1 /*
2 * $Id: ELForwardTag.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.logic;
22
23 import org.apache.struts.taglib.logic.ForwardTag;
24 import org.apache.strutsel.taglib.utils.EvalHelper;
25
26 import javax.servlet.jsp.JspException;
27
28 /**
29 * Perform a forward or redirect to a page that is looked up in the
30 * configuration information associated with our application. <p> This class
31 * is a subclass of the class <code>org.apache.struts.taglib.logix.ForwardTag</code>
32 * which provides most of the described functionality. This subclass allows
33 * all attribute values to be specified as expressions utilizing the
34 * JavaServer Pages Standard Library expression language.
35 *
36 * @version $Rev: 471754 $
37 */
38 public class ELForwardTag extends ForwardTag {
39 /**
40 * Instance variable mapped to "name" tag attribute. (Mapping set in
41 * associated BeanInfo class.)
42 */
43 private String nameExpr;
44
45 /**
46 * Getter method for "name" tag attribute. (Mapping set in associated
47 * BeanInfo class.)
48 */
49 public String getNameExpr() {
50 return (nameExpr);
51 }
52
53 /**
54 * Setter method for "name" tag attribute. (Mapping set in associated
55 * BeanInfo class.)
56 */
57 public void setNameExpr(String nameExpr) {
58 this.nameExpr = nameExpr;
59 }
60
61 /**
62 * Resets attribute values for tag reuse.
63 */
64 public void release() {
65 super.release();
66 setNameExpr(null);
67 }
68
69 /**
70 * Process the start tag.
71 *
72 * @throws JspException if a JSP exception has occurred
73 */
74 public int doStartTag() throws JspException {
75 evaluateExpressions();
76
77 return (super.doStartTag());
78 }
79
80 /**
81 * Processes all attribute values which use the JSTL expression evaluation
82 * engine to determine their values.
83 *
84 * @throws JspException if a JSP exception has occurred
85 */
86 private void evaluateExpressions()
87 throws JspException {
88 String string = null;
89
90 if ((string =
91 EvalHelper.evalString("name", getNameExpr(), this, pageContext)) != null) {
92 setName(string);
93 }
94 }
95 }