ValueExpressionConverter.java

/**
 *   GRANITE DATA SERVICES
 *   Copyright (C) 2006-2015 GRANITE DATA SERVICES S.A.S.
 *
 *   This file is part of the Granite Data Services Platform.
 *
 *   Granite Data Services is free software; you can redistribute it and/or
 *   modify it under the terms of the GNU Lesser General Public
 *   License as published by the Free Software Foundation; either
 *   version 2.1 of the License, or (at your option) any later version.
 *
 *   Granite Data Services is distributed in the hope that it will be useful,
 *   but WITHOUT ANY WARRANTY; without even the implied warranty of
 *   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU Lesser
 *   General Public License for more details.
 *
 *   You should have received a copy of the GNU Lesser General Public
 *   License along with this library; if not, write to the Free Software
 *   Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301,
 *   USA, or see <http://www.gnu.org/licenses/>.
 */
package org.granite.seam21;

import java.lang.reflect.Type;

import org.granite.messaging.amf.io.convert.Converter;
import org.granite.messaging.amf.io.convert.Converters;
import org.granite.messaging.amf.io.convert.Reverter;
import org.granite.util.TypeUtil;
import org.jboss.seam.core.Expressions;
import org.jboss.seam.core.Expressions.ValueExpression;

/**
 * @author William DRAI
 */
public class ValueExpressionConverter extends Converter implements Reverter {
    
    private Expressions expressions = new Expressions();

    public ValueExpressionConverter(Converters converters) {
        super(converters);
    }

    @Override
    protected boolean internalCanConvert(Object value, Type targetType) {
        Class<?> targetClass = TypeUtil.classOfType(targetType);
        return (
            targetClass != Object.class && targetClass.isAssignableFrom(ValueExpression.class) &&
            (value instanceof String || value == null)
        );
    }

    @Override
    protected Object internalConvert(Object value, Type targetType) {
        if (value == null)
            return null;
        return expressions.createValueExpression((String)value);
    }

    public boolean canRevert(Object value) {
        return value instanceof ValueExpression<?>;
    }

    public Object revert(Object value) {
        return ((ValueExpression<?>)value).getExpressionString();
    }

}