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: FuncGenerateId.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 GenerateId() function.
30  * @xsl.usage advanced
31  */
32 public class FuncGenerateId extends FunctionDef1Arg
33 {
34     static final long serialVersionUID = 973544842091724273L;
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 which = getArg0AsNode(xctxt);
48 
49     if (DTM.NULL != which)
50     {
51       // Note that this is a different value than in previous releases
52       // of Xalan. It's sensitive to the exact encoding of the node
53       // handle anyway, so fighting to maintain backward compatability
54       // really didn't make sense; it may change again as we continue
55       // to experiment with balancing document and node numbers within
56       // that value.
57       return new XString("N" + Integer.toHexString(which).toUpperCase());
58     }
59     else
60       return XString.EMPTYSTRING;
61   }
62 }
63