1 package org.codehaus.plexus.metadata.merge.support;
2
3 /*
4 * The MIT License
5 *
6 * Copyright (c) 2006, The Codehaus
7 *
8 * Permission is hereby granted, free of charge, to any person obtaining a copy of
9 * this software and associated documentation files (the "Software"), to deal in
10 * the Software without restriction, including without limitation the rights to
11 * use, copy, modify, merge, publish, distribute, sublicense, and/or sell copies
12 * of the Software, and to permit persons to whom the Software is furnished to do
13 * so, subject to the following conditions:
14 *
15 * The above copyright notice and this permission notice shall be included in all
16 * copies or substantial portions of the Software.
17 *
18 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
19 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
20 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
21 * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
22 * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
23 * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
24 * SOFTWARE.
25 */
26
27 import java.util.Collections;
28 import java.util.List;
29
30 import org.codehaus.plexus.metadata.merge.MergeException;
31 import org.codehaus.plexus.metadata.merge.MergeStrategy;
32
33 /**
34 * Collection of available Merge Strategies.<p>
35 * TODO: Revisit and factor {@link Mergeable#merge(Mergeable)} to use a {@link MergeStrategy}.
36 *
37 * @author <a href='mailto:rahul.thakur.xdev@gmail.com'>Rahul Thakur</a>
38 */
39 public class MergeStrategies {
40 /**
41 * {@link MergeStrategy} implementation wherein the elements are merged
42 * down to the deepest available {@link Mergeable} instance in the DOM tree.
43 */
44 public static final MergeStrategy DEEP = new MergeStrategy() {
45 public void apply(Mergeable dElt, Mergeable rElt) throws MergeException {
46 dElt.merge(rElt);
47 }
48 };
49
50 /**
51 * {@link MergeStrategy} implementation wherein only the element on
52 * which the merge operation is called is 'merged'. The merge does not
53 * traverse the DOM tree any further.
54 */
55 public static final MergeStrategy SHALLOW = new MergeStrategy() {
56 /**
57 * @throws MergeException
58 * @see org.codehaus.plexus.metadata.merge.MergeStrategy#apply(Mergeable,Mergeable)
59 */
60 public void apply(Mergeable dElt, Mergeable rElt) throws MergeException {
61 AbstractMergeableElement dame = (AbstractMergeableElement) dElt;
62 AbstractMergeableElement rame = (AbstractMergeableElement) rElt;
63
64 // check if the dominant was in conflict with recessive.
65 List elementNames = dame.getElementNamesForConflictResolution(Collections.EMPTY_LIST);
66
67 if (!dame.isRecessiveElementInConflict(rame, elementNames)) {
68 // no conflict, simply add recessive to dominant's parent
69 dame.getElement().addContent(rame.getElement());
70 }
71 }
72 };
73 }