001 /* 002 $Id: Expando.java 4578 2006-12-22 11:59:52Z blackdrag $ 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.Closure; 049 import groovy.lang.GroovyObjectSupport; 050 import groovy.lang.GroovyRuntimeException; 051 import groovy.lang.MetaExpandoProperty; 052 import groovy.lang.MissingPropertyException; 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: 4578 $ 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 getProperties() { 085 if (expandoProperties == null) { 086 expandoProperties = createMap(); 087 } 088 return expandoProperties; 089 } 090 091 public List getMetaPropertyValues() { 092 // run through all our current properties and create MetaProperty objects 093 List ret = new ArrayList(); 094 Iterator itr = getProperties().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 // always use the expando properties first 105 Object result = getProperties().get(property); 106 if (result!=null) return result; 107 try { 108 return super.getProperty(property); 109 } 110 catch (MissingPropertyException e) {} 111 return null; 112 } 113 114 public void setProperty(String property, Object newValue) { 115 // always use the expando properties 116 getProperties().put(property, newValue); 117 } 118 119 public Object invokeMethod(String name, Object args) { 120 try { 121 return super.invokeMethod(name, args); 122 } 123 catch (GroovyRuntimeException e) { 124 // br should get a "native" property match first. getProperty includes such fall-back logic 125 Object value = this.getProperty(name); 126 if (value instanceof Closure) { 127 Closure closure = (Closure) value; 128 closure.setDelegate(this); 129 return closure.call((Object[]) args); 130 } 131 else { 132 throw e; 133 } 134 } 135 136 } 137 138 /** 139 * This allows toString to be overridden by a closure <i>field</i> method attached 140 * to the expando object. 141 * 142 * @see java.lang.Object#toString() 143 */ 144 public String toString() { 145 Object method = getProperties().get("toString"); 146 if (method != null && method instanceof Closure) { 147 // invoke overridden toString closure method 148 Closure closure = (Closure) method; 149 closure.setDelegate(this); 150 return closure.call().toString(); 151 } else { 152 return expandoProperties.toString(); 153 } 154 } 155 156 /** 157 * This allows equals to be overridden by a closure <i>field</i> method attached 158 * to the expando object. 159 * 160 * @see java.lang.Object#equals(java.lang.Object) 161 */ 162 public boolean equals(Object obj) { 163 Object method = getProperties().get("equals"); 164 if (method != null && method instanceof Closure) { 165 // invoke overridden equals closure method 166 Closure closure = (Closure) method; 167 closure.setDelegate(this); 168 Boolean ret = (Boolean) closure.call(obj); 169 return ret.booleanValue(); 170 } else { 171 return super.equals(obj); 172 } 173 } 174 175 /** 176 * This allows hashCode to be overridden by a closure <i>field</i> method attached 177 * to the expando object. 178 * 179 * @see java.lang.Object#hashCode() 180 */ 181 public int hashCode() { 182 Object method = getProperties().get("hashCode"); 183 if (method != null && method instanceof Closure) { 184 // invoke overridden hashCode closure method 185 Closure closure = (Closure) method; 186 closure.setDelegate(this); 187 Integer ret = (Integer) closure.call(); 188 return ret.intValue(); 189 } else { 190 return super.hashCode(); 191 } 192 } 193 194 /** 195 * Factory method to create a new Map used to store the expando properties map 196 * @return a newly created Map implementation 197 */ 198 protected Map createMap() { 199 return new HashMap(); 200 } 201 202 }