org.apache.xpath.functions.FuncPosition Maven / Gradle / Ivy
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* Licensed to the Apache Software Foundation (ASF) under one
* or more contributor license agreements. See the NOTICE file
* distributed with this work for additional information
* regarding copyright ownership. The ASF licenses this file
* to you under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
/*
* $Id: FuncPosition.java 468655 2006-10-28 07:12:06Z minchau $
*/
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;
/**
* Execute the Position() function.
* @xsl.usage advanced
*/
public class FuncPosition extends Function
{
static final long serialVersionUID = -9092846348197271582L;
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
}
}