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    1   /*
    2    $Id: Binding.java,v 1.5 2005/01/05 14:46:41 glaforge 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.lang;
    47
    48  import java.util.HashMap;
    49  import java.util.Map;
    50
    51  /***
    52   * Represents the variable bindings of a script which can be altered
    53   * from outside the script object or created outside of a script and passed
    54   * into it.
    55   *
    56   * @author <a href="mailto:james@coredevelopers.net">James Strachan</a>
    57   * @version $Revision: 1.5 $
    58   */
    59  public class Binding extends GroovyObjectSupport {
    60      private Map variables;
    61
    62      public Binding() {
    63          variables = new HashMap();
    64      }
    65
    66      public Binding(Map variables) {
    67          this.variables = variables;
    68      }
    69
    70      /***
    71       * A helper constructor used in main(String[]) method calls
    72       *
    73       * @param args are the command line arguments from a main()
    74       */
    75      public Binding(String[] args) {
    76          this();
    77          setVariable("args", args);
    78      }
    79
    80      /***
    81       * @param name the name of the variable to lookup
    82       * @return the variable value
    83       */
    84      public Object getVariable(String name) {
    85          Object result = variables.get(name);
    86
    87          if (result == null && !variables.containsKey(name)) {
    88              throw new MissingPropertyException("The property '" + name + "' is missing from the binding.",
    89                                                 name, Binding.class);
    90          }
    91
    92          return result;
    93      }
    94
    95      /***
    96       * Sets the value of the given variable
    97       * @param name the name of the variable to set
    98       * @param value the new value for the given variable
    99       */
    100     public void setVariable(String name, Object value) {
    101         variables.put(name, value);
    102     }
    103
    104     public Map getVariables() {
    105         return variables;
    106     }
    107
    108     /***
    109      * Overloaded to make variables appear as bean properties or via the subscript operator
    110      */
    111     public Object getProperty(String property) {
    112         /*** @todo we should check if we have the property with the metaClass instead of try/catch  */
    113         try {
    114             return super.getProperty(property);
    115         }
    116         catch (MissingPropertyException e) {
    117             return getVariable(property);
    118         }
    119     }
    120
    121     /***
    122      * Overloaded to make variables appear as bean properties or via the subscript operator
    123      */
    124     public void setProperty(String property, Object newValue) {
    125         /*** @todo we should check if we have the property with the metaClass instead of try/catch  */
    126         try {
    127             super.setProperty(property, newValue);
    128         }
    129         catch (MissingPropertyException e) {
    130             setVariable(property, newValue);
    131         }
    132     }
    133
    134 }