1 /*
2 * $Source$
3 * $Revision$
4 *
5 * Copyright (C) 2000 Tim Joyce
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 * Tim Joyce <timj At paneris.org>
42 */
43
44 package org.melati.template.webmacro;
45
46 import org.webmacro.PropertyException;
47 import org.webmacro.Context;
48 import org.webmacro.Broker;
49 import org.webmacro.engine.EvaluationExceptionHandler;
50 import org.webmacro.engine.Variable;
51 import org.webmacro.util.Settings;
52
53 /**
54 * An implementation of EvaluationExceptionHandler which throws an exception
55 * whenever it is called.
56 *
57 * This will generally cause the exception to be
58 * displayed to the user -- useful for debugging.
59 *
60 * Modified to allow #if ($null).
61 *
62 * @author Tim Joyce
63 * @since 2001-11-05
64 */
65
66 public class PropagateEvaluationExceptionHandler
67 implements EvaluationExceptionHandler {
68
69 /**
70 * Constructor.
71 */
72 public PropagateEvaluationExceptionHandler() {
73 }
74
75 /**
76 * Forced upon us by the interface, but unused.
77 */
78 @Override
79 public void init(Broker b, Settings config) {
80 }
81
82 @Override
83 public void evaluate(Variable variable,
84 Context context,
85 Exception problem)
86 throws PropertyException {
87 if (problem instanceof PropertyException.NoSuchVariableException
88 || problem instanceof PropertyException.NullValueException
89 || problem instanceof PropertyException.NullToStringException)
90 return;
91 if (problem instanceof PropertyException)
92 throw (PropertyException) problem;
93 else
94 throw new PropertyException("Error evaluating variable "
95 + variable.getVariableName() + ": "
96 + problem, problem);
97 }
98
99 /**
100 * {@inheritDoc}
101 * @see org.webmacro.engine.EvaluationExceptionHandler#expand(
102 * org.webmacro.engine.Variable, org.webmacro.Context, java.lang.Exception)
103 */
104 public String expand(Variable variable,
105 Context context,
106 Exception problem)
107 throws PropertyException {
108 if (problem instanceof PropertyException)
109 throw (PropertyException) problem;
110 else
111 throw new PropertyException("Error evaluating variable "
112 + variable.getVariableName() + ": "
113 + problem, problem);
114 }
115
116
117 /**
118 * {@inheritDoc}
119 * @see org.webmacro.engine.EvaluationExceptionHandler#warningString(java.lang.String)
120 */
121 public String warningString(String warningText) throws PropertyException {
122 throw new PropertyException("Evaluation warning: " + warningText);
123 }
124
125
126 /**
127 * {@inheritDoc}
128 *
129 * I do not believe that this can be exercised, without a bug in webmacro.
130 * @see org.webmacro.engine.EvaluationExceptionHandler#errorString(java.lang.String)
131 */
132 public String errorString(String errorText) throws PropertyException {
133 throw new PropertyException("Evaluation error: " + errorText);
134 }
135 }
136