1 /*
2 * $Source$
3 * $Revision$
4 *
5 * Copyright (C) 2000 William Chesters
6 *
7 * Part of Melati (http://melati.org), a framework for the rapid
8 * development of clean, maintainable web applications.
9 *
10 * Melati is free software; Permission is granted to copy, distribute
11 * and/or modify this software under the terms either:
12 *
13 * a) the GNU General Public License as published by the Free Software
14 * Foundation; either version 2 of the License, or (at your option)
15 * any later version,
16 *
17 * or
18 *
19 * b) any version of the Melati Software License, as published
20 * at http://melati.org
21 *
22 * You should have received a copy of the GNU General Public License and
23 * the Melati Software License along with this program;
24 * if not, write to the Free Software Foundation, Inc.,
25 * 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA to obtain the
26 * GNU General Public License and visit http://melati.org to obtain the
27 * Melati Software License.
28 *
29 * Feel free to contact the Developers of Melati (http://melati.org),
30 * if you would like to work out a different arrangement than the options
31 * outlined here. It is our intention to allow Melati to be used by as
32 * wide an audience as possible.
33 *
34 * This program is distributed in the hope that it will be useful,
35 * but WITHOUT ANY WARRANTY; without even the implied warranty of
36 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
37 * GNU General Public License for more details.
38 *
39 * Contact details for copyright holder:
40 *
41 * William Chesters <williamc At paneris.org>
42 * http://paneris.org/~williamc
43 * Obrechtstraat 114, 2517VX Den Haag, The Netherlands
44 */
45
46 package org.melati.poem;
47
48 import java.util.Enumeration;
49 import org.melati.poem.util.StringUtils;
50
51 /**
52 * A data type that is a reference to a {@link Persistent} object.
53 */
54 public class ReferencePoemType extends IndexPoemType implements PersistentReferencePoemType {
55
56 private Table<?> targetTable;
57
58 /**
59 * Constructor.
60 *
61 * @param targetTable the Table the type refers to
62 * @param nullable whether this type may contain null values
63 */
64 public ReferencePoemType(Table<?> targetTable, boolean nullable) {
65 super(nullable);
66 if (targetTable == null)
67 throw new NullPointerException();
68 this.targetTable = targetTable;
69 }
70
71 /**
72 * @see org.melati.poem.PersistentReferencePoemType#targetTable()
73 */
74 @Override
75 public Table<?> targetTable() {
76 return targetTable;
77 }
78
79 /**
80 * Returns an <code>Enumeration</code> of the possible raw values.
81 * <p>
82 * In this case the troids of rows in the referenced table.
83 */
84 protected Enumeration<Integer> _possibleRaws() {
85 return targetTable.troidSelection(null, null, false);
86 }
87
88 protected void _assertValidCooked(Object cooked)
89 throws ValidationPoemException {
90 if (!(cooked instanceof Persistent))
91 throw new TypeMismatchPoemException(cooked, this);
92
93 Persistent persistent = (Persistent)cooked;
94
95 if (persistent.getTable() != targetTable)
96 throw new ValidationPoemException(
97 this, persistent,
98 new TableMismatchPoemException(persistent, targetTable));
99 }
100
101 protected Object _cookedOfRaw(Object raw) throws NoSuchRowPoemException {
102 return targetTable.getObject((Integer)raw);
103 }
104
105 protected Integer _rawOfCooked(Object cooked) {
106 return ((Persistent)cooked).troid();
107 }
108
109 protected String _stringOfCooked(Object cooked,
110 PoemLocale locale, int style)
111 throws PoemException {
112 return ((Persistent)cooked).displayString(locale, style);
113 }
114
115 protected boolean _canRepresent(SQLPoemType<?> other) {
116 return
117 other instanceof PersistentReferencePoemType &&
118 ((PersistentReferencePoemType)other).targetTable() == targetTable();
119 }
120
121 protected void _saveColumnInfo(ColumnInfo columnInfo)
122 throws AccessPoemException {
123 columnInfo.setTypefactoryCode(targetTable.tableInfoID());
124 }
125
126 /**
127 * {@inheritDoc}
128 * @see org.melati.poem.BasePoemType#toString()
129 */
130 public String toString() {
131 return
132 "reference to " + targetTable.getName() +
133 " (" + super.toString() + ")";
134 }
135
136 /**
137 * {@inheritDoc}
138 * @see org.melati.poem.PoemType#toDsdType()
139 */
140 public String toDsdType() {
141 return StringUtils.capitalised(targetTable.getName());
142 }
143 }