KickJava   Java API By Example, From Geeks To Geeks.

Java > Open Source Codes > org > apache > commons > jelly > tags > core > BreakTag


1 /*
2  * Copyright 2002,2004 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 package org.apache.commons.jelly.tags.core;
17
18 import org.apache.commons.jelly.TagSupport;
19 import org.apache.commons.jelly.XMLOutput;
20 import org.apache.commons.jelly.impl.BreakException;
21 import org.apache.commons.jelly.expression.Expression;
22
23 /**
24  * A tag which terminates the execution of the current <forEach> or ≶while>
25  * loop. This tag can take an optional boolean test attribute which if its true
26  * then the break occurs otherwise the loop continues processing.
27  *
28  * @author <a HREF="mailto:jstrachan@apache.org">James Strachan</a>
29  * @version $Revision: 155420 $
30  */
31 public class BreakTag extends TagSupport {
32
33     /** The expression to evaluate. */
34     private Expression test;
35
36     /**
37      * If specified, the given variable will hold a true/false value
38      * indicating if the loop was broken.
39      */
40     private String JavaDoc var;
41
42     public BreakTag() {
43     }
44
45     // Tag interface
46 //-------------------------------------------------------------------------
47 public void doTag(XMLOutput output) throws BreakException {
48         boolean broken = false;
49         if (test == null || test.evaluateAsBoolean(context)) {
50             broken = true;
51         }
52         if ( var != null ) {
53             context.setVariable( this.var, String.valueOf(broken));
54         }
55         if ( broken ) {
56             throw new BreakException();
57         }
58     }
59
60     /**
61      * Sets the Jelly expression to evaluate (optional).
62      * If this is <code>null</code> or evaluates to
63      * <code>true</code> then the loop is terminated
64      *
65      * @param test the Jelly expression to evaluate
66      */
67     public void setTest(Expression test) {
68         this.test = test;
69     }
70
71     /**
72      * Sets the variable name to export indicating if the item was broken
73      * @param var name of the variable to be exported
74      */
75     public void setVar(String JavaDoc var) {
76         this.var = var;
77     }
78
79 }
80
Popular Tags