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    1   /*
    2    $Id: Expando.java,v 1.3 2004/07/20 22:26:46 jstump 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;
    54  import java.util.Map;
    55  import java.util.Map.Entry;
    56  import java.util.List;
    57  import java.util.ArrayList;
    58  import java.util.Iterator;
    59
    60
    61  /***
    62   * Represents a dynamically expandable bean.
    63   *
    64   * @author <a href="mailto:james@coredevelopers.net">James Strachan</a>
    65   * @version $Revision: 1.3 $
    66   */
    67  public class Expando extends GroovyObjectSupport {
    68
    69      private Map expandoProperties;
    70
    71      public Expando() {
    72      }
    73
    74      public Expando(Map expandoProperties) {
    75          this.expandoProperties = expandoProperties;
    76      }
    77
    78      /***
    79       * @return the dynamically expanded properties
    80       */
    81      public Map getExpandoProperties() {
    82          if (expandoProperties == null) {
    83              expandoProperties = createMap();
    84          }
    85          return expandoProperties;
    86      }
    87
    88  	public List getProperties() {
    89  		// run through all our current properties and create MetaProperty objects
    90  		List ret = new ArrayList();
    91  		Iterator 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 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     /***
    138      * Factory method to create a new Map used to store the expando properties map
    139      * @return a newly created Map implementation
    140      */
    141     protected Map createMap() {
    142         return new HashMap();
    143     }
    144
    145 }