CheckboxTag


1   /*
2    * $Id: CheckboxTag.java 54929 2004-10-16 16:38:42Z germuska $ 
3    *
4    * Copyright 1999-2004 The Apache Software Foundation.
5    * 
6    * Licensed under the Apache License, Version 2.0 (the "License");
7    * you may not use this file except in compliance with the License.
8    * You may obtain a copy of the License at
9    * 
10   *      http://www.apache.org/licenses/LICENSE-2.0
11   * 
12   * Unless required by applicable law or agreed to in writing, software
13   * distributed under the License is distributed on an "AS IS" BASIS,
14   * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
15   * See the License for the specific language governing permissions and
16   * limitations under the License.
17   */
18  
19  package org.apache.struts.taglib.html;
20  
21  import javax.servlet.jsp.JspException  ;
22  
23  import org.apache.struts.taglib.TagUtils;
24  import org.apache.struts.util.MessageResources;
25  
26  /**
27   * Tag for input fields of type "checkbox".
28   *
29   * @version $Rev: 54929 $ $Date: 2004-10-16 17:38:42 +0100 (Sat, 16 Oct 2004) $
30   */
31  public class CheckboxTag extends BaseHandlerTag {
32  
33      // ----------------------------------------------------- Instance Variables
34  
35      /**
36       * The message resources for this package.
37       */
38      protected static MessageResources messages =
39          MessageResources.getMessageResources(Constants.Package + ".LocalStrings");
40  
41      /**
42       * The name of the bean containing our underlying property.
43       */
44      protected String   name = Constants.BEAN_KEY;
45  
46      public String   getName() {
47          return (this.name);
48      }
49  
50      public void setName(String   name) {
51          this.name = name;
52      }
53  
54      /**
55       * The property name for this field.
56       */
57      protected String   property = null;
58  
59      /**
60       * The body content of this tag (if any).
61       */
62      protected String   text = null;
63  
64      /**
65       * The server value for this option.
66       */
67      protected String   value = null;
68  
69      // ------------------------------------------------------------- Properties
70  
71      /**
72       * Return the property name.
73       */
74      public String   getProperty() {
75  
76          return (this.property);
77  
78      }
79  
80      /**
81       * Set the property name.
82       *
83       * @param property The new property name
84       */
85      public void setProperty(String   property) {
86  
87          this.property = property;
88  
89      }
90  
91      /**
92       * Return the server value.
93       */
94      public String   getValue() {
95  
96          return value == null ? "on" : value;
97  
98      }
99  
100     /**
101      * Set the server value.
102      *
103      * @param value The new server value
104      */
105     public void setValue(String   value) {
106 
107         this.value = value;
108 
109     }
110 
111     // --------------------------------------------------------- Public Methods
112 
113     /**
114      * Generate the required input tag.
115      * <p>
116      * Support for indexed property since Struts 1.1
117      *
118      * @exception JspException if a JSP exception has occurred
119      */
120     public int doStartTag() throws JspException   {
121 
122         // Create an appropriate "input" element based on our parameters
123         StringBuffer   results = new StringBuffer  ("<input type=\"checkbox\"");
124         prepareAttribute(results, "name", prepareName());
125         prepareAttribute(results, "accesskey", getAccesskey());
126         prepareAttribute(results, "tabindex", getTabindex());
127 
128         prepareAttribute(results, "value", getValue());
129         if (isChecked()) {
130             results.append(" checked=\"checked\"");
131         }
132 
133         results.append(prepareEventHandlers());
134         results.append(prepareStyles());
135         prepareOtherAttributes(results);
136         results.append(getElementClose());
137 
138         // Print this field to our output writer
139         TagUtils.getInstance().write(pageContext, results.toString());
140 
141         // Continue processing this page
142         this.text = null;
143         return (EVAL_BODY_TAG);
144 
145     }
146     
147     /**
148      * Determines if the checkbox should be checked.
149      * @return true if checked="checked" should be rendered.
150      * @throws JspException
151      * @since Struts 1.2
152      */
153     protected boolean isChecked() throws JspException   {
154         Object   result =
155             TagUtils.getInstance().lookup(pageContext, name, property, null);
156 
157         if (result == null) {
158             result = "";
159         }
160 
161         result = result.toString();
162 
163         String   checked = (String  ) result;
164         return (
165             checked.equalsIgnoreCase(this.value)
166                 || checked.equalsIgnoreCase("true")
167                 || checked.equalsIgnoreCase("yes")
168                 || checked.equalsIgnoreCase("on"));
169 
170     }
171 
172     /**
173      * Save the associated label from the body content.
174      *
175      * @exception JspException if a JSP exception has occurred
176      */
177     public int doAfterBody() throws JspException   {
178 
179         if (bodyContent != null) {
180             String   value = bodyContent.getString().trim();
181             if (value.length() > 0) {
182                 text = value;
183             }
184         }
185         return (SKIP_BODY);
186 
187     }
188 
189     /**
190      * Process the remainder of this page normally.
191      *
192      * @exception JspException if a JSP exception has occurred
193      */
194     public int doEndTag() throws JspException   {
195 
196         // Render any description for this checkbox
197         if (text != null) {
198             TagUtils.getInstance().write(pageContext, text);
199         }
200 
201         // Evaluate the remainder of this page
202         return (EVAL_PAGE);
203 
204     }
205 
206 
207     /**
208      * Prepare the name element
209      * @return The element name.
210      */
211     protected String   prepareName() throws JspException   {
212 
213         if (property == null) {
214             return null;
215         }
216 
217         // * @since Struts 1.1
218         if(indexed) {
219             StringBuffer   results = new StringBuffer  ();
220             prepareIndex(results, name);
221             results.append(property);
222             return results.toString();
223         }
224 
225         return property;
226 
227     }
228 
229     /**
230      * Release any acquired resources.
231      */
232     public void release() {
233 
234         super.release();
235         name = Constants.BEAN_KEY;
236         property = null;
237         text = null;
238         value = null;
239 
240     }
241 
242 }
243
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