001 /*
002 * Licensed to the Apache Software Foundation (ASF) under one
003 * or more contributor license agreements. See the NOTICE file
004 * distributed with this work for additional information
005 * regarding copyright ownership. The ASF licenses this file
006 * to you under the Apache License, Version 2.0 (the "License");
007 * you may not use this file except in compliance with the License.
008 * You may obtain a copy of the License at
009 *
010 * http://www.apache.org/licenses/LICENSE-2.0
011 *
012 * Unless required by applicable law or agreed to in writing, software
013 * distributed under the License is distributed on an "AS IS" BASIS,
014 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
015 * See the License for the specific language governing permissions and
016 * limitations under the License.
017 */
018 /*
019 * $Id: FuncExtElementAvailable.java 468655 2006-10-28 07:12:06Z minchau $
020 */
021 package org.apache.xpath.functions;
022
023 import org.apache.xalan.templates.Constants;
024 import org.apache.xalan.transformer.TransformerImpl;
025 import org.apache.xml.utils.QName;
026 import org.apache.xpath.ExtensionsProvider;
027 import org.apache.xpath.XPathContext;
028 import org.apache.xpath.objects.XBoolean;
029 import org.apache.xpath.objects.XObject;
030
031 /**
032 * Execute the ExtElementAvailable() function.
033 * @xsl.usage advanced
034 */
035 public class FuncExtElementAvailable extends FunctionOneArg
036 {
037 static final long serialVersionUID = -472533699257968546L;
038
039 /**
040 * Execute the function. The function must return
041 * a valid object.
042 * @param xctxt The current execution context.
043 * @return A valid XObject.
044 *
045 * @throws javax.xml.transform.TransformerException
046 */
047 public XObject execute(XPathContext xctxt) throws javax.xml.transform.TransformerException
048 {
049
050 String prefix;
051 String namespace;
052 String methName;
053
054 String fullName = m_arg0.execute(xctxt).str();
055 int indexOfNSSep = fullName.indexOf(':');
056
057 if (indexOfNSSep < 0)
058 {
059 prefix = "";
060 namespace = Constants.S_XSLNAMESPACEURL;
061 methName = fullName;
062 }
063 else
064 {
065 prefix = fullName.substring(0, indexOfNSSep);
066 namespace = xctxt.getNamespaceContext().getNamespaceForPrefix(prefix);
067 if (null == namespace)
068 return XBoolean.S_FALSE;
069 methName= fullName.substring(indexOfNSSep + 1);
070 }
071
072 if (namespace.equals(Constants.S_XSLNAMESPACEURL)
073 || namespace.equals(Constants.S_BUILTIN_EXTENSIONS_URL))
074 {
075 try
076 {
077 TransformerImpl transformer = (TransformerImpl) xctxt.getOwnerObject();
078 return transformer.getStylesheet().getAvailableElements().containsKey(
079 new QName(namespace, methName))
080 ? XBoolean.S_TRUE : XBoolean.S_FALSE;
081 }
082 catch (Exception e)
083 {
084 return XBoolean.S_FALSE;
085 }
086 }
087 else
088 {
089 //dml
090 ExtensionsProvider extProvider = (ExtensionsProvider)xctxt.getOwnerObject();
091 return extProvider.elementAvailable(namespace, methName)
092 ? XBoolean.S_TRUE : XBoolean.S_FALSE;
093 }
094 }
095 }