src/org/apache/xpath/patterns/AncestorStepPattern.java

/*
 * The Apache Software License, Version 1.1
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 *
 * Copyright (c) 1999 The Apache Software Foundation.  All rights 
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 *        Apache Software Foundation (http://www.apache.org/)."
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 * ====================================================================
 *
 * 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
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package org.apache.xpath.patterns;

import org.apache.xpath.Expression;
import org.apache.xpath.objects.XObject;
import org.apache.xpath.XPathContext;
import org.apache.xml.utils.PrefixResolver;
import org.apache.xpath.axes.LocPathIterator;

//import org.w3c.dom.Node;
//import org.w3c.dom.traversal.NodeIterator;

import org.apache.xml.dtm.DTM;

/**
 * <meta name="usage" content="advanced"/>
 * Implements a match pattern step that tests an ancestor.
 */
public class AncestorStepPattern extends StepPattern
{

  /**
   * Construct an AncestorStepPattern that tests for namespaces and node names.
   *
   *
   * @param whatToShow Bit set defined mainly by {@link org.w3c.dom.traversal.NodeFilter}.
   * @param namespace The namespace to be tested.
   * @param name The local name to be tested.
   */
  public AncestorStepPattern(int whatToShow, String namespace, String name)
  {
    super(whatToShow, namespace, name);
  }

  /**
   * Construct an AncestorStepPattern that doesn't test for node names.
   *
   *
   * @param whatToShow Bit set defined mainly by {@link org.w3c.dom.traversal.NodeFilter}.
   */
  public AncestorStepPattern(int whatToShow)
  {
    super(whatToShow);
  }

  /**
   * Static calc of match score.
   */
  protected final void calcScore()
  {

    m_score = SCORE_OTHER;

    if (null == m_targetString)
      calcTargetString();
  }

  /**
   * Overide the super method so that we can handle
   * match patterns starting with a function such as id()/
   *
   * @param xctxt XPath runtime context.
   *
   * @return {@link org.apache.xpath.patterns.NodeTest#SCORE_NODETEST}, 
   *         {@link org.apache.xpath.patterns.NodeTest#SCORE_NONE}, 
   *         {@link org.apache.xpath.patterns.NodeTest#SCORE_NSWILD}, 
   *         {@link org.apache.xpath.patterns.NodeTest#SCORE_QNAME}, or
   *         {@link org.apache.xpath.patterns.NodeTest#SCORE_OTHER}.
   *
   * @throws javax.xml.transform.TransformerException
   */
  public XObject execute(XPathContext xctxt) throws javax.xml.transform.TransformerException
  {

    int whatToShow = getWhatToShow();

    if (whatToShow == NodeTest.SHOW_BYFUNCTION)
    {
      XObject score = NodeTest.SCORE_NONE;

      if (null != m_relativePathPattern)
      {
        score = m_relativePathPattern.execute(xctxt);
      }

      return score;
    }
    else
      return super.execute(xctxt);
  }

  /**
   * Execute the match pattern step relative to another step.
   *
   *
   * @param xctxt The XPath runtime context.
   *
   * @return {@link org.apache.xpath.patterns.NodeTest#SCORE_NODETEST}, 
   *         {@link org.apache.xpath.patterns.NodeTest#SCORE_NONE}, 
   *         {@link org.apache.xpath.patterns.NodeTest#SCORE_NSWILD}, 
   *         {@link org.apache.xpath.patterns.NodeTest#SCORE_QNAME}, or
   *         {@link org.apache.xpath.patterns.NodeTest#SCORE_OTHER}.
   *
   * @throws javax.xml.transform.TransformerException
   */
  public XObject executeRelativePathPattern(XPathContext xctxt)
          throws javax.xml.transform.TransformerException
  {

    XObject score = NodeTest.SCORE_NONE;
    int parent = xctxt.getCurrentNode();
    DTM dtm = xctxt.getDTM(parent);
    
    if(null != dtm)
    {
      while (DTM.NULL != (parent = dtm.getParent(parent)))
      {
        try
        {
          xctxt.pushCurrentNode(parent);
  
          score = execute(xctxt);
  
          if (score != NodeTest.SCORE_NONE)
          {
            score = SCORE_OTHER;
  
            break;
          }
        }
        finally
        {
          xctxt.popCurrentNode();
        }
      }
    }

    return score;
  }
}