001    /*
002     $Id: AttributeExpression.java,v 1.2 2005/04/08 14:41:27 phk Exp $
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 org.codehaus.groovy.ast.expr;
047    
048    import java.lang.reflect.Field;
049    import java.lang.reflect.Method;
050    import java.lang.reflect.Modifier;
051    
052    import org.codehaus.groovy.ast.GroovyCodeVisitor;
053    import org.codehaus.groovy.classgen.AsmClassGenerator;
054    
055    /**
056     * Represents an attribute access (accessing the field of a class) such as the expression "foo.@bar".
057     * 
058     * @author <a href="mailto:james@coredevelopers.net">James Strachan</a>
059     * @version $Revision: 1.2 $
060     */
061    public class AttributeExpression extends Expression {
062    
063        private Expression objectExpression;
064        private String property;
065        private boolean spreadSafe = false;
066        private boolean safe = false;
067        private boolean isStatic = false;
068    
069        private Method getter = null;
070        private Method setter = null;
071    
072        private Field field = null;
073        private int access = -1;
074    
075        public boolean isStatic() {
076            return isStatic;
077        }
078    
079        public AttributeExpression(Expression objectExpression, String property) {
080            this(objectExpression, property, false);
081        }
082    
083        public AttributeExpression(Expression objectExpression, String property, boolean safe) {
084            this.objectExpression = objectExpression;
085            this.property = property;
086            this.safe = safe;
087        }
088    
089        public void visit(GroovyCodeVisitor visitor) {
090            visitor.visitAttributeExpression(this);
091        }
092    
093        public boolean isDynamic() {
094            return true;
095        }
096    
097        public Expression transformExpression(ExpressionTransformer transformer) {
098            return this;
099        }
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    }