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: FuncLast.java 468655 2006-10-28 07:12:06Z minchau $
20  */
21 package org.apache.xpath.functions;
22 
23 import org.apache.xml.dtm.DTMIterator;
24 import org.apache.xpath.XPathContext;
25 import org.apache.xpath.axes.SubContextList;
26 import org.apache.xpath.compiler.Compiler;
27 import org.apache.xpath.objects.XNumber;
28 import org.apache.xpath.objects.XObject;
29 
30 
31 /**
32  * Execute the Last() function.
33  * @xsl.usage advanced
34  */
35 public class FuncLast extends Function
36 {
37     static final long serialVersionUID = 9205812403085432943L;
38 
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    */
postCompileStep(Compiler compiler)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 non-null reference to XPath runtime context.
54    *
55    * @return The number of nodes in the list.
56    *
57    * @throws javax.xml.transform.TransformerException
58    */
getCountOfContextNodeList(XPathContext xctxt)59   public int getCountOfContextNodeList(XPathContext xctxt)
60           throws javax.xml.transform.TransformerException
61   {
62 
63     // assert(null != m_contextNodeList, "m_contextNodeList must be non-null");
64     // If we're in a predicate, then this will return non-null.
65     SubContextList iter = m_isTopLevel ? null : xctxt.getSubContextList();
66 
67     // System.out.println("iter: "+iter);
68     if (null != iter)
69       return iter.getLastPos(xctxt);
70 
71     DTMIterator cnl = xctxt.getContextNodeList();
72     int count;
73     if(null != cnl)
74     {
75       count = cnl.getLength();
76       // System.out.println("count: "+count);
77     }
78     else
79       count = 0;
80     return count;
81   }
82 
83   /**
84    * Execute the function.  The function must return
85    * a valid object.
86    * @param xctxt The current execution context.
87    * @return A valid XObject.
88    *
89    * @throws javax.xml.transform.TransformerException
90    */
execute(XPathContext xctxt)91   public XObject execute(XPathContext xctxt) throws javax.xml.transform.TransformerException
92   {
93     XNumber xnum = new XNumber((double) getCountOfContextNodeList(xctxt));
94     // System.out.println("last: "+xnum.num());
95     return xnum;
96   }
97 
98   /**
99    * No arguments to process, so this does nothing.
100    */
fixupVariables(java.util.Vector vars, int globalsSize)101   public void fixupVariables(java.util.Vector vars, int globalsSize)
102   {
103     // no-op
104   }
105 
106 }
107