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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 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 var) {
76          this.var = var;
77      }
78  
79  }