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1   /*
2    *
3    *   Copyright 2005 The Apache Software Foundation.
4    *
5    *  Licensed under the Apache License, Version 2.0 (the "License");
6    *  you may not use this file except in compliance with the License.
7    *  You may obtain a copy of the License at
8    *
9    *      http://www.apache.org/licenses/LICENSE-2.0
10   *
11   *  Unless required by applicable law or agreed to in writing, software
12   *  distributed under the License is distributed on an "AS IS" BASIS,
13   *  WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
14   *  See the License for the specific language governing permissions and
15   *  limitations under the License.
16   *
17   */
18  package org.apache.commons.scxml.model;
19  
20  import java.util.Collection;
21  
22  import org.apache.commons.scxml.Context;
23  import org.apache.commons.scxml.ErrorReporter;
24  import org.apache.commons.scxml.Evaluator;
25  import org.apache.commons.scxml.EventDispatcher;
26  import org.apache.commons.scxml.SCInstance;
27  import org.apache.commons.scxml.SCXMLExpressionException;
28  
29  /***
30   * The class in this SCXML object model that corresponds to the
31   * <log> SCXML element.
32   *
33   */
34  public class Log extends Action {
35  
36      /***
37       * An expression evaluating to a string to be logged.
38       */
39      private String expr;
40  
41      /***
42       * An expression which returns string which may be used, for example,
43       * to indicate the purpose of the log.
44       */
45      private String label;
46  
47      /***
48       * Constructor.
49       */
50      public Log() {
51          super();
52      }
53  
54      /***
55       * Get the log expression.
56       *
57       * @return Returns the expression.
58       */
59      public final String getExpr() {
60          return expr;
61      }
62  
63      /***
64       * Set the log expression.
65       *
66       * @param expr The expr to set.
67       */
68      public final void setExpr(final String expr) {
69          this.expr = expr;
70      }
71  
72      /***
73       * Get the log label.
74       *
75       * @return Returns the label.
76       */
77      public final String getLabel() {
78          return label;
79      }
80  
81      /***
82       * Set the log label.
83       *
84       * @param label The label to set.
85       */
86      public final void setLabel(final String label) {
87          this.label = label;
88      }
89  
90      /***
91       * {@inheritDoc}
92       */
93      public void execute(final EventDispatcher evtDispatcher,
94              final ErrorReporter errRep, final SCInstance scInstance,
95              final org.apache.commons.logging.Log appLog,
96              final Collection derivedEvents)
97      throws ModelException, SCXMLExpressionException {
98          Context ctx = scInstance.getContext(getParentState());
99          Evaluator eval = scInstance.getEvaluator();
100         appLog.info(label + ": " + String.valueOf(eval.eval(ctx, expr)));
101     }
102 }
103