1 /*
2 * $Id: StrutsTag.java 471754 2006-11-06 14:55:09Z husted $
3 *
4 * Licensed to the Apache Software Foundation (ASF) under one
5 * or more contributor license agreements. See the NOTICE file
6 * distributed with this work for additional information
7 * regarding copyright ownership. The ASF licenses this file
8 * to you under the Apache License, Version 2.0 (the
9 * "License"); you may not use this file except in compliance
10 * with the License. You may obtain a copy of the License at
11 *
12 * http://www.apache.org/licenses/LICENSE-2.0
13 *
14 * Unless required by applicable law or agreed to in writing,
15 * software distributed under the License is distributed on an
16 * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
17 * KIND, either express or implied. See the License for the
18 * specific language governing permissions and limitations
19 * under the License.
20 */
21 package org.apache.struts.taglib.bean;
22
23 import org.apache.struts.config.ModuleConfig;
24 import org.apache.struts.taglib.TagUtils;
25 import org.apache.struts.util.MessageResources;
26
27 import javax.servlet.jsp.JspException;
28 import javax.servlet.jsp.tagext.TagSupport;
29
30 /**
31 * Define a scripting variable that exposes the requested Struts internal
32 * configuraton object.
33 *
34 * @version $Rev: 471754 $ $Date: 2004-10-16 12:38:42 -0400 (Sat, 16 Oct 2004)
35 * $
36 */
37 public class StrutsTag extends TagSupport {
38 /**
39 * The message resources for this package.
40 */
41 protected static MessageResources messages =
42 MessageResources.getMessageResources(
43 "org.apache.struts.taglib.bean.LocalStrings");
44
45 // ------------------------------------------------------------- Properties
46
47 /**
48 * The name of the scripting variable that will be exposed as a page scope
49 * attribute.
50 */
51 protected String id = null;
52
53 /**
54 * The name of the <code>ActionFormBean</code> object to be exposed.
55 */
56 protected String formBean = null;
57
58 /**
59 * The name of the <code>ActionForward</code> object to be exposed.
60 */
61 protected String forward = null;
62
63 /**
64 * The name of the <code>ActionMapping</code> object to be exposed.
65 */
66 protected String mapping = null;
67
68 public String getId() {
69 return (this.id);
70 }
71
72 public void setId(String id) {
73 this.id = id;
74 }
75
76 public String getFormBean() {
77 return (this.formBean);
78 }
79
80 public void setFormBean(String formBean) {
81 this.formBean = formBean;
82 }
83
84 public String getForward() {
85 return (this.forward);
86 }
87
88 public void setForward(String forward) {
89 this.forward = forward;
90 }
91
92 public String getMapping() {
93 return (this.mapping);
94 }
95
96 public void setMapping(String mapping) {
97 this.mapping = mapping;
98 }
99
100 // --------------------------------------------------------- Public Methods
101
102 /**
103 * Retrieve the required configuration object and expose it as a scripting
104 * variable.
105 *
106 * @throws JspException if a JSP exception has occurred
107 */
108 public int doStartTag() throws JspException {
109 // Validate the selector arguments
110 int n = 0;
111
112 if (formBean != null) {
113 n++;
114 }
115
116 if (forward != null) {
117 n++;
118 }
119
120 if (mapping != null) {
121 n++;
122 }
123
124 if (n != 1) {
125 JspException e =
126 new JspException(messages.getMessage("struts.selector"));
127
128 TagUtils.getInstance().saveException(pageContext, e);
129 throw e;
130 }
131
132 // Retrieve our module configuration information
133 ModuleConfig config =
134 TagUtils.getInstance().getModuleConfig(pageContext);
135
136 // Retrieve the requested object to be exposed
137 Object object = null;
138 String selector = null;
139
140 if (formBean != null) {
141 selector = formBean;
142 object = config.findFormBeanConfig(formBean);
143 } else if (forward != null) {
144 selector = forward;
145 object = config.findForwardConfig(forward);
146 } else if (mapping != null) {
147 selector = mapping;
148 object = config.findActionConfig(mapping);
149 }
150
151 if (object == null) {
152 JspException e =
153 new JspException(messages.getMessage("struts.missing", selector));
154
155 TagUtils.getInstance().saveException(pageContext, e);
156 throw e;
157 }
158
159 // Expose this value as a scripting variable
160 pageContext.setAttribute(id, object);
161
162 return (SKIP_BODY);
163 }
164
165 /**
166 * Release all allocated resources.
167 */
168 public void release() {
169 super.release();
170 id = null;
171 formBean = null;
172 forward = null;
173 mapping = null;
174 }
175 }