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      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: FuncCurrent.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.LocPathIterator;
     27 import org.apache.xpath.axes.PredicatedNodeTest;
     28 import org.apache.xpath.objects.XNodeSet;
     29 import org.apache.xpath.objects.XObject;
     30 import org.apache.xpath.axes.SubContextList;
     31 import org.apache.xpath.patterns.StepPattern;
     32 import org.apache.xalan.res.XSLMessages;
     33 import org.apache.xalan.res.XSLTErrorResources;
     34 
     35 
     36 /**
     37  * Execute the current() function.
     38  * @xsl.usage advanced
     39  */
     40 public class FuncCurrent extends Function
     41 {
     42     static final long serialVersionUID = 5715316804877715008L;
     43 
     44   /**
     45    * Execute the function.  The function must return
     46    * a valid object.
     47    * @param xctxt The current execution context.
     48    * @return A valid XObject.
     49    *
     50    * @throws javax.xml.transform.TransformerException
     51    */
     52   public XObject execute(XPathContext xctxt) throws javax.xml.transform.TransformerException
     53   {
     54 
     55     SubContextList subContextList = xctxt.getCurrentNodeList();
     56     int currentNode = DTM.NULL;
     57 
     58     if (null != subContextList) {
     59         if (subContextList instanceof PredicatedNodeTest) {
     60             LocPathIterator iter = ((PredicatedNodeTest)subContextList)
     61                                                           .getLocPathIterator();
     62             currentNode = iter.getCurrentContextNode();
     63          } else if(subContextList instanceof StepPattern) {
     64            throw new RuntimeException(XSLMessages.createMessage(
     65               XSLTErrorResources.ER_PROCESSOR_ERROR,null));
     66          }
     67     } else {
     68         // not predicate => ContextNode == CurrentNode
     69         currentNode = xctxt.getContextNode();
     70     }
     71     return new XNodeSet(currentNode, xctxt.getDTMManager());
     72   }
     73 
     74   /**
     75    * No arguments to process, so this does nothing.
     76    */
     77   public void fixupVariables(java.util.Vector vars, int globalsSize)
     78   {
     79     // no-op
     80   }
     81 
     82 }
     83