001 /* 002 $Id: Binding.java 1590 2005-01-05 14:46:41Z glaforge $ 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.lang; 047 048 import java.util.HashMap; 049 import java.util.Map; 050 051 /** 052 * Represents the variable bindings of a script which can be altered 053 * from outside the script object or created outside of a script and passed 054 * into it. 055 * 056 * @author <a href="mailto:james@coredevelopers.net">James Strachan</a> 057 * @version $Revision: 1590 $ 058 */ 059 public class Binding extends GroovyObjectSupport { 060 private Map variables; 061 062 public Binding() { 063 variables = new HashMap(); 064 } 065 066 public Binding(Map variables) { 067 this.variables = variables; 068 } 069 070 /** 071 * A helper constructor used in main(String[]) method calls 072 * 073 * @param args are the command line arguments from a main() 074 */ 075 public Binding(String[] args) { 076 this(); 077 setVariable("args", args); 078 } 079 080 /** 081 * @param name the name of the variable to lookup 082 * @return the variable value 083 */ 084 public Object getVariable(String name) { 085 Object result = variables.get(name); 086 087 if (result == null && !variables.containsKey(name)) { 088 throw new MissingPropertyException("The property '" + name + "' is missing from the binding.", 089 name, Binding.class); 090 } 091 092 return result; 093 } 094 095 /** 096 * Sets the value of the given variable 097 * @param name the name of the variable to set 098 * @param value the new value for the given variable 099 */ 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 }