/*
* The Apache Software License, Version 1.1
*
*
* Copyright (c) 1999-2003 The Apache Software Foundation. All rights
* reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
*
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
*
* 2. 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.
*
* 3. The end-user documentation included with the redistribution,
* if any, must include the following acknowledgment:
* "This product includes software developed by the
* Apache Software Foundation (http://www.apache.org/)."
* Alternately, this acknowledgment may appear in the software itself,
* if and wherever such third-party acknowledgments normally appear.
*
* 4. The names "Xalan" and "Apache Software Foundation" must
* not be used to endorse or promote products derived from this
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*
* 5. Products derived from this software may not be called "Apache",
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*
* THIS SOFTWARE IS PROVIDED ``AS IS'' AND ANY EXPRESSED OR IMPLIED
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* ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
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* 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 Apache Software Foundation and was
* originally based on software copyright (c) 1999, Lotus
* Development Corporation., http://www.lotus.com. For more
* information on the Apache Software Foundation, please see
* <http://www.apache.org/>.
*/
package org.apache.xpath.functions;
import org.apache.xml.dtm.DTM;
import org.apache.xml.dtm.DTMIterator;
import org.apache.xpath.XPathContext;
import org.apache.xpath.axes.SubContextList;
import org.apache.xpath.compiler.Compiler;
import org.apache.xpath.objects.XNumber;
import org.apache.xpath.objects.XObject;
/**
* <meta name="usage" content="advanced"/>
* Execute the Position() function.
*/
public class FuncPosition extends Function
{
private boolean m_isTopLevel;
/**
* Figure out if we're executing a toplevel expression.
* If so, we can't be inside of a predicate.
*/
public void postCompileStep(Compiler compiler)
{
m_isTopLevel = compiler.getLocationPathDepth() == -1;
}
/**
* Get the position in the current context node list.
*
* @param xctxt Runtime XPath context.
*
* @return The current position of the itteration in the context node list,
* or -1 if there is no active context node list.
*/
public int getPositionInContextNodeList(XPathContext xctxt)
{
// System.out.println("FuncPosition- entry");
// If we're in a predicate, then this will return non-null.
SubContextList iter = m_isTopLevel ? null : xctxt.getSubContextList();
if (null != iter)
{
int prox = iter.getProximityPosition(xctxt);
// System.out.println("FuncPosition- prox: "+prox);
return prox;
}
DTMIterator cnl = xctxt.getContextNodeList();
if (null != cnl)
{
int n = cnl.getCurrentNode();
if(n == DTM.NULL)
{
if(cnl.getCurrentPos() == 0)
return 0;
// Then I think we're in a sort. See sort21.xsl. So the iterator has
// already been spent, and is not on the node we're processing.
// It's highly possible that this is an issue for other context-list
// functions. Shouldn't be a problem for last(), and it shouldn't be
// a problem for current().
try
{
cnl = cnl.cloneWithReset();
}
catch(CloneNotSupportedException cnse)
{
throw new org.apache.xml.utils.WrappedRuntimeException(cnse);
}
int currentNode = xctxt.getContextNode();
// System.out.println("currentNode: "+currentNode);
while(DTM.NULL != (n = cnl.nextNode()))
{
if(n == currentNode)
break;
}
}
// System.out.println("n: "+n);
// System.out.println("FuncPosition- cnl.getCurrentPos(): "+cnl.getCurrentPos());
return cnl.getCurrentPos();
}
// System.out.println("FuncPosition - out of guesses: -1");
return -1;
}
/**
* Execute the function. The function must return
* a valid object.
* @param xctxt The current execution context.
* @return A valid XObject.
*
* @throws javax.xml.transform.TransformerException
*/
public XObject execute(XPathContext xctxt) throws javax.xml.transform.TransformerException
{
double pos = (double) getPositionInContextNodeList(xctxt);
return new XNumber(pos);
}
/**
* No arguments to process, so this does nothing.
*/
public void fixupVariables(java.util.Vector vars, int globalsSize)
{
// no-op
}
}