Application: gvSIG desktop

/**

 * gvSIG. Desktop Geographic Information System.

 *

 * Copyright (C) 2007-2013 gvSIG Association.

 *

 * This program is free software; you can redistribute it and/or

 * modify it under the terms of the GNU General Public License

 * as published by the Free Software Foundation; either version 3

 * of the License, or (at your option) any later version.

 *

 * This program 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 General Public License for more details.

 *

 * You should have received a copy of the GNU General Public License

 * along with this program; if not, write to the Free Software

 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston,

 * MA  02110-1301, USA.

 *

 * For any additional information, do not hesitate to contact us

 * at info AT gvsig.com, or visit our website www.gvsig.com.

 */

package org.gvsig.expressionevaluator.impl.coercion;

import org.gvsig.expressionevaluator.Expression;

import org.gvsig.tools.dataTypes.CoercionException;

import org.gvsig.tools.dataTypes.DataTypesManager.Coercion;

/**

 * Convert a Expression to String.

 *

 */

public class CoerceToString implements Coercion {

    Coercion previous = null;

    public CoerceToString() {

        // Do nothing

    }

    public CoerceToString(Coercion previous) {

        this.previous = previous;

    }

    @Override

    public Object coerce(Object value) throws CoercionException {

        try {

            if (value == null || value instanceof String) {

                return value;

            }

            if (value instanceof Expression) {

                return ((Expression) value).getPhrase();

            }

            if (previous != null) {

                return previous.coerce(value);

            }

        } catch (Exception e) {

            throw new CoercionException(e);

        }

        throw new CoercionException();

    }

}