1. /*
  2. * The Apache Software License, Version 1.1
  3. *
  4. *
  5. * Copyright (c) 1999 The Apache Software Foundation. All rights
  6. * reserved.
  7. *
  8. * Redistribution and use in source and binary forms, with or without
  9. * modification, are permitted provided that the following conditions
  10. * are met:
  11. *
  12. * 1. Redistributions of source code must retain the above copyright
  13. * notice, this list of conditions and the following disclaimer.
  14. *
  15. * 2. Redistributions in binary form must reproduce the above copyright
  16. * notice, this list of conditions and the following disclaimer in
  17. * the documentation and/or other materials provided with the
  18. * distribution.
  19. *
  20. * 3. The end-user documentation included with the redistribution,
  21. * if any, must include the following acknowledgment:
  22. * "This product includes software developed by the
  23. * Apache Software Foundation (http://www.apache.org/)."
  24. * Alternately, this acknowledgment may appear in the software itself,
  25. * if and wherever such third-party acknowledgments normally appear.
  26. *
  27. * 4. The names "Xalan" and "Apache Software Foundation" must
  28. * not be used to endorse or promote products derived from this
  29. * software without prior written permission. For written
  30. * permission, please contact apache@apache.org.
  31. *
  32. * 5. Products derived from this software may not be called "Apache",
  33. * nor may "Apache" appear in their name, without prior written
  34. * permission of the Apache Software Foundation.
  35. *
  36. * THIS SOFTWARE IS PROVIDED ``AS IS'' AND ANY EXPRESSED OR IMPLIED
  37. * WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
  38. * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
  39. * DISCLAIMED. IN NO EVENT SHALL THE APACHE SOFTWARE FOUNDATION OR
  40. * ITS CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
  41. * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
  42. * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF
  43. * USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND
  44. * ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
  45. * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT
  46. * OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  47. * SUCH DAMAGE.
  48. * ====================================================================
  49. *
  50. * This software consists of voluntary contributions made by many
  51. * individuals on behalf of the Apache Software Foundation and was
  52. * originally based on software copyright (c) 1999, Lotus
  53. * Development Corporation., http://www.lotus.com. For more
  54. * information on the Apache Software Foundation, please see
  55. * <http://www.apache.org/>.
  56. */
  57. package org.apache.xpath.functions;
  58. //import org.w3c.dom.Node;
  59. //import org.w3c.dom.traversal.NodeIterator;
  60. import org.apache.xml.dtm.DTM;
  61. import org.apache.xml.dtm.DTMIterator;
  62. import java.util.Vector;
  63. import org.apache.xpath.XPathContext;
  64. import org.apache.xpath.XPath;
  65. import org.apache.xpath.objects.XObject;
  66. import org.apache.xpath.objects.XNumber;
  67. import org.apache.xpath.axes.SubContextList;
  68. import org.apache.xpath.axes.ContextNodeList;
  69. import org.apache.xpath.NodeSetDTM;
  70. import org.apache.xpath.compiler.Compiler;
  71. /**
  72. * <meta name="usage" content="advanced"/>
  73. * Execute the Position() function.
  74. */
  75. public class FuncPosition extends Function
  76. {
  77. private boolean m_isTopLevel;
  78. /**
  79. * Figure out if we're executing a toplevel expression.
  80. * If so, we can't be inside of a predicate.
  81. */
  82. public void postCompileStep(Compiler compiler)
  83. {
  84. m_isTopLevel = compiler.getLocationPathDepth() == -1;
  85. }
  86. /**
  87. * Get the position in the current context node list.
  88. *
  89. * @param xctxt Runtime XPath context.
  90. *
  91. * @return The current position of the itteration in the context node list,
  92. * or -1 if there is no active context node list.
  93. */
  94. public int getPositionInContextNodeList(XPathContext xctxt)
  95. {
  96. // System.out.println("FuncPosition- entry");
  97. // If we're in a predicate, then this will return non-null.
  98. SubContextList iter = m_isTopLevel ? null : xctxt.getSubContextList();
  99. if (null != iter)
  100. {
  101. int prox = iter.getProximityPosition(xctxt);
  102. // System.out.println("FuncPosition- prox: "+prox);
  103. return prox;
  104. }
  105. DTMIterator cnl = xctxt.getContextNodeList();
  106. if (null != cnl)
  107. {
  108. int n = cnl.getCurrentNode();
  109. if(n == DTM.NULL)
  110. {
  111. if(cnl.getCurrentPos() == 0)
  112. return 0;
  113. // Then I think we're in a sort. See sort21.xsl. So the iterator has
  114. // already been spent, and is not on the node we're processing.
  115. // It's highly possible that this is an issue for other context-list
  116. // functions. Shouldn't be a problem for last(), and it shouldn't be
  117. // a problem for current().
  118. try
  119. {
  120. cnl = cnl.cloneWithReset();
  121. }
  122. catch(CloneNotSupportedException cnse)
  123. {
  124. throw new org.apache.xml.utils.WrappedRuntimeException(cnse);
  125. }
  126. int currentNode = xctxt.getContextNode();
  127. // System.out.println("currentNode: "+currentNode);
  128. while(DTM.NULL != (n = cnl.nextNode()))
  129. {
  130. if(n == currentNode)
  131. break;
  132. }
  133. }
  134. // System.out.println("n: "+n);
  135. // System.out.println("FuncPosition- cnl.getCurrentPos(): "+cnl.getCurrentPos());
  136. return cnl.getCurrentPos();
  137. }
  138. // System.out.println("FuncPosition - out of guesses: -1");
  139. return -1;
  140. }
  141. /**
  142. * Execute the function. The function must return
  143. * a valid object.
  144. * @param xctxt The current execution context.
  145. * @return A valid XObject.
  146. *
  147. * @throws javax.xml.transform.TransformerException
  148. */
  149. public XObject execute(XPathContext xctxt) throws javax.xml.transform.TransformerException
  150. {
  151. double pos = (double) getPositionInContextNodeList(xctxt);
  152. return new XNumber(pos);
  153. }
  154. /**
  155. * No arguments to process, so this does nothing.
  156. */
  157. public void fixupVariables(java.util.Vector vars, int globalsSize)
  158. {
  159. // no-op
  160. }
  161. }