/*
* $Header: /home/projects/jaxen/scm/jaxen/src/java/main/org/jaxen/function/LocalNameFunction.java,v 1.14 2006/02/05 21:47:41 elharo Exp $
* $Revision: 1.14 $
* $Date: 2006/02/05 21:47:41 $
*
* ====================================================================
*
* Copyright 2000-2002 bob mcwhirter & James Strachan.
* All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions are
* met:
*
* * Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
*
* * 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.
*
* * Neither the name of the Jaxen Project nor the names of its
* contributors may be used to endorse or promote products derived
* from this software without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS
* IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
* TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A
* PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER
* OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
* EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
* PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR
* PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF
* LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING
* NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT 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 Jaxen Project and was originally
* created by bob mcwhirter <bob@werken.com> and
* James Strachan <jstrachan@apache.org>. For more information on the
* Jaxen Project, please see <http://www.jaxen.org/>.
*
* $Id: LocalNameFunction.java,v 1.14 2006/02/05 21:47:41 elharo Exp $
*/
package org.jaxen.function;
import java.util.List;
import org.jaxen.Context;
import org.jaxen.Function;
import org.jaxen.FunctionCallException;
import org.jaxen.Navigator;
/**
* <p><b>4.1</b> <code><i>string</i> local-name(<i>node-set?</i>)</code></p>
*
*
* <blockquote src="http://www.w3.org/TR/xpath">
* The <b>local-name</b> function returns the local part of the
* expanded-name of the node in the argument node-set that is first in document order.
* If the argument node-set is empty or the first node has no expanded-name, an
* empty string is returned. If the argument is omitted, it defaults to a node-set with the context node as its only member.
*
* </blockquote>
*
* @author bob mcwhirter (bob @ werken.com)
* @see <a href="http://www.w3.org/TR/xpath#function-local-name" target="_top">Section 4.1 of the XPath Specification</a>
*/
public class LocalNameFunction implements Function
{
/**
* Create a new <code>LocalNameFunction</code> object.
*/
public LocalNameFunction() {}
/**
* Returns the local-name of the specified node or the context node if
* no arguments are provided.
*
* @param context the context at the point in the
* expression where the function is called
* @param args a <code>List</code> containing zero or one items
*
* @return a <code>String</code> containing the local-name
*
* @throws FunctionCallException if <code>args</code> has more than one item
*/
public Object call(Context context,
List args) throws FunctionCallException
{
if ( args.size() == 0 )
{
return evaluate( context.getNodeSet(),
context.getNavigator() );
}
if ( args.size() == 1 )
{
return evaluate( args,
context.getNavigator() );
}
throw new FunctionCallException( "local-name() requires zero or one argument." );
}
/**
* Returns the local-name of <code>list.get(0)</code>
*
* @param list a list of nodes
* @param nav the <code>Navigator</code> used to retrieve the local name
*
* @return the local-name of <code>list.get(0)</code>
*
* @throws FunctionCallException if <code>list.get(0)</code> is not a node
*/
public static String evaluate(List list,
Navigator nav) throws FunctionCallException
{
if ( ! list.isEmpty() )
{
Object first = list.get(0);
if (first instanceof List)
{
return evaluate( (List) first,
nav );
}
else if ( nav.isElement( first ) )
{
return nav.getElementName( first );
}
else if ( nav.isAttribute( first ) )
{
return nav.getAttributeName( first );
}
else if ( nav.isProcessingInstruction( first ) )
{
return nav.getProcessingInstructionTarget( first );
}
else if ( nav.isNamespace( first ) )
{
return nav.getNamespacePrefix( first );
}
else if ( nav.isDocument( first ) )
{
return "";
}
else if ( nav.isComment( first ) )
{
return "";
}
else if ( nav.isText( first ) )
{
return "";
}
else {
throw new FunctionCallException("The argument to the local-name function must be a node-set");
}
}
return "";
}
}