1 package org.apache.commons.digester3.examples.plugins.pipeline;
2
3 /*
4 * Licensed to the Apache Software Foundation (ASF) under one or more
5 * contributor license agreements. See the NOTICE file distributed with
6 * this work for additional information regarding copyright ownership.
7 * The ASF licenses this file to You under the Apache License, Version 2.0
8 * (the "License"); you may not use this file except in compliance with
9 * the License. You may obtain a copy of the License at
10 *
11 * http://www.apache.org/licenses/LICENSE-2.0
12 *
13 * Unless required by applicable law or agreed to in writing, software
14 * distributed under the License is distributed on an "AS IS" BASIS,
15 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
16 * See the License for the specific language governing permissions and
17 * limitations under the License.
18 */
19
20 import java.util.LinkedList;
21 import java.util.Iterator;
22
23 import org.apache.commons.digester3.Digester;
24 import org.apache.commons.digester3.plugins.PluginCreateRule;
25
26 /**
27 * An implementation of the Transform interface which is configured with
28 * a sequence of "subtransforms", and applies them one by one to the input
29 * data.
30 * <p>
31 * This demonstrates that a plugged-in class can itself define plugin-points
32 * for user-defined classes if it wishes.
33 */
34 public class CompoundTransform
35 implements Transform
36 {
37
38 private LinkedList<Transform> transforms = new LinkedList<Transform>();
39
40 public void addTransform( Transform transform )
41 {
42 transforms.add( transform );
43 }
44
45 public String transform( String s )
46 {
47 for ( Iterator<Transform> i = transforms.iterator(); i.hasNext(); )
48 {
49 Transform t = i.next();
50 s = t.transform( s );
51 }
52 return s;
53 }
54
55 public static void addRules( Digester d, String patternPrefix )
56 {
57 PluginCreateRule pcr = new PluginCreateRule( Transform.class );
58 d.addRule( patternPrefix + "/subtransform", pcr );
59 d.addSetNext( patternPrefix + "/subtransform", "addTransform" );
60 }
61
62 }