001    /*
002     * Licensed to the Apache Software Foundation (ASF) under one
003     * or more contributor license agreements. See the NOTICE file
004     * distributed with this work for additional information
005     * regarding copyright ownership. The ASF licenses this file
006     * to you under the Apache License, Version 2.0 (the  "License");
007     * you may not use this file except in compliance with the License.
008     * You may obtain a copy of the License at
009     *
010     *     http://www.apache.org/licenses/LICENSE-2.0
011     *
012     * Unless required by applicable law or agreed to in writing, software
013     * distributed under the License is distributed on an "AS IS" BASIS,
014     * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
015     * See the License for the specific language governing permissions and
016     * limitations under the License.
017     */
018    /*
019     * $Id: FuncCurrent.java 468655 2006-10-28 07:12:06Z minchau $
020     */
021    package org.apache.xpath.functions;
022    
023    import org.apache.xml.dtm.DTM;
024    import org.apache.xml.dtm.DTMIterator;
025    import org.apache.xpath.XPathContext;
026    import org.apache.xpath.axes.LocPathIterator;
027    import org.apache.xpath.axes.PredicatedNodeTest;
028    import org.apache.xpath.objects.XNodeSet;
029    import org.apache.xpath.objects.XObject;
030    import org.apache.xpath.axes.SubContextList;
031    import org.apache.xpath.patterns.StepPattern;
032    import org.apache.xalan.res.XSLMessages;
033    import org.apache.xalan.res.XSLTErrorResources;
034    
035    
036    /**
037     * Execute the current() function.
038     * @xsl.usage advanced
039     */
040    public class FuncCurrent extends Function
041    {
042        static final long serialVersionUID = 5715316804877715008L;
043    
044      /**
045       * Execute the function.  The function must return
046       * a valid object.
047       * @param xctxt The current execution context.
048       * @return A valid XObject.
049       *
050       * @throws javax.xml.transform.TransformerException
051       */
052      public XObject execute(XPathContext xctxt) throws javax.xml.transform.TransformerException
053      {
054       
055        SubContextList subContextList = xctxt.getCurrentNodeList();
056        int currentNode = DTM.NULL;
057    
058        if (null != subContextList) {
059            if (subContextList instanceof PredicatedNodeTest) {
060                LocPathIterator iter = ((PredicatedNodeTest)subContextList)
061                                                              .getLocPathIterator();
062                currentNode = iter.getCurrentContextNode();
063             } else if(subContextList instanceof StepPattern) {
064               throw new RuntimeException(XSLMessages.createMessage(
065                  XSLTErrorResources.ER_PROCESSOR_ERROR,null));
066             }
067        } else {
068            // not predicate => ContextNode == CurrentNode
069            currentNode = xctxt.getContextNode();
070        }
071        return new XNodeSet(currentNode, xctxt.getDTMManager());
072      }
073      
074      /**
075       * No arguments to process, so this does nothing.
076       */
077      public void fixupVariables(java.util.Vector vars, int globalsSize)
078      {
079        // no-op
080      }
081    
082    }