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 * Licensed to the Apache Software Foundation (ASF) under one
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 * 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,
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/*
 * $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 Also:
  • ChildTestIterator.ChildTestIterator
@xsl.usageadvanced
/** * 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.
/** The traversal axis from where the nodes will be filtered. */
protected int m_axis = -1;
Create a OneStepIterator object.
Params:
  • compiler – A reference to the Compiler that contains the op map.
  • opPos – The position within the op map, which contains the location path expression for this itterator.
Throws:
/** * 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.
Params:
  • axis – One of the org.apache.xml.dtm.Axis integers.
Throws:
/** * 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.
Params:
  • context – The XPath runtime context for this transformation.
/** * 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. // * <p>WARNING: Do not mutate this class from this function!</p> // * @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.
/** * 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.
Returns:Axis.CHILD, etc., or -1 if the axis is not known or is of multiple types.
/** * 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 Also:
  • deepEquals.deepEquals(Expression)
/** * @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; } }