View Javadoc

1   /*
2    * $Header: /home/projects/jaxen/scm/jaxen/src/java/main/org/jaxen/function/ext/LowerFunction.java,v 1.9 2005/02/08 19:45:50 elharo Exp $
3    * $Revision: 1.9 $
4    * $Date: 2005/02/08 19:45:50 $
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 1.9 2005/02/08 19:45:50 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 }