content: /*
   * $Header$
   * $Revision$
   * $Date$
   *
   * ====================================================================
   *
   * 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/>.
   * 
   * $Id$
   */
  
  package org.jaxen.function.ext;
  
  import java.util.List;
  import java.util.Locale;
  
  import org.jaxen.Context;
  import org.jaxen.FunctionCallException;
  import org.jaxen.Navigator;
  import org.jaxen.function.StringFunction;
  
  /**
   * <p><code><i>string</i> lower-case(<i>string</i>)</code>
   *
   * This function can take a second parameter of the 
   * <code>Locale</code> to use for the String conversion.
   * </p>
   *
   * <p>
   * For example
   *
   * <code>lower-case( /foo/bar )</code>
   * <code>lower-case( /foo/@name, $myLocale )</code>
   * </p>
   *
   * @author mark wilson (markw@wilsoncom.de)
   * @author <a href="mailto:jstrachan@apache.org">James Strachan</a>
   */
  public class LowerFunction extends LocaleFunctionSupport
  {
  
      public Object call(Context context,
                         List args) throws FunctionCallException
      {
          Navigator navigator = context.getNavigator();
          int size = args.size();
          if (size > 0)
          {
              Object text = args.get(0);
              Locale locale = null;
              if (size > 1)
              {  
                  locale = getLocale( args.get(1), navigator );
              }
              return evaluate( text, locale, navigator );
          }
          throw new FunctionCallException( "lower-case() requires at least one argument." );
      }
  
      /**
       * Converts the given string value to lower case using an optional Locale
       * 
       * @param strArg the value which gets converted to a String
       * @param locale the Locale to use for the conversion or null
       *        English should be used
       * @param nav the Navigator to use
       */
      public static String evaluate(Object strArg,
                                    Locale locale,
                                    Navigator nav)
      {
  
          String str   = StringFunction.evaluate( strArg,
                                                  nav );
          // it might be possible to use the xml:lang attribute to
          // pick a default locale
          if (locale == null) locale = Locale.ENGLISH;
          return str.toLowerCase(locale);
          
      }
  }
  