ELOptionsTag


1   /*
2    * $Id: ELOptionsTag.java 54933 2004-10-16 17:04:52Z 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.strutsel.taglib.html;
20  
21  import org.apache.struts.taglib.html.OptionsTag;
22  import javax.servlet.jsp.JspException  ;
23  import org.apache.strutsel.taglib.utils.EvalHelper;
24  
25  /**
26   * Tag for creating multiple &lt;select&gt; options from a collection.  The
27   * associated values displayed to the user may optionally be specified by a
28   * second collection, or will be the same as the values themselves.  Each
29   * collection may be an array of objects, a Collection, an Enumeration,
30   * an Iterator, or a Map.
31   * <b>NOTE</b> - This tag requires a Java2 (JDK 1.2 or later) platform.
32   *<p>
33   * This class is a subclass of the class
34   * <code>org.apache.struts.taglib.html.OptionsTag</code> which provides most of
35   * the described functionality.  This subclass allows all attribute values to
36   * be specified as expressions utilizing the JavaServer Pages Standard Library
37   * expression language.
38   *
39   * @version $Rev: 54933 $
40   */
41  public class ELOptionsTag extends OptionsTag {
42  
43      /**
44       * Instance variable mapped to "collection" tag attribute.
45       * (Mapping set in associated BeanInfo class.)
46       */
47      private String   collectionExpr;
48      /**
49       * Instance variable mapped to "filter" tag attribute.
50       * (Mapping set in associated BeanInfo class.)
51       */
52      private String   filterExpr;
53      /**
54       * Instance variable mapped to "labelName" tag attribute.
55       * (Mapping set in associated BeanInfo class.)
56       */
57      private String   labelNameExpr;
58      /**
59       * Instance variable mapped to "labelProperty" tag attribute.
60       * (Mapping set in associated BeanInfo class.)
61       */
62      private String   labelPropertyExpr;
63      /**
64       * Instance variable mapped to "name" tag attribute.
65       * (Mapping set in associated BeanInfo class.)
66       */
67      private String   nameExpr;
68      /**
69       * Instance variable mapped to "property" tag attribute.
70       * (Mapping set in associated BeanInfo class.)
71       */
72      private String   propertyExpr;
73      /**
74       * Instance variable mapped to "style" tag attribute.
75       * (Mapping set in associated BeanInfo class.)
76       */
77      private String   styleExpr;
78      /**
79       * Instance variable mapped to "styleClass" tag attribute.
80       * (Mapping set in associated BeanInfo class.)
81       */
82      private String   styleClassExpr;
83  
84      /**
85       * Getter method for "collection" tag attribute.
86       * (Mapping set in associated BeanInfo class.)
87       */
88      public String   getCollectionExpr() { return (collectionExpr); }
89      /**
90       * Getter method for "filter" tag attribute.
91       * (Mapping set in associated BeanInfo class.)
92       */
93      public String   getFilterExpr() { return (filterExpr); }
94      /**
95       * Getter method for "labelName" tag attribute.
96       * (Mapping set in associated BeanInfo class.)
97       */
98      public String   getLabelNameExpr() { return (labelNameExpr); }
99      /**
100      * Getter method for "labelProperty" tag attribute.
101      * (Mapping set in associated BeanInfo class.)
102      */
103     public String   getLabelPropertyExpr() { return (labelPropertyExpr); }
104     /**
105      * Getter method for "name" tag attribute.
106      * (Mapping set in associated BeanInfo class.)
107      */
108     public String   getNameExpr() { return (nameExpr); }
109     /**
110      * Getter method for "property" tag attribute.
111      * (Mapping set in associated BeanInfo class.)
112      */
113     public String   getPropertyExpr() { return (propertyExpr); }
114     /**
115      * Getter method for "style" tag attribute.
116      * (Mapping set in associated BeanInfo class.)
117      */
118     public String   getStyleExpr() { return (styleExpr); }
119     /**
120      * Getter method for "styleClass" tag attribute.
121      * (Mapping set in associated BeanInfo class.)
122      */
123     public String   getStyleClassExpr() { return (styleClassExpr); }
124 
125     /**
126      * Setter method for "collection" tag attribute.
127      * (Mapping set in associated BeanInfo class.)
128      */
129     public void setCollectionExpr(String   collectionExpr) { this.collectionExpr = collectionExpr; }
130     /**
131      * Setter method for "filter" tag attribute.
132      * (Mapping set in associated BeanInfo class.)
133      */
134     public void setFilterExpr(String   filterExpr) { this.filterExpr = filterExpr; }
135     /**
136      * Setter method for "labelName" tag attribute.
137      * (Mapping set in associated BeanInfo class.)
138      */
139     public void setLabelNameExpr(String   labelNameExpr) { this.labelNameExpr = labelNameExpr; }
140     /**
141      * Setter method for "labelProperty" tag attribute.
142      * (Mapping set in associated BeanInfo class.)
143      */
144     public void setLabelPropertyExpr(String   labelPropertyExpr) { this.labelPropertyExpr = labelPropertyExpr; }
145     /**
146      * Setter method for "name" tag attribute.
147      * (Mapping set in associated BeanInfo class.)
148      */
149     public void setNameExpr(String   nameExpr) { this.nameExpr = nameExpr; }
150     /**
151      * Setter method for "property" tag attribute.
152      * (Mapping set in associated BeanInfo class.)
153      */
154     public void setPropertyExpr(String   propertyExpr) { this.propertyExpr = propertyExpr; }
155     /**
156      * Setter method for "style" tag attribute.
157      * (Mapping set in associated BeanInfo class.)
158      */
159     public void setStyleExpr(String   styleExpr) { this.styleExpr = styleExpr; }
160     /**
161      * Setter method for "styleClass" tag attribute.
162      * (Mapping set in associated BeanInfo class.)
163      */
164     public void setStyleClassExpr(String   styleClassExpr) { this.styleClassExpr = styleClassExpr; }
165 
166     /**
167      * Resets attribute values for tag reuse.
168      */
169     public void release()
170     {
171         super.release();
172         setCollectionExpr(null);
173         setFilterExpr(null);
174         setLabelNameExpr(null);
175         setLabelPropertyExpr(null);
176         setNameExpr(null);
177         setPropertyExpr(null);
178         setStyleExpr(null);
179         setStyleClassExpr(null);
180     }
181 
182     /**
183      * Process the start tag.
184      *
185      * @exception JspException if a JSP exception has occurred
186      */
187     public int doStartTag() throws JspException   {
188         evaluateExpressions();
189         return(super.doStartTag());
190     }
191 
192     /**
193      * Processes all attribute values which use the JSTL expression evaluation
194      * engine to determine their values.
195      *
196      * @exception JspException if a JSP exception has occurred
197      */
198     private void evaluateExpressions() throws JspException   {
199         String    string  = null;
200         Boolean   bool    = null;
201 
202         if ((string = EvalHelper.evalString("collection", getCollectionExpr(),
203                                             this, pageContext)) != null)
204             setCollection(string);
205 
206         if ((bool = EvalHelper.evalBoolean("filter", getFilterExpr(),
207                                            this, pageContext)) != null)
208             setFilter(bool.booleanValue());
209 
210         if ((string = EvalHelper.evalString("labelName", getLabelNameExpr(),
211                                             this, pageContext)) != null)
212             setLabelName(string);
213 
214         if ((string = EvalHelper.evalString("labelProperty", getLabelPropertyExpr(),
215                                             this, pageContext)) != null)
216             setLabelProperty(string);
217 
218         if ((string = EvalHelper.evalString("name", getNameExpr(),
219                                             this, pageContext)) != null)
220             setName(string);
221 
222         if ((string = EvalHelper.evalString("property", getPropertyExpr(),
223                                             this, pageContext)) != null)
224             setProperty(string);
225 
226         if ((string = EvalHelper.evalString("style", getStyleExpr(),
227                                             this, pageContext)) != null)
228             setStyle(string);
229 
230         if ((string = EvalHelper.evalString("styleClass", getStyleClassExpr(),
231                                             this, pageContext)) != null)
232             setStyleClass(string);
233 
234         // Note that in contrast to other elements which have "style" and
235         // "styleClass" attributes, this tag does not have a "styleId"
236         // attribute.  This is because this produces the "id" attribute, which
237         // has to be unique document-wide, but this tag can generate more than
238         // one "option" element.  Thus, the base tag, "Options" does not
239         // support this attribute.
240     }
241 }
242
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