001    /*
002     $Id: Expando.java,v 1.4 2005/06/13 06:43:38 glaforge 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.Closure;
049    import groovy.lang.GroovyObjectSupport;
050    import groovy.lang.GroovyRuntimeException;
051    import groovy.lang.MetaExpandoProperty;
052    
053    import java.util.HashMap;
054    import java.util.Map;
055    import java.util.Map.Entry;
056    import java.util.List;
057    import java.util.ArrayList;
058    import java.util.Iterator;
059    
060    
061    /**
062     * Represents a dynamically expandable bean.
063     * 
064     * @author <a href="mailto:james@coredevelopers.net">James Strachan</a>
065     * @version $Revision: 1.4 $
066     */
067    public class Expando extends GroovyObjectSupport {
068    
069        private Map expandoProperties;
070    
071        public Expando() {
072        }
073    
074        public Expando(Map expandoProperties) {
075            this.expandoProperties = expandoProperties;
076        }
077    
078        /**
079         * @return the dynamically expanded properties
080         */
081        public Map getExpandoProperties() {
082            if (expandoProperties == null) {
083                expandoProperties = createMap();
084            }
085            return expandoProperties;
086        }
087            
088            public List getProperties() {
089                    // run through all our current properties and create MetaProperty objects
090                    List ret = new ArrayList();
091                    Iterator itr = getExpandoProperties().entrySet().iterator();
092                    while(itr.hasNext()) {
093                            Entry entry = (Entry) itr.next();
094                            ret.add(new MetaExpandoProperty(entry));
095                    }
096                    
097                    return ret;
098            }
099    
100        public Object getProperty(String 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 property, Object newValue) {
110            try {
111                super.setProperty(property, newValue);
112            }
113            catch (GroovyRuntimeException e) {
114                getExpandoProperties().put(property, newValue);
115            }
116        }
117    
118        public Object invokeMethod(String name, Object 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 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 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 createMap() {
146            return new HashMap();
147        }
148    
149    }