001    /*
002      GRANITE DATA SERVICES
003      Copyright (C) 2011 GRANITE DATA SERVICES S.A.S.
004    
005      This file is part of Granite Data Services.
006    
007      Granite Data Services is free software; you can redistribute it and/or modify
008      it under the terms of the GNU Library General Public License as published by
009      the Free Software Foundation; either version 2 of the License, or (at your
010      option) any later version.
011    
012      Granite Data Services is distributed in the hope that it will be useful, but
013      WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
014      FITNESS FOR A PARTICULAR PURPOSE. See the GNU Library General Public License
015      for more details.
016    
017      You should have received a copy of the GNU Library General Public License
018      along with this library; if not, see <http://www.gnu.org/licenses/>.
019    */
020    
021    package org.granite.seam21;
022    
023    import java.lang.reflect.Type;
024    
025    import org.granite.messaging.amf.io.convert.Converter;
026    import org.granite.messaging.amf.io.convert.Converters;
027    import org.granite.messaging.amf.io.convert.Reverter;
028    import org.granite.util.ClassUtil;
029    import org.jboss.seam.core.Expressions;
030    import org.jboss.seam.core.Expressions.ValueExpression;
031    
032    /**
033     * @author William DRAI
034     */
035    public class ValueExpressionConverter extends Converter implements Reverter {
036        
037        private Expressions expressions = new Expressions();
038    
039        public ValueExpressionConverter(Converters converters) {
040            super(converters);
041        }
042    
043        @Override
044        protected boolean internalCanConvert(Object value, Type targetType) {
045            Class<?> targetClass = ClassUtil.classOfType(targetType);
046            return (
047                targetClass != Object.class && targetClass.isAssignableFrom(ValueExpression.class) &&
048                (value instanceof String || value == null)
049            );
050        }
051    
052        @Override
053        protected Object internalConvert(Object value, Type targetType) {
054            if (value == null)
055                return null;
056            return expressions.createValueExpression((String)value);
057        }
058    
059        public boolean canRevert(Object value) {
060            return value instanceof ValueExpression<?>;
061        }
062    
063        public Object revert(Object value) {
064            return ((ValueExpression<?>)value).getExpressionString();
065        }
066    
067    }