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: FuncSum.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.xml.utils.XMLString;
26 import org.apache.xpath.XPathContext;
27 import org.apache.xpath.objects.XNumber;
28 import org.apache.xpath.objects.XObject;
29 
30 /**
31  * Execute the Sum() function.
32  * @xsl.usage advanced
33  */
34 public class FuncSum extends FunctionOneArg
35 {
36     static final long serialVersionUID = -2719049259574677519L;
37 
38   /**
39    * Execute the function.  The function must return
40    * a valid object.
41    * @param xctxt The current execution context.
42    * @return A valid XObject.
43    *
44    * @throws javax.xml.transform.TransformerException
45    */
execute(XPathContext xctxt)46   public XObject execute(XPathContext xctxt) throws javax.xml.transform.TransformerException
47   {
48 
49     DTMIterator nodes = m_arg0.asIterator(xctxt, xctxt.getCurrentNode());
50     double sum = 0.0;
51     int pos;
52 
53     while (DTM.NULL != (pos = nodes.nextNode()))
54     {
55       DTM dtm = nodes.getDTM(pos);
56       XMLString s = dtm.getStringValue(pos);
57 
58       if (null != s)
59         sum += s.toDouble();
60     }
61     nodes.detach();
62 
63     return new XNumber(sum);
64   }
65 }
66