org.apache.xpath.axes.OneStepIteratorForward Maven / Gradle / Ivy
/*
* 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: OneStepIteratorForward.java 469314 2006-10-30 23:31:59Z minchau $
*/
package org.apache.xpath.axes;
import org.apache.xml.dtm.DTM;
import org.apache.xml.dtm.DTMFilter;
import org.apache.xpath.Expression;
import org.apache.xpath.compiler.Compiler;
import org.apache.xpath.compiler.OpMap;
/**
* This class implements a general iterator for
* those LocationSteps with only one step, and perhaps a predicate,
* that only go forward (i.e. it can not be used with ancestors,
* preceding, etc.)
* @see org.apache.xpath.axes#ChildTestIterator
* @xsl.usage advanced
*/
public class OneStepIteratorForward extends ChildTestIterator
{
static final long serialVersionUID = -1576936606178190566L;
/** The traversal axis from where the nodes will be filtered. */
protected int m_axis = -1;
/**
* Create a OneStepIterator object.
*
* @param compiler A reference to the Compiler that contains the op map.
* @param opPos The position within the op map, which contains the
* location path expression for this itterator.
*
* @throws javax.xml.transform.TransformerException
*/
OneStepIteratorForward(Compiler compiler, int opPos, int analysis)
throws javax.xml.transform.TransformerException
{
super(compiler, opPos, analysis);
int firstStepPos = OpMap.getFirstChildPos(opPos);
m_axis = WalkerFactory.getAxisFromStep(compiler, firstStepPos);
}
/**
* Create a OneStepIterator object that will just traverse the self axes.
*
* @param axis One of the org.apache.xml.dtm.Axis integers.
*
* @throws javax.xml.transform.TransformerException
*/
public OneStepIteratorForward(int axis)
{
super(null);
m_axis = axis;
int whatToShow = DTMFilter.SHOW_ALL;
initNodeTest(whatToShow);
}
/**
* Initialize the context values for this expression
* after it is cloned.
*
* @param context The XPath runtime context for this
* transformation.
*/
public void setRoot(int context, Object environment)
{
super.setRoot(context, environment);
m_traverser = m_cdtm.getAxisTraverser(m_axis);
}
// /**
// * Return the first node out of the nodeset, if this expression is
// * a nodeset expression. This is the default implementation for
// * nodesets.
// * WARNING: Do not mutate this class from this function!
// * @param xctxt The XPath runtime context.
// * @return the first node out of the nodeset, or DTM.NULL.
// */
// public int asNode(XPathContext xctxt)
// throws javax.xml.transform.TransformerException
// {
// if(getPredicateCount() > 0)
// return super.asNode(xctxt);
//
// int current = xctxt.getCurrentNode();
//
// DTM dtm = xctxt.getDTM(current);
// DTMAxisTraverser traverser = dtm.getAxisTraverser(m_axis);
//
// String localName = getLocalName();
// String namespace = getNamespace();
// int what = m_whatToShow;
//
// // System.out.println("what: ");
// // NodeTest.debugWhatToShow(what);
// if(DTMFilter.SHOW_ALL == what
// || ((DTMFilter.SHOW_ELEMENT & what) == 0)
// || localName == NodeTest.WILD
// || namespace == NodeTest.WILD)
// {
// return traverser.first(current);
// }
// else
// {
// int type = getNodeTypeTest(what);
// int extendedType = dtm.getExpandedTypeID(namespace, localName, type);
// return traverser.first(current, extendedType);
// }
// }
/**
* Get the next node via getFirstAttribute && getNextAttribute.
*/
protected int getNextNode()
{
m_lastFetched = (DTM.NULL == m_lastFetched)
? m_traverser.first(m_context)
: m_traverser.next(m_context, m_lastFetched);
return m_lastFetched;
}
/**
* Returns the axis being iterated, if it is known.
*
* @return Axis.CHILD, etc., or -1 if the axis is not known or is of multiple
* types.
*/
public int getAxis()
{
return m_axis;
}
/**
* @see Expression#deepEquals(Expression)
*/
public boolean deepEquals(Expression expr)
{
if(!super.deepEquals(expr))
return false;
if(m_axis != ((OneStepIteratorForward)expr).m_axis)
return false;
return true;
}
}