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1   /*
2    $Id: Expando.java,v 1.2 2004/05/15 05:07:13 bran Exp $
3   
4    Copyright 2003 (C) James Strachan and Bob Mcwhirter. All Rights Reserved.
5   
6    Redistribution and use of this software and associated documentation
7    ("Software"), with or without modification, are permitted provided
8    that the following conditions are met:
9   
10   1. Redistributions of source code must retain copyright
11      statements and notices.  Redistributions must also contain a
12      copy of this document.
13  
14   2. Redistributions in binary form must reproduce the
15      above copyright notice, this list of conditions and the
16      following disclaimer in the documentation and/or other
17      materials provided with the distribution.
18  
19   3. The name "groovy" must not be used to endorse or promote
20      products derived from this Software without prior written
21      permission of The Codehaus.  For written permission,
22      please contact info@codehaus.org.
23  
24   4. Products derived from this Software may not be called "groovy"
25      nor may "groovy" appear in their names without prior written
26      permission of The Codehaus. "groovy" is a registered
27      trademark of The Codehaus.
28  
29   5. Due credit should be given to The Codehaus -
30      http://groovy.codehaus.org/
31  
32   THIS SOFTWARE IS PROVIDED BY THE CODEHAUS AND CONTRIBUTORS
33   ``AS IS'' AND ANY EXPRESSED OR IMPLIED WARRANTIES, INCLUDING, BUT
34   NOT LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND
35   FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL
36   THE CODEHAUS OR ITS CONTRIBUTORS BE LIABLE FOR ANY DIRECT,
37   INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
38   (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
39   SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
40   HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT,
41   STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
42   ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED
43   OF THE POSSIBILITY OF SUCH DAMAGE.
44  
45   */
46  package groovy.util;
47  
48  import groovy.lang.Closure;
49  import groovy.lang.GroovyObjectSupport;
50  import groovy.lang.GroovyRuntimeException;
51  
52  import java.util.HashMap;
53  import java.util.Map;
54  
55  
56  /***
57   * Represents a dynamically expandable bean.
58   * 
59   * @author <a href="mailto:james@coredevelopers.net">James Strachan</a>
60   * @version $Revision: 1.2 $
61   */
62  public class Expando extends GroovyObjectSupport {
63  
64      private Map expandoProperties;
65  
66      public Expando() {
67      }
68  
69      public Expando(Map expandoProperties) {
70          this.expandoProperties = expandoProperties;
71      }
72  
73      /***
74       * @return the dynamically expanded properties
75       */
76      public Map getExpandoProperties() {
77          if (expandoProperties == null) {
78              expandoProperties = createMap();
79          }
80          return expandoProperties;
81      }
82  
83      public Object getProperty(String property) {
84          try {
85              return super.getProperty(property);
86          }
87          catch (GroovyRuntimeException e) {
88              return getExpandoProperties().get(property);
89          }
90      }
91  
92      public void setProperty(String property, Object newValue) {
93          try {
94              super.setProperty(property, newValue);
95          }
96          catch (GroovyRuntimeException e) {
97              getExpandoProperties().put(property, newValue);
98          }
99      }
100 
101     public Object invokeMethod(String name, Object args) {
102         try {
103             return super.invokeMethod(name, args);
104         }
105         catch (GroovyRuntimeException e) {
106         	// br should get a "native" property match first. getProperty includes such fall-back logic
107             Object value = this.getProperty(name);
108             if (value instanceof Closure) {
109                 Closure closure = (Closure) value;
110                 closure.setDelegate(this);
111                 return closure.call(args);
112             }
113             else {
114                 throw e;
115             }
116         }
117         
118     }
119     
120     /***
121      * Factory method to create a new Map used to store the expando properties map
122      * @return a newly created Map implementation
123      */
124     protected Map createMap() {
125         return new HashMap();
126     }
127 
128 }