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      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    */
     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