001 /*
002 $Id: Expando.java,v 1.6 2005/07/16 20:00:26 phk Exp $
003
004 Copyright 2003 (C) James Strachan and Bob Mcwhirter. All Rights Reserved.
005
006 Redistribution and use of this software and associated documentation
007 ("Software"), with or without modification, are permitted provided
008 that the following conditions are met:
009
010 1. Redistributions of source code must retain copyright
011 statements and notices. Redistributions must also contain a
012 copy of this document.
013
014 2. Redistributions in binary form must reproduce the
015 above copyright notice, this list of conditions and the
016 following disclaimer in the documentation and/or other
017 materials provided with the distribution.
018
019 3. The name "groovy" must not be used to endorse or promote
020 products derived from this Software without prior written
021 permission of The Codehaus. For written permission,
022 please contact info@codehaus.org.
023
024 4. Products derived from this Software may not be called "groovy"
025 nor may "groovy" appear in their names without prior written
026 permission of The Codehaus. "groovy" is a registered
027 trademark of The Codehaus.
028
029 5. Due credit should be given to The Codehaus -
030 http://groovy.codehaus.org/
031
032 THIS SOFTWARE IS PROVIDED BY THE CODEHAUS AND CONTRIBUTORS
033 ``AS IS'' AND ANY EXPRESSED OR IMPLIED WARRANTIES, INCLUDING, BUT
034 NOT LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND
035 FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL
036 THE CODEHAUS OR ITS CONTRIBUTORS BE LIABLE FOR ANY DIRECT,
037 INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
038 (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
039 SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
040 HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT,
041 STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
042 ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED
043 OF THE POSSIBILITY OF SUCH DAMAGE.
044
045 */
046 package groovy.util;
047
048 import groovy.lang.ParameterArray;
049 import groovy.lang.Closure;
050 import groovy.lang.GroovyObjectSupport;
051 import groovy.lang.GroovyRuntimeException;
052 import groovy.lang.MetaExpandoProperty;
053
054 import java.util.HashMap;
055 import java.util.Map;
056 import java.util.Map.Entry;
057 import java.util.List;
058 import java.util.ArrayList;
059 import java.util.Iterator;
060
061
062 /**
063 * Represents a dynamically expandable bean.
064 *
065 * @author <a href="mailto:james@coredevelopers.net">James Strachan</a>
066 * @author Hein Meling
067 * @author Pilho Kim
068 * @version $Revision: 1.6 $
069 */
070 public class Expando extends GroovyObjectSupport {
071
072 private Map expandoProperties;
073
074 public Expando() {
075 }
076
077 public Expando(Map expandoProperties) {
078 this.expandoProperties = expandoProperties;
079 }
080
081 /**
082 * @return the dynamically expanded properties
083 */
084 public Map getExpandoProperties() {
085 if (expandoProperties == null) {
086 expandoProperties = createMap();
087 }
088 return expandoProperties;
089 }
090
091 public List getProperties() {
092 // run through all our current properties and create MetaProperty objects
093 List ret = new ArrayList();
094 Iterator itr = getExpandoProperties().entrySet().iterator();
095 while(itr.hasNext()) {
096 Entry entry = (Entry) itr.next();
097 ret.add(new MetaExpandoProperty(entry));
098 }
099
100 return ret;
101 }
102
103 public Object getProperty(String property) {
104 try {
105 return super.getProperty(property);
106 }
107 catch (GroovyRuntimeException e) {
108 return getExpandoProperties().get(property);
109 }
110 }
111
112 public void setProperty(String property, Object newValue) {
113 try {
114 super.setProperty(property, newValue);
115 }
116 catch (GroovyRuntimeException e) {
117 getExpandoProperties().put(property, newValue);
118 }
119 }
120
121 public Object invokeMethod(String name, Object args) {
122 try {
123 return super.invokeMethod(name, args);
124 }
125 catch (GroovyRuntimeException e) {
126 // br should get a "native" property match first. getProperty includes such fall-back logic
127 Object value = this.getProperty(name);
128 if (value instanceof Closure) {
129 Closure closure = (Closure) value;
130 closure.setDelegate(this);
131 return closure.call(new ParameterArray(args));
132 }
133 else {
134 throw e;
135 }
136 }
137
138 }
139
140 /**
141 * This allows toString to be overridden by a closure <i>field</i> method attached
142 * to the expando object.
143 *
144 * @see java.lang.Object#toString()
145 */
146 public String toString() {
147 Object method = getExpandoProperties().get("toString");
148 if (method != null && method instanceof Closure) {
149 // invoke overridden toString closure method
150 Closure closure = (Closure) method;
151 closure.setDelegate(this);
152 return closure.call().toString();
153 } else {
154 return expandoProperties.toString();
155 }
156 }
157
158 /**
159 * This allows equals to be overridden by a closure <i>field</i> method attached
160 * to the expando object.
161 *
162 * @see java.lang.Object#equals(java.lang.Object)
163 */
164 public boolean equals(Object obj) {
165 Object method = getExpandoProperties().get("equals");
166 if (method != null && method instanceof Closure) {
167 // invoke overridden equals closure method
168 Closure closure = (Closure) method;
169 closure.setDelegate(this);
170 Boolean ret = (Boolean) closure.call(obj);
171 return ret.booleanValue();
172 } else {
173 return super.equals(obj);
174 }
175 }
176
177 /**
178 * This allows hashCode to be overridden by a closure <i>field</i> method attached
179 * to the expando object.
180 *
181 * @see java.lang.Object#hashCode()
182 */
183 public int hashCode() {
184 Object method = getExpandoProperties().get("hashCode");
185 if (method != null && method instanceof Closure) {
186 // invoke overridden hashCode closure method
187 Closure closure = (Closure) method;
188 closure.setDelegate(this);
189 Integer ret = (Integer) closure.call();
190 return ret.intValue();
191 } else {
192 return super.hashCode();
193 }
194 }
195
196 /**
197 * Factory method to create a new Map used to store the expando properties map
198 * @return a newly created Map implementation
199 */
200 protected Map createMap() {
201 return new HashMap();
202 }
203
204 }