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1   /*
2   * The contents of this file are subject to the BT "ZEUS" Open Source 
3   * Licence (L77741), Version 1.0 (the "Licence"); you may not use this file 
4   * except in compliance with the Licence. You may obtain a copy of the Licence
5   * from $ZEUS_INSTALL/licence.html or alternatively from
6   * http://www.labs.bt.com/projects/agents/zeus/licence.htm
7   * 
8   * Except as stated in Clause 7 of the Licence, software distributed under the
9   * Licence is distributed WITHOUT WARRANTY OF ANY KIND, either express or 
10  * implied. See the Licence for the specific language governing rights and 
11  * limitations under the Licence.
12  * 
13  * The Original Code is within the package zeus.*.
14  * The Initial Developer of the Original Code is British Telecommunications
15  * public limited company, whose registered office is at 81 Newgate Street, 
16  * London, EC1A 7AJ, England. Portions created by British Telecommunications 
17  * public limited company are Copyright 1996-9. All Rights Reserved.
18  * 
19  * THIS NOTICE MUST BE INCLUDED ON ANY COPY OF THIS FILE
20  */
21  
22  
23  
24  package zeus.actors;
25  
26  import java.util.*;
27  import zeus.util.*;
28  import zeus.concepts.*;
29  import gnu.regexp.*;
30  
31  
32  public class AttributeNode extends MsgNode {
33     RE value = null;
34     String attribute = null;
35  
36     
37  // meaningless init  to allow rearch
38    public AttributeNode () {
39      ;}
40  
41  
42     AttributeNode(MsgHandler engine, String attribute, RE value) {
43        super(engine);
44        this.attribute = attribute;
45        this.value = value;
46     }
47     void evaluate(String path, Performative input) {
48        Object s = input.getAttribute(attribute);
49        if ( s == null ) s = "";
50        if ( value.isMatch(s.toString()) ) { // was isMatch
51           Core.DEBUG(5,"Matched " + value + " with " + s);
52           propagate(path,input);
53        }
54        else 
55           Core.DEBUG(5,"Matched failed " + value + " <> " + s); 
56     }
57     public boolean equals(Object any) {
58        if ( any instanceof AttributeNode ) {
59           AttributeNode node = (AttributeNode)any;
60           return attribute.equals(node.attribute) && value.equals(node.value);
61        }
62        return false;
63     }
64     void remove(String path) {
65        super.remove(path);
66        if ( use_count == 0 )
67           engine.attributeNodes.removeElement(this);
68     }
69     public String toString() {
70        return "AttributeNode(" + attribute + "," + value + ")";
71     }
72  }