ContextMatchStepPattern.java revision 9f8118474e9513f7a5b7d2a05e4a0fb15d1a6569 
1/*
2 * Licensed to the Apache Software Foundation (ASF) under one
3 * or more contributor license agreements. See the NOTICE file
4 * distributed with this work for additional information
5 * regarding copyright ownership. The ASF licenses this file
6 * to you under the Apache License, Version 2.0 (the  "License");
7 * you may not use this file except in compliance with the License.
8 * You may obtain a copy of the License at
9 *
10 *     http://www.apache.org/licenses/LICENSE-2.0
11 *
12 * Unless required by applicable law or agreed to in writing, software
13 * distributed under the License is distributed on an "AS IS" BASIS,
14 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
15 * See the License for the specific language governing permissions and
16 * limitations under the License.
17 */
18/*
19 * $Id: ContextMatchStepPattern.java 468655 2006-10-28 07:12:06Z minchau $
20 */
21package org.apache.xpath.patterns;
22
23import org.apache.xml.dtm.Axis;
24import org.apache.xml.dtm.DTM;
25import org.apache.xml.dtm.DTMAxisTraverser;
26import org.apache.xml.dtm.DTMFilter;
27import org.apache.xpath.XPathContext;
28import org.apache.xpath.axes.WalkerFactory;
29import org.apache.xpath.objects.XObject;
30/**
31 * Special context node pattern matcher.
32 */
33public class ContextMatchStepPattern extends StepPattern
34{
35    static final long serialVersionUID = -1888092779313211942L;
36
37  /**
38   * Construct a ContextMatchStepPattern.
39   *
40   */
41  public ContextMatchStepPattern(int axis, int paxis)
42  {
43    super(DTMFilter.SHOW_ALL, axis, paxis);
44  }
45
46  /**
47   * Execute this pattern step, including predicates.
48   *
49   *
50   * @param xctxt XPath runtime context.
51   *
52   * @return {@link org.apache.xpath.patterns.NodeTest#SCORE_NODETEST},
53   *         {@link org.apache.xpath.patterns.NodeTest#SCORE_NONE},
54   *         {@link org.apache.xpath.patterns.NodeTest#SCORE_NSWILD},
55   *         {@link org.apache.xpath.patterns.NodeTest#SCORE_QNAME}, or
56   *         {@link org.apache.xpath.patterns.NodeTest#SCORE_OTHER}.
57   *
58   * @throws javax.xml.transform.TransformerException
59   */
60  public XObject execute(XPathContext xctxt)
61          throws javax.xml.transform.TransformerException
62  {
63
64    if (xctxt.getIteratorRoot() == xctxt.getCurrentNode())
65      return getStaticScore();
66    else
67      return this.SCORE_NONE;
68  }
69
70  /**
71   * Execute the match pattern step relative to another step.
72   *
73   *
74   * @param xctxt The XPath runtime context.
75   * NEEDSDOC @param prevStep
76   *
77   * @return {@link org.apache.xpath.patterns.NodeTest#SCORE_NODETEST},
78   *         {@link org.apache.xpath.patterns.NodeTest#SCORE_NONE},
79   *         {@link org.apache.xpath.patterns.NodeTest#SCORE_NSWILD},
80   *         {@link org.apache.xpath.patterns.NodeTest#SCORE_QNAME}, or
81   *         {@link org.apache.xpath.patterns.NodeTest#SCORE_OTHER}.
82   *
83   * @throws javax.xml.transform.TransformerException
84   */
85  public XObject executeRelativePathPattern(
86          XPathContext xctxt, StepPattern prevStep)
87            throws javax.xml.transform.TransformerException
88  {
89
90    XObject score = NodeTest.SCORE_NONE;
91    int context = xctxt.getCurrentNode();
92    DTM dtm = xctxt.getDTM(context);
93
94    if (null != dtm)
95    {
96      int predContext = xctxt.getCurrentNode();
97      DTMAxisTraverser traverser;
98
99      int axis = m_axis;
100
101      boolean needToTraverseAttrs = WalkerFactory.isDownwardAxisOfMany(axis);
102      boolean iterRootIsAttr = (dtm.getNodeType(xctxt.getIteratorRoot())
103                                 == DTM.ATTRIBUTE_NODE);
104
105      if((Axis.PRECEDING == axis) && iterRootIsAttr)
106      {
107        axis = Axis.PRECEDINGANDANCESTOR;
108      }
109
110      traverser = dtm.getAxisTraverser(axis);
111
112      for (int relative = traverser.first(context); DTM.NULL != relative;
113              relative = traverser.next(context, relative))
114      {
115        try
116        {
117          xctxt.pushCurrentNode(relative);
118
119          score = execute(xctxt);
120
121          if (score != NodeTest.SCORE_NONE)
122          {
123	      //score = executePredicates( xctxt, prevStep, SCORE_OTHER,
124	      //       predContext, relative);
125	      if (executePredicates(xctxt, dtm, context))
126		  return score;
127
128	      score = NodeTest.SCORE_NONE;
129          }
130
131          if(needToTraverseAttrs && iterRootIsAttr
132             && (DTM.ELEMENT_NODE == dtm.getNodeType(relative)))
133          {
134            int xaxis = Axis.ATTRIBUTE;
135            for (int i = 0; i < 2; i++)
136            {
137              DTMAxisTraverser atraverser = dtm.getAxisTraverser(xaxis);
138
139              for (int arelative = atraverser.first(relative);
140                      DTM.NULL != arelative;
141                      arelative = atraverser.next(relative, arelative))
142              {
143                try
144                {
145                  xctxt.pushCurrentNode(arelative);
146
147                  score = execute(xctxt);
148
149                  if (score != NodeTest.SCORE_NONE)
150                  {
151		      //score = executePredicates( xctxt, prevStep, SCORE_OTHER,
152		      //       predContext, arelative);
153
154                    if (score != NodeTest.SCORE_NONE)
155                      return score;
156                  }
157                }
158                finally
159                {
160                  xctxt.popCurrentNode();
161                }
162              }
163              xaxis = Axis.NAMESPACE;
164            }
165          }
166
167        }
168        finally
169        {
170          xctxt.popCurrentNode();
171        }
172      }
173
174    }
175
176    return score;
177  }
178
179}
180