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Java > Open Source Codes > groovy > util > Expando


1 /*
2  $Id: Expando.java,v 1.4 2005/06/13 06:43:38 glaforge 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 import groovy.lang.MetaExpandoProperty;
52
53 import java.util.HashMap JavaDoc;
54 import java.util.Map JavaDoc;
55 import java.util.Map.Entry;
56 import java.util.List JavaDoc;
57 import java.util.ArrayList JavaDoc;
58 import java.util.Iterator JavaDoc;
59
60
61 /**
62  * Represents a dynamically expandable bean.
63  *
64  * @author <a HREF="mailto:james@coredevelopers.net">James Strachan</a>
65  * @version $Revision: 1.4 $
66  */
67 public class Expando extends GroovyObjectSupport {
68
69     private Map JavaDoc expandoProperties;
70
71     public Expando() {
72     }
73
74     public Expando(Map JavaDoc expandoProperties) {
75         this.expandoProperties = expandoProperties;
76     }
77
78     /**
79      * @return the dynamically expanded properties
80      */
81     public Map JavaDoc getExpandoProperties() {
82         if (expandoProperties == null) {
83             expandoProperties = createMap();
84         }
85         return expandoProperties;
86     }
87     
88     public List JavaDoc getProperties() {
89         // run through all our current properties and create MetaProperty objects
90 List JavaDoc ret = new ArrayList JavaDoc();
91         Iterator JavaDoc itr = getExpandoProperties().entrySet().iterator();
92         while(itr.hasNext()) {
93             Entry entry = (Entry) itr.next();
94             ret.add(new MetaExpandoProperty(entry));
95         }
96         
97         return ret;
98     }
99
100     public Object JavaDoc getProperty(String JavaDoc property) {
101         try {
102             return super.getProperty(property);
103         }
104         catch (GroovyRuntimeException e) {
105             return getExpandoProperties().get(property);
106         }
107     }
108
109     public void setProperty(String JavaDoc property, Object JavaDoc newValue) {
110         try {
111             super.setProperty(property, newValue);
112         }
113         catch (GroovyRuntimeException e) {
114             getExpandoProperties().put(property, newValue);
115         }
116     }
117
118     public Object JavaDoc invokeMethod(String JavaDoc name, Object JavaDoc args) {
119         try {
120             return super.invokeMethod(name, args);
121         }
122         catch (GroovyRuntimeException e) {
123             // br should get a "native" property match first. getProperty includes such fall-back logic
124 Object JavaDoc value = this.getProperty(name);
125             if (value instanceof Closure) {
126                 Closure closure = (Closure) value;
127                 closure.setDelegate(this);
128                 return closure.call(args);
129             }
130             else {
131                 throw e;
132             }
133         }
134         
135     }
136     
137     public String JavaDoc toString() {
138         return expandoProperties.toString();
139     }
140     
141     /**
142      * Factory method to create a new Map used to store the expando properties map
143      * @return a newly created Map implementation
144      */
145     protected Map JavaDoc createMap() {
146         return new HashMap JavaDoc();
147     }
148
149 }
150
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