/*
* $Header: /home/projects/jaxen/scm/jaxen/src/java/main/org/jaxen/function/PositionFunction.java,v 1.11 2006/02/05 21:47:41 elharo Exp $
* $Revision: 1.11 $
* $Date: 2006/02/05 21:47:41 $
*
* ====================================================================
*
* Copyright 2000-2002 bob mcwhirter & James Strachan.
* All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions are
* met:
*
* * Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
*
* * Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
*
* * Neither the name of the Jaxen Project nor the names of its
* contributors may be used to endorse or promote products derived
* from this software without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS
* IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
* TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A
* PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER
* OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
* EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
* PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR
* PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF
* LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING
* NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
* SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
*
* ====================================================================
* This software consists of voluntary contributions made by many
* individuals on behalf of the Jaxen Project and was originally
* created by bob mcwhirter <bob@werken.com> and
* James Strachan <jstrachan@apache.org>. For more information on the
* Jaxen Project, please see <http://www.jaxen.org/>.
*
* $Id: PositionFunction.java,v 1.11 2006/02/05 21:47:41 elharo Exp $
*/
package org.orbeon.jaxen.function;
import org.orbeon.jaxen.Context;
import org.orbeon.jaxen.Function;
import org.orbeon.jaxen.FunctionCallException;
import java.util.List;
/**
* <p><b>4.1</b> <code><i>number</i> position()</code></p>
*
*
* <blockquote src="http://www.w3.org/TR/xpath">
* The position function returns a number equal to the context position from the expression evaluation context.
* </blockquote>
*
* @author bob mcwhirter (bob @ werken.com)
* @see <a href="http://www.w3.org/TR/xpath#function-position" target="_top">Section 4.1 of the XPath Specification</a>
*/
public class PositionFunction implements Function
{
/**
* Create a new <code>PositionFunction</code> object.
*/
public PositionFunction() {}
/**
* Returns the position of the context node in the context node-set.
*
* @param context the context at the point in the
* expression where the function is called
* @param args an empty list
*
* @return a <code>Double</code> containing the context position
*
* @throws FunctionCallException if <code>args</code> is not empty
*
* @see Context#getSize()
*/
public Object call(Context context, List args) throws FunctionCallException
{
if ( args.size() == 0 )
{
return evaluate( context );
}
throw new FunctionCallException( "position() does not take any arguments." );
}
/**
*
* Returns the position of the context node in the context node-set.
*
* @param context the context at the point in the
* expression where the function is called
*
* @return a <code>Double</code> containing the context position
*
* @see Context#getPosition()
*/
public static Double evaluate(Context context)
{
return new Double( context.getPosition() );
}
}