/*---------------- FILE HEADER ------------------------------------------
This file is part of deegree.
Copyright (C) 2001-2006 by:
EXSE, Department of Geography, University of Bonn
http://www.giub.uni-bonn.de/deegree/
lat/lon GmbH
http://www.lat-lon.de
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; either
version 2.1 of the License, or (at your option) any later version.
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.
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., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
Contact:
Andreas Poth
lat/lon GmbH
Aennchenstr. 19
53115 Bonn
Germany
E-Mail: poth@lat-lon.de
Prof. Dr. Klaus Greve
Department of Geography
University of Bonn
Meckenheimer Allee 166
53115 Bonn
Germany
E-Mail: greve@giub.uni-bonn.de
---------------------------------------------------------------------------*/
package org.deegree.model.filterencoding;
import java.util.ArrayList;
import java.util.List;
import org.deegree.framework.xml.ElementList;
import org.deegree.framework.xml.XMLTools;
import org.deegree.model.feature.Feature;
import org.w3c.dom.Element;
/**
* Encapsulates the information of a <code>Function</code>element as defined in the
* Expression DTD.
*
* @author Markus Schneider
* @version 07.08.2002
*/
public class Function extends Expression {
/** The Function's name (as specified in it's name attribute). */
private String name;
/** The Function's arguments. */
private List args;
private Function() {
}
/** Constructs a new Function. */
public Function(String name, List args) {
this();
id = ExpressionDefines.FUNCTION;
this.name = name;
this.args = args;
}
/**
* Given a DOM-fragment, a corresponding Expression-object is built. This
* method recursively calls other buildFromDOM () - methods to validate the
* structure of the DOM-fragment.
*
* @throws FilterConstructionException
* if the structure of the DOM-fragment is invalid
*/
public static Expression buildFromDOM(Element element)
throws FilterConstructionException {
// check if root element's name equals 'Function'
if (!element.getLocalName().toLowerCase().equals("function"))
throw new FilterConstructionException(
"Name of element does not equal 'Function'!");
// determine the name of the Function
String name = element.getAttribute("name");
if (name == null)
throw new FilterConstructionException(
"Function's name (-attribute) is unspecified!");
// determine the arguments of the Function
ElementList children = XMLTools.getChildElements(element);
if (children.getLength() < 1)
throw new FilterConstructionException("'" + name
+ "' requires at least 1 element!");
ArrayList args = new ArrayList(children.getLength());
for (int i = 0; i < children.getLength(); i++) {
args.add(Expression.buildFromDOM(children.item(i)));
}
return new Function(name, args);
}
/**
* Returns the Function's name.
*
* @uml.property name="name"
*/
public String getName() {
return name;
}
/**
* @see org.deegree.model.filterencoding.Function#getName()
*
* @uml.property name="name"
*/
public void setName(String name) {
this.name = name;
}
/**
* returns the arguments of the function
*/
public List getArguments() {
return args;
}
/** Produces an indented XML representation of this object. */
public StringBuffer toXML() {
StringBuffer sb = new StringBuffer(1000);
sb.append("<ogc:Function name=\"").append(name).append("\">");
for (int i = 0; i < args.size(); i++) {
Expression expr = (Expression) args.get(i);
sb.append(expr.toXML());
}
sb.append("</ogc:Function>");
return sb;
}
/**
* Returns the <tt>Function</tt>'s value (to be used in the evaluation of
* a complexer <tt>Expression</tt>).
*
* @param feature
* that determines the concrete values of <tt>PropertyNames</tt>
* found in the expression
* @return the resulting value
*/
public Object evaluate(Feature feature) throws FilterEvaluationException {
throw new FilterEvaluationException(
"Function evaluation is not implemented yet!");
}
}/* ********************************************************************
Changes to this class. What the people have been up to:
$Log: Function.java,v $
Revision 1.9 2006/07/12 14:46:14 poth
comment footer added
********************************************************************** */