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  */
21 package org.apache.xpath.functions;
22 
23 import org.apache.xml.dtm.DTM;
24 import org.apache.xpath.XPathContext;
25 import org.apache.xpath.objects.XBoolean;
26 import org.apache.xpath.objects.XObject;
27 
28 /**
29  * Execute the Lang() function.
30  * @xsl.usage advanced
31  */
32 public 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    */
execute(XPathContext xctxt)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