FuncLang.java revision 9f8118474e9513f7a5b7d2a05e4a0fb15d1a6569 
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: FuncLang.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.xpath.XPathContext;
25import org.apache.xpath.objects.XBoolean;
26import org.apache.xpath.objects.XObject;
27
28/**
29 * Execute the Lang() function.
30 * @xsl.usage advanced
31 */
32public class FuncLang extends FunctionOneArg
33{
34    static final long serialVersionUID = -7868705139354872185L;
35
36  /**
37   * Execute the function.  The function must return
38   * a valid object.
39   * @param xctxt The current execution context.
40   * @return A valid XObject.
41   *
42   * @throws javax.xml.transform.TransformerException
43   */
44  public XObject execute(XPathContext xctxt) throws javax.xml.transform.TransformerException
45  {
46
47    String lang = m_arg0.execute(xctxt).str();
48    int parent = xctxt.getCurrentNode();
49    boolean isLang = false;
50    DTM dtm = xctxt.getDTM(parent);
51
52    while (DTM.NULL != parent)
53    {
54      if (DTM.ELEMENT_NODE == dtm.getNodeType(parent))
55      {
56        int langAttr = dtm.getAttributeNode(parent, "http://www.w3.org/XML/1998/namespace", "lang");
57
58        if (DTM.NULL != langAttr)
59        {
60          String langVal = dtm.getNodeValue(langAttr);
61          // %OPT%
62          if (langVal.toLowerCase().startsWith(lang.toLowerCase()))
63          {
64            int valLen = lang.length();
65
66            if ((langVal.length() == valLen)
67                    || (langVal.charAt(valLen) == '-'))
68            {
69              isLang = true;
70            }
71          }
72
73          break;
74        }
75      }
76
77      parent = dtm.getParent(parent);
78    }
79
80    return isLang ? XBoolean.S_TRUE : XBoolean.S_FALSE;
81  }
82}
83