Source code: org/objectstyle/cayenne/access/util/RelationshipDataSource.java
1 /* ====================================================================
2 *
3 * The ObjectStyle Group Software License, Version 1.0
4 *
5 * Copyright (c) 2002-2003 The ObjectStyle Group
6 * and individual authors of the software. All rights reserved.
7 *
8 * Redistribution and use in source and binary forms, with or without
9 * modification, are permitted provided that the following conditions
10 * are met:
11 *
12 * 1. Redistributions of source code must retain the above copyright
13 * notice, this list of conditions and the following disclaimer.
14 *
15 * 2. Redistributions in binary form must reproduce the above copyright
16 * notice, this list of conditions and the following disclaimer in
17 * the documentation and/or other materials provided with the
18 * distribution.
19 *
20 * 3. The end-user documentation included with the redistribution, if
21 * any, must include the following acknowlegement:
22 * "This product includes software developed by the
23 * ObjectStyle Group (http://objectstyle.org/)."
24 * Alternately, this acknowlegement may appear in the software itself,
25 * if and wherever such third-party acknowlegements normally appear.
26 *
27 * 4. The names "ObjectStyle Group" and "Cayenne"
28 * must not be used to endorse or promote products derived
29 * from this software without prior written permission. For written
30 * permission, please contact andrus@objectstyle.org.
31 *
32 * 5. Products derived from this software may not be called "ObjectStyle"
33 * nor may "ObjectStyle" appear in their names without prior written
34 * permission of the ObjectStyle Group.
35 *
36 * THIS SOFTWARE IS PROVIDED ``AS IS'' AND ANY EXPRESSED OR IMPLIED
37 * WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
38 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
39 * DISCLAIMED. IN NO EVENT SHALL THE OBJECTSTYLE GROUP OR
40 * ITS CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
41 * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
42 * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF
43 * USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND
44 * ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
45 * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT
46 * OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
47 * SUCH DAMAGE.
48 * ====================================================================
49 *
50 * This software consists of voluntary contributions made by many
51 * individuals on behalf of the ObjectStyle Group. For more
52 * information on the ObjectStyle Group, please see
53 * <http://objectstyle.org/>.
54 *
55 */
56 package org.objectstyle.cayenne.access.util;
57
58 import java.io.Serializable;
59 import java.util.ArrayList;
60 import java.util.List;
61
62 import org.apache.log4j.Logger;
63 import org.objectstyle.cayenne.access.DataContext;
64 import org.objectstyle.cayenne.access.ToManyList;
65 import org.objectstyle.cayenne.access.ToManyListDataSource;
66 import org.objectstyle.cayenne.query.SelectQuery;
67
68 /**
69 * Default implementation of ToManyListDataSource used to populate
70 * to-many relationships.
71 *
72 * @author Andrei Adamchik
73 */
74 public class RelationshipDataSource implements ToManyListDataSource, Serializable {
75 private static Logger logObj = Logger.getLogger(RelationshipDataSource.class);
76
77 protected DataContext context;
78
79 public RelationshipDataSource(DataContext context) {
80 this.context = context;
81 }
82
83
84 /**
85 * Will fetch to-many relationship destination
86 * objects and update ToManyList with the objects fetched.
87 */
88 public void updateListData(ToManyList list) {
89 if (list.getSrcObjectId().isTemporary())
90 list.setObjectList(new ArrayList());
91 else {
92 SelectQuery sel =
93 QueryUtils.selectRelationshipObjects(
94 context,
95 context.registeredObject(list.getSrcObjectId()),
96 list.getRelName());
97 List results = context.performQuery(sel);
98 list.setObjectList(results);
99 }
100 }
101 }