/*
* $Header: /home/projects/jaxen/scm/jaxen/src/java/main/org/jaxen/function/ConcatFunction.java,v 1.9 2006/02/05 21:47:41 elharo Exp $
* $Revision: 1.9 $
* $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: ConcatFunction.java,v 1.9 2006/02/05 21:47:41 elharo Exp $
*/
package org.orbeon.jaxen.function;
import org.orbeon.jaxen.Context;
import org.orbeon.jaxen.Function;
import org.orbeon.jaxen.FunctionCallException;
import org.orbeon.jaxen.Navigator;
import java.util.Iterator;
import java.util.List;
/**
* <b>4.2</b> <code><i>string</i> concat(<i>string</i>,<i>string</i>,<i>string*</i>)</code>
* <p>
* Concatenates its arguments and returns the resulting string.
* </p>
*
* @author bob mcwhirter (bob@werken.com)
*
* @see <a href="http://www.w3.org/TR/xpath#function-concat">Section 4.2 of the XPath Specification</a>
*/
public class ConcatFunction implements Function
{
/**
* Create a new <code>ConcatFunction</code> object.
*/
public ConcatFunction() {}
/**
* Concatenates the arguments and returns the resulting string.
* Non-string items are first converted to strings as if by the
* XPath <code>string()<code> function.
*
* @param context the context at the point in the
* expression when the function is called
* @param args the list of strings to be concatenated
*
* @return a <code>String</code> containing the concatenation of the items
* of <code>args</code>
*
* @throws FunctionCallException if <code>args</code> has less than two items
*/
public Object call(Context context,
List args) throws FunctionCallException
{
if ( args.size() >= 2 )
{
return evaluate( args,
context.getNavigator() );
}
throw new FunctionCallException("concat() requires at least two arguments");
}
/**
* Converts each item in the list to a string and returns the
* concatenation of these strings.
* If necessary, each item is first converted to a <code>String</code>
* as if by the XPath <code>string()</code> function.
*
* @param list the items to be concatenated
* @param nav ignored
*
* @return the concatenation of the arguments
*/
public static String evaluate(List list,
Navigator nav)
{
StringBuffer result = new StringBuffer();
Iterator argIter = list.iterator();
while ( argIter.hasNext() )
{
result.append( StringFunction.evaluate( argIter.next(),
nav ) );
}
return result.toString();
}
}