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    1   /*
    2    * $Header: /home/projects/jaxen/scm/jaxen/src/java/main/org/jaxen/function/ext/LowerFunction.java,v 1.10 2005/06/28 13:44:45 elharo Exp $
    3    * $Revision: 1.10 $
    4    * $Date: 2005/06/28 13:44:45 $
    5    *
    6    * ====================================================================
    7    *
    8    * Copyright (C) 2000-2002 bob mcwhirter & James Strachan.
    9    * All rights reserved.
    10   *
    11   * Redistribution and use in source and binary forms, with or without
    12   * modification, are permitted provided that the following conditions
    13   * are met:
    14   *
    15   * 1. Redistributions of source code must retain the above copyright
    16   *    notice, this list of conditions, and the following disclaimer.
    17   *
    18   * 2. Redistributions in binary form must reproduce the above copyright
    19   *    notice, this list of conditions, and the disclaimer that follows
    20   *    these conditions in the documentation and/or other materials
    21   *    provided with the distribution.
    22   *
    23   * 3. The name "Jaxen" must not be used to endorse or promote products
    24   *    derived from this software without prior written permission.  For
    25   *    written permission, please contact license@jaxen.org.
    26   *
    27   * 4. Products derived from this software may not be called "Jaxen", nor
    28   *    may "Jaxen" appear in their name, without prior written permission
    29   *    from the Jaxen Project Management (pm@jaxen.org).
    30   *
    31   * In addition, we request (but do not require) that you include in the
    32   * end-user documentation provided with the redistribution and/or in the
    33   * software itself an acknowledgement equivalent to the following:
    34   *     "This product includes software developed by the
    35   *      Jaxen Project <http://www.jaxen.org/>."
    36   * Alternatively, the acknowledgment may be graphical using the logos
    37   * available at http://www.jaxen.org/
    38   *
    39   * THIS SOFTWARE IS PROVIDED ``AS IS'' AND ANY EXPRESSED OR IMPLIED
    40   * WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
    41   * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
    42   * DISCLAIMED.  IN NO EVENT SHALL THE Jaxen AUTHORS OR THE PROJECT
    43   * CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
    44   * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
    45   * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF
    46   * USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND
    47   * ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
    48   * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT
    49   * OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
    50   * SUCH DAMAGE.
    51   *
    52   * ====================================================================
    53   * This software consists of voluntary contributions made by many
    54   * individuals on behalf of the Jaxen Project and was originally
    55   * created by bob mcwhirter <bob@werken.com> and
    56   * James Strachan <jstrachan@apache.org>.  For more information on the
    57   * Jaxen Project, please see <http://www.jaxen.org/>.
    58   *
    59   * $Id: LowerFunction.java,v 1.10 2005/06/28 13:44:45 elharo Exp $
    60   */
    61
    62  package org.jaxen.function.ext;
    63
    64  import java.util.List;
    65  import java.util.Locale;
    66
    67  import org.jaxen.Context;
    68  import org.jaxen.FunctionCallException;
    69  import org.jaxen.Navigator;
    70  import org.jaxen.function.StringFunction;
    71
    72  /***
    73   * <p><code><i>string</i> lower-case(<i>string</i>)</code>
    74   *
    75   * This function can take a second parameter of the
    76   * <code>Locale</code> to use for the String conversion.
    77   * </p>
    78   *
    79   * <p>
    80   * For example
    81   *
    82   * <code>lower-case( /foo/bar )</code>
    83   * <code>lower-case( /foo/@name, $myLocale )</code>
    84   * </p>
    85   *
    86   * @author mark wilson (markw@wilsoncom.de)
    87   * @author <a href="mailto:jstrachan@apache.org">James Strachan</a>
    88   */
    89  public class LowerFunction extends LocaleFunctionSupport
    90  {
    91
    92      public Object call(Context context,
    93                         List args) throws FunctionCallException
    94      {
    95          Navigator navigator = context.getNavigator();
    96          int size = args.size();
    97          if (size > 0)
    98          {
    99              Object text = args.get(0);
    100             Locale locale = null;
    101             if (size > 1)
    102             {
    103                 locale = getLocale( args.get(1), navigator );
    104             }
    105             return evaluate( text, locale, navigator );
    106         }
    107         throw new FunctionCallException( "lower-case() requires at least one argument." );
    108     }
    109
    110     /***
    111      * Converts the given string value to lower case using an optional Locale
    112      *
    113      * @param strArg the value which gets converted to a String
    114      * @param locale the Locale to use for the conversion or null
    115      *        English should be used
    116      * @param nav the Navigator to use
    117      */
    118     public static String evaluate(Object strArg,
    119                                   Locale locale,
    120                                   Navigator nav)
    121     {
    122
    123         String str   = StringFunction.evaluate( strArg,
    124                                                 nav );
    125         // it might be possible to use the xml:lang attribute to
    126         // pick a default locale
    127         if (locale == null) locale = Locale.ENGLISH;
    128         return str.toLowerCase(locale);
    129
    130     }
    131 }