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Java > Open Source Codes > com > sun > org > apache > xpath > internal > functions > FuncExtFunctionAvailable


1 /*
2  * Copyright 1999-2004 The Apache Software Foundation.
3  *
4  * Licensed under the Apache License, Version 2.0 (the "License");
5  * you may not use this file except in compliance with the License.
6  * You may obtain a copy of the License at
7  *
8  * http://www.apache.org/licenses/LICENSE-2.0
9  *
10  * Unless required by applicable law or agreed to in writing, software
11  * distributed under the License is distributed on an "AS IS" BASIS,
12  * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
13  * See the License for the specific language governing permissions and
14  * limitations under the License.
15  */
16 /*
17  * $Id: FuncExtFunctionAvailable.java,v 1.11 2004/02/17 04:34:00 minchau Exp $
18  */
19 package com.sun.org.apache.xpath.internal.functions;
20
21 import com.sun.org.apache.xalan.internal.templates.Constants;
22 import com.sun.org.apache.xpath.internal.ExtensionsProvider;
23 import com.sun.org.apache.xpath.internal.XPathContext;
24 import com.sun.org.apache.xpath.internal.compiler.Keywords;
25 import com.sun.org.apache.xpath.internal.objects.XBoolean;
26 import com.sun.org.apache.xpath.internal.objects.XObject;
27
28 /**
29  * Execute the ExtFunctionAvailable() function.
30  * @xsl.usage advanced
31  */
32 public class FuncExtFunctionAvailable extends FunctionOneArg
33 {
34
35   /**
36    * Execute the function. The function must return
37    * a valid object.
38    * @param xctxt The current execution context.
39    * @return A valid XObject.
40    *
41    * @throws javax.xml.transform.TransformerException
42    */
43   public XObject execute(XPathContext xctxt) throws javax.xml.transform.TransformerException JavaDoc
44   {
45
46     String JavaDoc prefix;
47     String JavaDoc namespace;
48     String JavaDoc methName;
49
50     String JavaDoc fullName = m_arg0.execute(xctxt).str();
51     int indexOfNSSep = fullName.indexOf(':');
52
53     if (indexOfNSSep < 0)
54     {
55       prefix = "";
56       namespace = Constants.S_XSLNAMESPACEURL;
57       methName = fullName;
58     }
59     else
60     {
61       prefix = fullName.substring(0, indexOfNSSep);
62       namespace = xctxt.getNamespaceContext().getNamespaceForPrefix(prefix);
63       if (null == namespace)
64         return XBoolean.S_FALSE;
65         methName = fullName.substring(indexOfNSSep + 1);
66     }
67
68     if (namespace.equals(Constants.S_XSLNAMESPACEURL))
69     {
70       try
71       {
72         return Keywords.functionAvailable(methName) ? XBoolean.S_TRUE : XBoolean.S_FALSE;
73       }
74       catch (Exception JavaDoc e)
75       {
76         return XBoolean.S_FALSE;
77       }
78     }
79     else
80     {
81       //dml
82 ExtensionsProvider extProvider = (ExtensionsProvider)xctxt.getOwnerObject();
83       return extProvider.functionAvailable(namespace, methName)
84              ? XBoolean.S_TRUE : XBoolean.S_FALSE;
85     }
86   }
87 }
88
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