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1   /*
2    $Id: AttributeExpression.java,v 1.2 2005/04/08 14:41:27 phk 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
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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 org.codehaus.groovy.ast.expr;
47  
48  import java.lang.reflect.Field;
49  import java.lang.reflect.Method;
50  import java.lang.reflect.Modifier;
51  
52  import org.codehaus.groovy.ast.GroovyCodeVisitor;
53  import org.codehaus.groovy.classgen.AsmClassGenerator;
54  
55  /***
56   * Represents an attribute access (accessing the field of a class) such as the expression "foo.@bar".
57   * 
58   * @author <a href="mailto:james@coredevelopers.net">James Strachan</a>
59   * @version $Revision: 1.2 $
60   */
61  public class AttributeExpression extends Expression {
62  
63      private Expression objectExpression;
64      private String property;
65      private boolean spreadSafe = false;
66      private boolean safe = false;
67      private boolean isStatic = false;
68  
69      private Method getter = null;
70      private Method setter = null;
71  
72      private Field field = null;
73      private int access = -1;
74  
75      public boolean isStatic() {
76          return isStatic;
77      }
78  
79      public AttributeExpression(Expression objectExpression, String property) {
80          this(objectExpression, property, false);
81      }
82  
83      public AttributeExpression(Expression objectExpression, String property, boolean safe) {
84          this.objectExpression = objectExpression;
85          this.property = property;
86          this.safe = safe;
87      }
88  
89      public void visit(GroovyCodeVisitor visitor) {
90          visitor.visitAttributeExpression(this);
91      }
92  
93      public boolean isDynamic() {
94          return true;
95      }
96  
97      public Expression transformExpression(ExpressionTransformer transformer) {
98          return this;
99      }
100 
101     protected void resolveType(AsmClassGenerator resolver) {
102         objectExpression.resolve(resolver);
103         resolver.resolve(this);
104     }
105 
106     public Expression getObjectExpression() {
107         return objectExpression;
108     }
109 
110     public String getProperty() {
111         return property;
112     }
113 
114     public String getText() {
115         return objectExpression.getText() + "." + property;
116     }
117 
118     /***
119      * @return is this a safe navigation, i.e. if true then if the source object is null
120      * then this navigation will return null
121      */
122     public boolean isSafe() {
123         return safe;
124     }
125 
126     public boolean isSpreadSafe() {
127         return spreadSafe;
128     }
129 
130     public void setSpreadSafe(boolean value) {
131         spreadSafe = value;
132     }
133 
134     public String toString() {
135         return super.toString() + "[object: " + objectExpression + " property: " + property + "]";
136     }
137 
138     public void setStatic(boolean aStatic) {
139         this.isStatic = aStatic;
140     }
141 
142     public void setGetter(Method meth) {
143         Class returntype = meth.getReturnType();
144         Class oldType = getTypeClass();
145         if (oldType != null && oldType != Object.class && oldType != returntype) {
146             // something is wrong
147 // in this rare case the getter is discarded. Field access takes over
148 //            String msg = "PropertyExpression.setSetter(): type mismatch: was " + getTypeClass() +
149 //                    ". now " + returntype;
150 //            System.err.println(msg);
151 //            setResolveFailed(true);
152 //            setFailure(msg);
153         }
154         else {
155             getter = meth;
156             setTypeClass(returntype);
157             setTypeResolved(true);
158         }
159     }
160 
161     public Method getGetter() {
162         return getter;
163     }
164 
165     public void setSetter(Method method) {
166         Class paramType = method.getParameterTypes()[0];
167         Class wasType = getTypeClass();
168         if (wasType != null && wasType != Object.class && wasType != paramType) {
169 //            // something is wrong
170 // in this rare case the getter is discarded. Field access takes over
171 //            String msg = "PropertyExpression.setSetter(): type mismatch: was " + getTypeClass() +
172 //                    ". now " + paramType;
173 //            System.err.println(msg);
174 //            setResolveFailed(true);
175 //            setFailure(msg);
176         }
177         else {
178             setter = method;
179             setTypeClass(paramType);
180             setTypeResolved(true);
181         }
182     }
183     public Method getSetter() {
184         return setter;
185     }
186 
187     public void setField(Field fld) {
188         field = fld;
189         setStatic(Modifier.isStatic(fld.getModifiers()));
190         setTypeClass(fld.getType());
191     }
192     public Field getField() {
193         return field;
194     }
195 
196     public void setAccess(int access) {
197         this.access = access;
198     }
199 
200     public int getAccess() {
201         return access;
202     }
203 }