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    1   /*
    2    $Id: Expando.java,v 1.10 2005/10/03 18:07:36 tug 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   * @author Hein Meling
    66   * @author Pilho Kim
    67   * @version $Revision: 1.10 $
    68   */
    69  public class Expando extends GroovyObjectSupport {
    70
    71      private Map expandoProperties;
    72
    73      public Expando() {
    74      }
    75
    76      public Expando(Map expandoProperties) {
    77          this.expandoProperties = expandoProperties;
    78      }
    79
    80      /***
    81       * @return the dynamically expanded properties
    82       */
    83      public Map getProperties() {
    84          if (expandoProperties == null) {
    85              expandoProperties = createMap();
    86          }
    87          return expandoProperties;
    88      }
    89
    90      public List getMetaPropertyValues() {
    91          // run through all our current properties and create MetaProperty objects
    92          List ret = new ArrayList();
    93          Iterator itr = getProperties().entrySet().iterator();
    94          while(itr.hasNext()) {
    95              Entry entry = (Entry) itr.next();
    96              ret.add(new MetaExpandoProperty(entry));
    97          }
    98
    99          return ret;
    100     }
    101
    102     public Object getProperty(String property) {
    103         try {
    104             return super.getProperty(property);
    105         }
    106         catch (GroovyRuntimeException e) {
    107             return getProperties().get(property);
    108         }
    109     }
    110
    111     public void setProperty(String property, Object newValue) {
    112         try {
    113             super.setProperty(property, newValue);
    114         }
    115         catch (GroovyRuntimeException e) {
    116             getProperties().put(property, newValue);
    117         }
    118     }
    119
    120     public Object invokeMethod(String name, Object args) {
    121         try {
    122             return super.invokeMethod(name, args);
    123         }
    124         catch (GroovyRuntimeException e) {
    125             // br should get a "native" property match first. getProperty includes such fall-back logic
    126             Object value = this.getProperty(name);
    127             if (value instanceof Closure) {
    128                 Closure closure = (Closure) value;
    129                 closure.setDelegate(this);
    130                 return closure.call((Object[]) args);
    131             }
    132             else {
    133                 throw e;
    134             }
    135         }
    136
    137     }
    138
    139     /***
    140      * This allows toString to be overridden by a closure <i>field</i> method attached
    141      * to the expando object.
    142      *
    143      * @see java.lang.Object#toString()
    144      */
    145      public String toString() {
    146         Object method = getProperties().get("toString");
    147         if (method != null && method instanceof Closure) {
    148             // invoke overridden toString closure method
    149             Closure closure = (Closure) method;
    150             closure.setDelegate(this);
    151             return closure.call().toString();
    152         } else {
    153             return expandoProperties.toString();
    154         }
    155      }
    156
    157     /***
    158      * This allows equals to be overridden by a closure <i>field</i> method attached
    159      * to the expando object.
    160      *
    161      * @see java.lang.Object#equals(java.lang.Object)
    162      */
    163     public boolean equals(Object obj) {
    164         Object method = getProperties().get("equals");
    165         if (method != null && method instanceof Closure) {
    166             // invoke overridden equals closure method
    167             Closure closure = (Closure) method;
    168             closure.setDelegate(this);
    169             Boolean ret = (Boolean) closure.call(obj);
    170             return ret.booleanValue();
    171         } else {
    172             return super.equals(obj);
    173         }
    174     }
    175
    176     /***
    177      * This allows hashCode to be overridden by a closure <i>field</i> method attached
    178      * to the expando object.
    179      *
    180      * @see java.lang.Object#hashCode()
    181      */
    182     public int hashCode() {
    183         Object method = getProperties().get("hashCode");
    184         if (method != null && method instanceof Closure) {
    185             // invoke overridden hashCode closure method
    186             Closure closure = (Closure) method;
    187             closure.setDelegate(this);
    188             Integer ret = (Integer) closure.call();
    189             return ret.intValue();
    190         } else {
    191             return super.hashCode();
    192         }
    193     }
    194
    195     /***
    196      * Factory method to create a new Map used to store the expando properties map
    197      * @return a newly created Map implementation
    198      */
    199     protected Map createMap() {
    200         return new HashMap();
    201     }
    202
    203 }