ELIterateTag


1   /*
2    * $Id: ELIterateTag.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.logic;
20  
21  import org.apache.struts.taglib.logic.IterateTag;
22  import javax.servlet.jsp.JspException  ;
23  import org.apache.strutsel.taglib.utils.EvalHelper;
24  
25  /**
26   * Custom tag that iterates the elements of a collection, which can be
27   * either an attribute or the property of an attribute.  The collection
28   * can be any of the following:  an array of objects, an Enumeration,
29   * an Iterator, a Collection (which includes Lists, Sets and Vectors),
30   * or a Map (which includes Hashtables) whose elements will be iterated over.
31   *<p>
32   * This class is a subclass of the class
33   * <code>org.apache.struts.taglib.logic.IterateTag</code> which provides most of
34   * the described functionality.  This subclass allows all attribute values to
35   * be specified as expressions utilizing the JavaServer Pages Standard Library
36   * expression language.
37   *
38   * @version $Rev: 54933 $
39   */
40  public class ELIterateTag extends IterateTag {
41  
42      /**
43       * Instance variable mapped to "collection" tag attribute.
44       * (Mapping set in associated BeanInfo class.)
45       */
46      private String   collectionExpr;
47      /**
48       * Instance variable mapped to "id" tag attribute.
49       * (Mapping set in associated BeanInfo class.)
50       */
51      private String   idExpr;
52      /**
53       * Instance variable mapped to "indexId" tag attribute.
54       * (Mapping set in associated BeanInfo class.)
55       */
56      private String   indexIdExpr;
57      /**
58       * Instance variable mapped to "length" tag attribute.
59       * (Mapping set in associated BeanInfo class.)
60       */
61      private String   lengthExpr;
62      /**
63       * Instance variable mapped to "name" tag attribute.
64       * (Mapping set in associated BeanInfo class.)
65       */
66      private String   nameExpr;
67      /**
68       * Instance variable mapped to "offset" tag attribute.
69       * (Mapping set in associated BeanInfo class.)
70       */
71      private String   offsetExpr;
72      /**
73       * Instance variable mapped to "property" tag attribute.
74       * (Mapping set in associated BeanInfo class.)
75       */
76      private String   propertyExpr;
77      /**
78       * Instance variable mapped to "scope" tag attribute.
79       * (Mapping set in associated BeanInfo class.)
80       */
81      private String   scopeExpr;
82      /**
83       * Instance variable mapped to "type" tag attribute.
84       * (Mapping set in associated BeanInfo class.)
85       */
86      private String   typeExpr;
87  
88      /**
89       * Getter method for "collection" tag attribute.
90       * (Mapping set in associated BeanInfo class.)
91       */
92      public String   getCollectionExpr() { return (collectionExpr); }
93      /**
94       * Getter method for "id" tag attribute.
95       * (Mapping set in associated BeanInfo class.)
96       */
97      public String   getIdExpr() { return (idExpr); }
98      /**
99       * Getter method for "indexId" tag attribute.
100      * (Mapping set in associated BeanInfo class.)
101      */
102     public String   getIndexIdExpr() { return (indexIdExpr); }
103     /**
104      * Getter method for "length" tag attribute.
105      * (Mapping set in associated BeanInfo class.)
106      */
107     public String   getLengthExpr() { return (lengthExpr); }
108     /**
109      * Getter method for "name" tag attribute.
110      * (Mapping set in associated BeanInfo class.)
111      */
112     public String   getNameExpr() { return (nameExpr); }
113     /**
114      * Getter method for "offset" tag attribute.
115      * (Mapping set in associated BeanInfo class.)
116      */
117     public String   getOffsetExpr() { return (offsetExpr); }
118     /**
119      * Getter method for "property" tag attribute.
120      * (Mapping set in associated BeanInfo class.)
121      */
122     public String   getPropertyExpr() { return (propertyExpr); }
123     /**
124      * Getter method for "scope" tag attribute.
125      * (Mapping set in associated BeanInfo class.)
126      */
127     public String   getScopeExpr() { return (scopeExpr); }
128     /**
129      * Getter method for "type" tag attribute.
130      * (Mapping set in associated BeanInfo class.)
131      */
132     public String   getTypeExpr() { return (typeExpr); }
133 
134     /**
135      * Setter method for "collection" tag attribute.
136      * (Mapping set in associated BeanInfo class.)
137      */
138     public void setCollectionExpr(String   collectionExpr) { this.collectionExpr = collectionExpr; }
139     /**
140      * Setter method for "id" tag attribute.
141      * (Mapping set in associated BeanInfo class.)
142      */
143     public void setIdExpr(String   idExpr) { this.idExpr = idExpr; }
144     /**
145      * Setter method for "indexId" tag attribute.
146      * (Mapping set in associated BeanInfo class.)
147      */
148     public void setIndexIdExpr(String   indexIdExpr) { this.indexIdExpr = indexIdExpr; }
149     /**
150      * Setter method for "length" tag attribute.
151      * (Mapping set in associated BeanInfo class.)
152      */
153     public void setLengthExpr(String   lengthExpr) { this.lengthExpr = lengthExpr; }
154     /**
155      * Setter method for "name" tag attribute.
156      * (Mapping set in associated BeanInfo class.)
157      */
158     public void setNameExpr(String   nameExpr) { this.nameExpr = nameExpr; }
159     /**
160      * Setter method for "offset" tag attribute.
161      * (Mapping set in associated BeanInfo class.)
162      */
163     public void setOffsetExpr(String   offsetExpr) { this.offsetExpr = offsetExpr; }
164     /**
165      * Setter method for "property" tag attribute.
166      * (Mapping set in associated BeanInfo class.)
167      */
168     public void setPropertyExpr(String   propertyExpr) { this.propertyExpr = propertyExpr; }
169     /**
170      * Setter method for "scope" tag attribute.
171      * (Mapping set in associated BeanInfo class.)
172      */
173     public void setScopeExpr(String   scopeExpr) { this.scopeExpr = scopeExpr; }
174     /**
175      * Setter method for "type" tag attribute.
176      * (Mapping set in associated BeanInfo class.)
177      */
178     public void setTypeExpr(String   typeExpr) { this.typeExpr = typeExpr; }
179 
180     /**
181      * Releases state of custom tag so this instance can be reused.
182      */
183     public void release()
184     {
185         super.release();
186         setCollectionExpr(null);
187         setIdExpr(null);
188         setIndexIdExpr(null);
189         setLengthExpr(null);
190         setNameExpr(null);
191         setOffsetExpr(null);
192         setPropertyExpr(null);
193         setScopeExpr(null);
194         setTypeExpr(null);
195     }
196 
197     /**
198      * Process the start tag.
199      *
200      * @exception JspException if a JSP exception has occurred
201      */
202     public int doStartTag() throws JspException   {
203         evaluateExpressions();
204         return(super.doStartTag());
205     }
206 
207     /**
208      * Processes all attribute values which use the JSTL expression evaluation
209      * engine to determine their values.
210      *
211      * @exception JspException if a JSP exception has occurred
212      */
213     private void evaluateExpressions() throws JspException   {
214         String   string   = null;
215         Object   object   = null;
216 
217         if ((object = EvalHelper.eval("collection", getCollectionExpr(),
218                                       this, pageContext)) != null)
219             setCollection(object);
220 
221         if ((string = EvalHelper.evalString("id", getIdExpr(),
222                                             this, pageContext)) != null)
223             setId(string);
224 
225         if ((string = EvalHelper.evalString("indexId", getIndexIdExpr(),
226                                             this, pageContext)) != null)
227             setIndexId(string);
228 
229         if ((string = EvalHelper.evalString("length", getLengthExpr(),
230                                             this, pageContext)) != null)
231             setLength(string);
232 
233         if ((string = EvalHelper.evalString("name", getNameExpr(),
234                                             this, pageContext)) != null)
235             setName(string);
236 
237         if ((string = EvalHelper.evalString("offset", getOffsetExpr(),
238                                             this, pageContext)) != null)
239             setOffset(string);
240 
241         if ((string = EvalHelper.evalString("property", getPropertyExpr(),
242                                             this, pageContext)) != null)
243             setProperty(string);
244 
245         if ((string = EvalHelper.evalString("scope", getScopeExpr(),
246                                             this, pageContext)) != null)
247             setScope(string);
248 
249         if ((string = EvalHelper.evalString("type", getTypeExpr(),
250                                             this, pageContext)) != null)
251             setType(string);
252     }
253 }
254
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