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1   /*
2    * $Id: ELPutListTag.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.strutsel.taglib.tiles;
22  
23  import org.apache.struts.tiles.taglib.PutListTag;
24  import org.apache.strutsel.taglib.utils.EvalHelper;
25  
26  import javax.servlet.jsp.JspException;
27  
28  /**
29   * PutList tag implementation. <p> This class is a subclass of the class
30   * <code>org.apache.struts.taglib.tiles.PutListTag</code> which provides most
31   * of the described functionality.  This subclass allows all attribute values
32   * to be specified as expressions utilizing the JavaServer Pages Standard
33   * Library expression language.
34   *
35   * @version $Rev: 471754 $
36   */
37  public class ELPutListTag extends PutListTag {
38      /**
39       * Instance variable mapped to "name" tag attribute. (Mapping set in
40       * associated BeanInfo class.)
41       */
42      private String nameExpr;
43  
44      /**
45       * Getter method for "name" tag attribute. (Mapping set in associated
46       * BeanInfo class.)
47       */
48      public String getNameExpr() {
49          return (nameExpr);
50      }
51  
52      /**
53       * Setter method for "name" tag attribute. (Mapping set in associated
54       * BeanInfo class.)
55       */
56      public void setNameExpr(String nameExpr) {
57          this.nameExpr = nameExpr;
58      }
59  
60      /**
61       * Resets attribute values for tag reuse.
62       */
63      public void release() {
64          super.release();
65          setNameExpr(null);
66      }
67  
68      /**
69       * Process the start tag.
70       *
71       * @throws JspException if a JSP exception has occurred
72       */
73      public int doStartTag() throws JspException {
74          evaluateExpressions();
75  
76          return (super.doStartTag());
77      }
78  
79      /**
80       * Processes all attribute values which use the JSTL expression evaluation
81       * engine to determine their values.
82       *
83       * @throws JspException if a JSP exception has occurred
84       */
85      private void evaluateExpressions()
86          throws JspException {
87          String string = null;
88  
89          if ((string =
90                  EvalHelper.evalString("name", getNameExpr(), this, pageContext)) != null) {
91              setName(string);
92          }
93      }
94  }