19 * under the License.
20 */
21
22 import java.util.ArrayList;
23 import java.util.Collection;
24 import java.util.Iterator;
25
26 import org.jdom.Element;
27
28 /**
29 * This class allows you to walk a tree of JDOM Element objects.
30 * It first walks the tree itself starting at the Element passed
31 * into allElements() and stores each node of the tree
32 * in a Vector which allElements() returns as a result of its
33 * execution. You can then use a #foreach in Velocity to walk
34 * over the Vector and visit each Element node. However, you can
35 * achieve the same effect by calling <code>element.selectNodes("//*")</code>.
36 *
37 * @author <a href="mailto:jon@latchkey.com">Jon S. Stevens</a>
38 * @author <a href="mailto:szegedia@freemail.hu">Attila Szegedi</a>
39 * @version $Id: TreeWalker.java 463298 2006-10-12 16:10:32Z henning $
40 */
41 public class TreeWalker
42 {
43 /**
44 * Empty constructor
45 */
46 public TreeWalker()
47 {
48 // Left blank
49 }
50
51 /**
52 * Creates a new Vector and walks the Element tree.
53 *
54 * @param e the starting Element node
55 * @return Vector a vector of Element nodes
56 */
57 public NodeList allElements(Element e)
58 {
59 ArrayList theElements = new ArrayList();
60 treeWalk (e, theElements);
61 return new NodeList(theElements, false);
62 }
63
64 /**
65 * A recursive method to walk the Element tree.
66 * @param Element the current Element
67 */
68 private final void treeWalk(Element e, Collection theElements )
69 {
70 for (Iterator i=e.getChildren().iterator(); i.hasNext(); )
71 {
72 Element child = (Element)i.next();
73 theElements.add(child);
74 treeWalk(child, theElements);
75 }
76 }
77 }