/*
* GeoTools - The Open Source Java GIS Toolkit
* http://geotools.org
*
* (C) 2002-2008, Open Source Geospatial Foundation (OSGeo)
*
* This library 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;
* version 2.1 of the License.
*
* This library 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.
*/
package org.geotools.filter;
import org.opengis.feature.simple.SimpleFeature;
/**
* Represents a reference to an environmental variable.
* <p>
* The environmental variables are expected to be "understood" by the service making
* use of the Expression. As an example when evaluating an SLD file you can often
* refer to an environmental variable "DPI", for details review the SLD specification.
*
* @author James
*
* @source $URL$
* @deprecated Please use the environmental variable function
*/
public interface EnvironmentVariable extends Expression {
/**
* Gets the attribute value at the path held by this expression from the
* feature.
*
* @param feature the feature to get this attribute from.
*
* @return the value of the attribute found by this expression.
*
* @deprecated use {@link org.opengis.filter.expression.Expression#evaluate(Object)}
*/
Object getValue(SimpleFeature feature);
}