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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: FuncExtElementAvailable.java 468655 2006-10-28 07:12:06Z minchau $
     20  */
     21 package org.apache.xpath.functions;
     22 
     23 import org.apache.xalan.templates.Constants;
     24 import org.apache.xalan.transformer.TransformerImpl;
     25 import org.apache.xml.utils.QName;
     26 import org.apache.xpath.ExtensionsProvider;
     27 import org.apache.xpath.XPathContext;
     28 import org.apache.xpath.objects.XBoolean;
     29 import org.apache.xpath.objects.XObject;
     30 
     31 /**
     32  * Execute the ExtElementAvailable() function.
     33  * @xsl.usage advanced
     34  */
     35 public class FuncExtElementAvailable extends FunctionOneArg
     36 {
     37     static final long serialVersionUID = -472533699257968546L;
     38 
     39   /**
     40    * Execute the function.  The function must return
     41    * a valid object.
     42    * @param xctxt The current execution context.
     43    * @return A valid XObject.
     44    *
     45    * @throws javax.xml.transform.TransformerException
     46    */
     47   public XObject execute(XPathContext xctxt) throws javax.xml.transform.TransformerException
     48   {
     49 
     50     String prefix;
     51     String namespace;
     52     String methName;
     53 
     54     String fullName = m_arg0.execute(xctxt).str();
     55     int indexOfNSSep = fullName.indexOf(':');
     56 
     57     if (indexOfNSSep < 0)
     58     {
     59       prefix = "";
     60       namespace = Constants.S_XSLNAMESPACEURL;
     61       methName = fullName;
     62     }
     63     else
     64     {
     65       prefix = fullName.substring(0, indexOfNSSep);
     66       namespace = xctxt.getNamespaceContext().getNamespaceForPrefix(prefix);
     67       if (null == namespace)
     68         return XBoolean.S_FALSE;
     69       methName= fullName.substring(indexOfNSSep + 1);
     70     }
     71 
     72     if (namespace.equals(Constants.S_XSLNAMESPACEURL)
     73     ||  namespace.equals(Constants.S_BUILTIN_EXTENSIONS_URL))
     74     {
     75       try
     76       {
     77         TransformerImpl transformer = (TransformerImpl) xctxt.getOwnerObject();
     78         return transformer.getStylesheet().getAvailableElements().containsKey(
     79                                                             new QName(namespace, methName))
     80                ? XBoolean.S_TRUE : XBoolean.S_FALSE;
     81       }
     82       catch (Exception e)
     83       {
     84         return XBoolean.S_FALSE;
     85       }
     86     }
     87     else
     88     {
     89       //dml
     90       ExtensionsProvider extProvider = (ExtensionsProvider)xctxt.getOwnerObject();
     91       return extProvider.elementAvailable(namespace, methName)
     92              ? XBoolean.S_TRUE : XBoolean.S_FALSE;
     93     }
     94   }
     95 }
     96