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Java > Open Source Codes > org > apache > taglibs > xtags > xpath > WhenTag


1 /*
2  * Copyright 1999,2004 The Apache Software Foundation.
3  *
4  * Licensed under the Apache License, Version 2.0 (the "License");
5  * you may not use this file except in compliance with the License.
6  * You may obtain a copy of the License at
7  *
8  * http://www.apache.org/licenses/LICENSE-2.0
9  *
10  * Unless required by applicable law or agreed to in writing, software
11  * distributed under the License is distributed on an "AS IS" BASIS,
12  * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
13  * See the License for the specific language governing permissions and
14  * limitations under the License.
15  */
16
17 package org.apache.taglibs.xtags.xpath;
18
19
20
21 import java.util.List JavaDoc;
22
23 import javax.servlet.jsp.JspException JavaDoc;
24
25 import org.dom4j.Node;
26 import org.dom4j.NodeFilter;
27 import org.dom4j.DocumentHelper;
28
29 /** Behaves like the equivalent XSLT tag.
30   *
31   * @author James Strachan
32   * @version $Revision: 1.2 $
33   */
34 public class WhenTag extends AbstractTag {
35     
36     /** Stores the XPath filter to evaluate */
37     private NodeFilter nodeFilter;
38     
39     //-------------------------------------------------------------------------
40 public WhenTag() {
41     }
42     
43     // BodyTag interface
44 //-------------------------------------------------------------------------
45 public int doStartTag() throws JspException JavaDoc {
46         ChooseTag tag = (ChooseTag) findAncestorWithClass( this, ChooseTag.class );
47         if ( tag != null && ! tag.isEvaluated() ) {
48             if ( evaluate() ) {
49                 tag.setEvaluated(true);
50                 return EVAL_BODY_INCLUDE;
51             }
52         }
53         return SKIP_BODY;
54     }
55     
56     // Properties
57 //-------------------------------------------------------------------------
58 public boolean evaluate() throws JspException JavaDoc {
59         if ( nodeFilter != null ) {
60             return matches( nodeFilter );
61         }
62         return false;
63     }
64
65     public void setTest( String JavaDoc test ) {
66         nodeFilter = createXPathFilter( test );
67     }
68     
69     public void setFilter( NodeFilter nodeFilter ) {
70         this.nodeFilter = nodeFilter;
71     }
72 }
73
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