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    */
execute(XPathContext xctxt)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