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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: FuncNamespace.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.XObject;
     26 import org.apache.xpath.objects.XString;
     27 
     28 /**
     29  * Execute the Namespace() function.
     30  * @xsl.usage advanced
     31  */
     32 public class FuncNamespace extends FunctionDef1Arg
     33 {
     34     static final long serialVersionUID = -4695674566722321237L;
     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     int context = getArg0AsNode(xctxt);
     48 
     49     String s;
     50     if(context != DTM.NULL)
     51     {
     52       DTM dtm = xctxt.getDTM(context);
     53       int t = dtm.getNodeType(context);
     54       if(t == DTM.ELEMENT_NODE)
     55       {
     56         s = dtm.getNamespaceURI(context);
     57       }
     58       else if(t == DTM.ATTRIBUTE_NODE)
     59       {
     60 
     61         // This function always returns an empty string for namespace nodes.
     62         // We check for those here.  Fix inspired by Davanum Srinivas.
     63 
     64         s = dtm.getNodeName(context);
     65         if(s.startsWith("xmlns:") || s.equals("xmlns"))
     66           return XString.EMPTYSTRING;
     67 
     68         s = dtm.getNamespaceURI(context);
     69       }
     70       else
     71         return XString.EMPTYSTRING;
     72     }
     73     else
     74       return XString.EMPTYSTRING;
     75 
     76     return ((null == s) ? XString.EMPTYSTRING : new XString(s));
     77   }
     78 }
     79