1 /*

     2  * reserved comment block

     3  * DO NOT REMOVE OR ALTER!

     4  */

     5 /*

     6  * Licensed to the Apache Software Foundation (ASF) under one or more

     7  * contributor license agreements.  See the NOTICE file distributed with

     8  * this work for additional information regarding copyright ownership.

     9  * The ASF licenses this file to You under the Apache License, Version 2.0

    10  * (the "License"); you may not use this file except in compliance with

    11  * the License.  You may obtain a copy of the License at

    12  *

    13  *      http://www.apache.org/licenses/LICENSE-2.0

    14  *

    15  * Unless required by applicable law or agreed to in writing, software

    16  * distributed under the License is distributed on an "AS IS" BASIS,

    17  * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.

    18  * See the License for the specific language governing permissions and

    19  * limitations under the License.

    20  */

    21 

    22 package com.sun.org.apache.xpath.internal.functions;

    23 

    24 import com.sun.org.apache.xml.internal.dtm.DTM;

    25 import com.sun.org.apache.xml.internal.dtm.DTMIterator;

    26 import com.sun.org.apache.xpath.internal.XPathContext;

    27 import com.sun.org.apache.xpath.internal.axes.SubContextList;

    28 import com.sun.org.apache.xpath.internal.compiler.Compiler;

    29 import com.sun.org.apache.xpath.internal.objects.XNumber;

    30 import com.sun.org.apache.xpath.internal.objects.XObject;

    31 

    32 /**

    33  * Execute the Position() function.

    34  * @xsl.usage advanced

    35  */

    36 public class FuncPosition extends Function

    37 {

    38     static final long serialVersionUID = -9092846348197271582L;

    39   private boolean m_isTopLevel;

    40 

    41   /**

    42    * Figure out if we're executing a toplevel expression.

    43    * If so, we can't be inside of a predicate.

    44    */

    45   public void postCompileStep(Compiler compiler)

    46   {

    47     m_isTopLevel = compiler.getLocationPathDepth() == -1;

    48   }

    49 

    50   /**

    51    * Get the position in the current context node list.

    52    *

    53    * @param xctxt Runtime XPath context.

    54    *

    55    * @return The current position of the itteration in the context node list,

    56    *         or -1 if there is no active context node list.

    57    */

    58   public int getPositionInContextNodeList(XPathContext xctxt)

    59   {

    60 

    61     // System.out.println("FuncPosition- entry");

    62     // If we're in a predicate, then this will return non-null.

    63     SubContextList iter = m_isTopLevel ? null : xctxt.getSubContextList();

    64 

    65     if (null != iter)

    66     {

    67       int prox = iter.getProximityPosition(xctxt);

    68 

    69       // System.out.println("FuncPosition- prox: "+prox);

    70       return prox;

    71     }

    72 

    73     DTMIterator cnl = xctxt.getContextNodeList();

    74 

    75     if (null != cnl)

    76     {

    77       int n = cnl.getCurrentNode();

    78       if(n == DTM.NULL)

    79       {

    80         if(cnl.getCurrentPos() == 0)

    81           return 0;

    82 

    83         // Then I think we're in a sort.  See sort21.xsl. So the iterator has

    84         // already been spent, and is not on the node we're processing.

    85         // It's highly possible that this is an issue for other context-list

    86         // functions.  Shouldn't be a problem for last(), and it shouldn't be

    87         // a problem for current().

    88         try

    89         {

    90           cnl = cnl.cloneWithReset();

    91         }

    92         catch(CloneNotSupportedException cnse)

    93         {

    94           throw new com.sun.org.apache.xml.internal.utils.WrappedRuntimeException(cnse);

    95         }

    96         int currentNode = xctxt.getContextNode();

    97         // System.out.println("currentNode: "+currentNode);

    98         while(DTM.NULL != (n = cnl.nextNode()))

    99         {

   100           if(n == currentNode)

   101             break;

   102         }

   103       }

   104       // System.out.println("n: "+n);

   105       // System.out.println("FuncPosition- cnl.getCurrentPos(): "+cnl.getCurrentPos());

   106       return cnl.getCurrentPos();

   107     }

   108 

   109     // System.out.println("FuncPosition - out of guesses: -1");

   110     return -1;

   111   }

   112 

   113   /**

   114    * Execute the function.  The function must return

   115    * a valid object.

   116    * @param xctxt The current execution context.

   117    * @return A valid XObject.

   118    *

   119    * @throws javax.xml.transform.TransformerException

   120    */

   121   public XObject execute(XPathContext xctxt) throws javax.xml.transform.TransformerException

   122   {

   123     double pos = (double) getPositionInContextNodeList(xctxt);

   124 

   125     return new XNumber(pos);

   126   }

   127 

   128   /**

   129    * No arguments to process, so this does nothing.

   130    */

   131   public void fixupVariables(java.util.Vector vars, int globalsSize)

   132   {

   133     // no-op

   134   }

   135 }