src/org/apache/xpath/functions/FuncNodeKind.java

/*
 * The Apache Software License, Version 1.1
 *
 *
 * Copyright (c) 1999-2003 The Apache Software Foundation.  All rights 
 * reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 *
 * 1. Redistributions of source code must retain the above copyright
 *    notice, this list of conditions and the following disclaimer. 
 *
 * 2. Redistributions in binary form must reproduce the above copyright
 *    notice, this list of conditions and the following disclaimer in
 *    the documentation and/or other materials provided with the
 *    distribution.
 *
 * 3. The end-user documentation included with the redistribution,
 *    if any, must include the following acknowledgment:  
 *       "This product includes software developed by the
 *        Apache Software Foundation (http://www.apache.org/)."
 *    Alternately, this acknowledgment may appear in the software itself,
 *    if and wherever such third-party acknowledgments normally appear.
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 * 4. The names "Xalan" and "Apache Software Foundation" must
 *    not be used to endorse or promote products derived from this
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 * 5. Products derived from this software may not be called "Apache",
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 *
 * THIS SOFTWARE IS PROVIDED ``AS IS'' AND ANY EXPRESSED OR IMPLIED
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 * ITS CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
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 * ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
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 * OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
 * SUCH DAMAGE.
 * ====================================================================
 *
 * This software consists of voluntary contributions made by many
 * individuals on behalf of the Apache Software Foundation and was
 * originally based on software copyright (c) 1999, Lotus
 * Development Corporation., http://www.lotus.com.  For more
 * information on the Apache Software Foundation, please see
 * <http://www.apache.org/>.
 */
package org.apache.xpath.functions;

import org.apache.xpath.res.XPATHErrorResources;

//import org.w3c.dom.Node;
//import org.w3c.dom.traversal.NodeIterator;
import org.apache.xml.dtm.DTM;
import org.apache.xml.dtm.DTMIterator;

import java.util.Vector;

import org.apache.xpath.XPathContext;
import org.apache.xpath.XPath;
import org.apache.xpath.objects.XObject;
import org.apache.xpath.objects.XString;
import org.apache.xpath.objects.XSequence;

/**
 * <meta name="usage" content="advanced"/>
 * Execute the xf:node-kind function, returning a string. 
 * 
 * %OPT% Would it be better to create a single stored instance of
 * each of the possible XStrings? More resources burned during 
 * initialization, fewer during execution... but this is a rarely
 * used function.
 * 
 * @author Joe Kesselman
 * @since Aug 27, 2002
 */
public class FuncNodeKind extends FunctionDef1Arg
{
  /**
   * Execute the function.  The function must return
   * a valid object.
   * @param xctxt The current execution context.
   * @return An XString containing the node kind name, or
   * XObject.EMPTY if the input wasn't one of the acceptable values.
   *
   * @throws javax.xml.transform.TransformerException
   */
  public XObject execute(XPathContext xctxt) throws javax.xml.transform.TransformerException
  {
    int context = getArg0AsNode(xctxt);
    String s=null;
    
    if(DTM.NULL != context)
    {
	    DTM dtm = xctxt.getDTM(context);
    	switch (dtm.getNodeType(context))
	    {
    		case DTM.ATTRIBUTE_NODE:
    			s="attribute";
    			break;
	    	case DTM.DOCUMENT_NODE:
    			s="document";
    			break;
	    	case DTM.COMMENT_NODE:
    			s="comment";
    			break;
    		case DTM.ELEMENT_NODE:
    			s="element";
    			break;
    		case DTM.NAMESPACE_NODE:
    			s="namespace";
				break;
    		case DTM.PROCESSING_INSTRUCTION_NODE:
    			s="processing-instruction";
    			break;
    		case DTM.TEXT_NODE:
    			s="text";
    			break;
    		default:
    			// leave it unknown? SHOULD NOT ARISE!
    			break;
	    }
    }

	// s *should* never be left as null, since we shouldn't be called
	// unless the parameter is a Node. But it's unclear whether we
	// should throw a runtime exception or return something else
	// in that case.
	if(s==null)
		return XSequence.EMPTY; 
	else		
		return new XString(s);
  }
}