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: FuncPosition.java 468655 2006-10-28 07:12:06Z minchau $ 20 */ 21 package org.apache.xpath.functions; 22 23 import org.apache.xml.dtm.DTM; 24 import org.apache.xml.dtm.DTMIterator; 25 import org.apache.xpath.XPathContext; 26 import org.apache.xpath.axes.SubContextList; 27 import org.apache.xpath.compiler.Compiler; 28 import org.apache.xpath.objects.XNumber; 29 import org.apache.xpath.objects.XObject; 30 31 /** 32 * Execute the Position() function. 33 * @xsl.usage advanced 34 */ 35 public class FuncPosition extends Function 36 { 37 static final long serialVersionUID = -9092846348197271582L; 38 private boolean m_isTopLevel; 39 40 /** 41 * Figure out if we're executing a toplevel expression. 42 * If so, we can't be inside of a predicate. 43 */ postCompileStep(Compiler compiler)44 public void postCompileStep(Compiler compiler) 45 { 46 m_isTopLevel = compiler.getLocationPathDepth() == -1; 47 } 48 49 /** 50 * Get the position in the current context node list. 51 * 52 * @param xctxt Runtime XPath context. 53 * 54 * @return The current position of the itteration in the context node list, 55 * or -1 if there is no active context node list. 56 */ getPositionInContextNodeList(XPathContext xctxt)57 public int getPositionInContextNodeList(XPathContext xctxt) 58 { 59 60 // System.out.println("FuncPosition- entry"); 61 // If we're in a predicate, then this will return non-null. 62 SubContextList iter = m_isTopLevel ? null : xctxt.getSubContextList(); 63 64 if (null != iter) 65 { 66 int prox = iter.getProximityPosition(xctxt); 67 68 // System.out.println("FuncPosition- prox: "+prox); 69 return prox; 70 } 71 72 DTMIterator cnl = xctxt.getContextNodeList(); 73 74 if (null != cnl) 75 { 76 int n = cnl.getCurrentNode(); 77 if(n == DTM.NULL) 78 { 79 if(cnl.getCurrentPos() == 0) 80 return 0; 81 82 // Then I think we're in a sort. See sort21.xsl. So the iterator has 83 // already been spent, and is not on the node we're processing. 84 // It's highly possible that this is an issue for other context-list 85 // functions. Shouldn't be a problem for last(), and it shouldn't be 86 // a problem for current(). 87 try 88 { 89 cnl = cnl.cloneWithReset(); 90 } 91 catch(CloneNotSupportedException cnse) 92 { 93 throw new org.apache.xml.utils.WrappedRuntimeException(cnse); 94 } 95 int currentNode = xctxt.getContextNode(); 96 // System.out.println("currentNode: "+currentNode); 97 while(DTM.NULL != (n = cnl.nextNode())) 98 { 99 if(n == currentNode) 100 break; 101 } 102 } 103 // System.out.println("n: "+n); 104 // System.out.println("FuncPosition- cnl.getCurrentPos(): "+cnl.getCurrentPos()); 105 return cnl.getCurrentPos(); 106 } 107 108 // System.out.println("FuncPosition - out of guesses: -1"); 109 return -1; 110 } 111 112 /** 113 * Execute the function. The function must return 114 * a valid object. 115 * @param xctxt The current execution context. 116 * @return A valid XObject. 117 * 118 * @throws javax.xml.transform.TransformerException 119 */ execute(XPathContext xctxt)120 public XObject execute(XPathContext xctxt) throws javax.xml.transform.TransformerException 121 { 122 double pos = (double) getPositionInContextNodeList(xctxt); 123 124 return new XNumber(pos); 125 } 126 127 /** 128 * No arguments to process, so this does nothing. 129 */ fixupVariables(java.util.Vector vars, int globalsSize)130 public void fixupVariables(java.util.Vector vars, int globalsSize) 131 { 132 // no-op 133 } 134 } 135