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 */
21package org.apache.xpath.functions;
22
23import org.apache.xml.dtm.DTM;
24import org.apache.xml.dtm.DTMIterator;
25import org.apache.xml.utils.XMLString;
26import org.apache.xpath.XPathContext;
27import org.apache.xpath.objects.XNumber;
28import org.apache.xpath.objects.XObject;
29
30/**
31 * Execute the Sum() function.
32 * @xsl.usage advanced
33 */
34public 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   */
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