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1   package org.apache.turbine.services.localization;
2   
3   /*
4    * Copyright 2001-2005 The Apache Software Foundation.
5    *
6    * Licensed under the Apache License, Version 2.0 (the "License")
7    * you may not use this file except in compliance with the License.
8    * You may obtain a copy of the License at
9    *
10   *     http://www.apache.org/licenses/LICENSE-2.0
11   *
12   * Unless required by applicable law or agreed to in writing, software
13   * distributed under the License is distributed on an "AS IS" BASIS,
14   * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
15   * See the License for the specific language governing permissions and
16   * limitations under the License.
17   */
18  
19  import java.util.Locale;
20  import java.util.MissingResourceException;
21  import java.util.ResourceBundle;
22  
23  import org.apache.commons.logging.Log;
24  import org.apache.commons.logging.LogFactory;
25  import org.apache.turbine.services.pull.ApplicationTool;
26  import org.apache.turbine.util.RunData;
27  
28  /***
29   * A pull tool which provides lookups for localized text by delegating
30   * to the configured <code>LocalizationService</code>.
31   *
32   * @author <a href="mailto:dlr@collab.net">Daniel Rall</a>
33   * @author <a href="mailto:jon@collab.net">Jon Stevens</a>
34   * @version $Id: LocalizationTool.java 264148 2005-08-29 14:21:04Z henning $
35   */
36  public class LocalizationTool implements ApplicationTool
37  {
38      /*** Logging */
39      private static Log log = LogFactory.getLog(LocalizationTool.class);
40  
41      /***
42       * The language and country information parsed from the request's
43       * <code>Accept-Language</code> header.  Reset on each request.
44       */
45      protected Locale locale;
46  
47      /***
48       * The bundle for this request.
49       */
50      private ResourceBundle bundle;
51  
52      /***
53       * The name of the bundle for this tool to use.
54       */
55      private String bundleName;
56  
57      /***
58       * Creates a new instance.  Used by <code>PullService</code>.
59       */
60      public LocalizationTool()
61      {
62          refresh();
63      }
64  
65      /***
66       * <p>Performs text lookups for localization.</p>
67       *
68       * <p>Assuming there is a instance of this class with a HTTP
69       * request set in your template's context named <code>l10n</code>,
70       * the VTL <code>$l10n.HELLO</code> would render to
71       * <code>hello</code> for English requests and <code>hola</code>
72       * in Spanish (depending on the value of the HTTP request's
73       * <code>Accept-Language</code> header).</p>
74       *
75       * @param key The identifier for the localized text to retrieve.
76       * @return The localized text.
77       */
78      public String get(String key)
79      {
80          try
81          {
82              return Localization.getString(getBundleName(null), getLocale(), key);
83          }
84          catch (MissingResourceException noKey)
85          {
86              log.error(noKey);
87              return null;
88          }
89      }
90  
91      /***
92       * Gets the current locale.
93       *
94       * @return The locale currently in use.
95       */
96      public Locale getLocale()
97      {
98          return locale;
99      }
100 
101     /***
102      * The return value of this method is used to set the name of the
103      * bundle used by this tool.  Useful as a hook for using a
104      * different bundle than specifed in your
105      * <code>LocalizationService</code> configuration.
106      *
107      * @param data The inputs passed from {@link #init(Object)}.
108      * (ignored by this implementation).
109      */
110     protected String getBundleName(Object data)
111     {
112         return Localization.getDefaultBundleName();
113     }
114 
115 
116     // ApplicationTool implmentation
117 
118     /***
119      * Sets the request to get the <code>Accept-Language</code> header
120      * from (reset on each request).
121      */
122     public final void init(Object data)
123     {
124         if (data instanceof RunData)
125         {
126             // Pull necessary information out of RunData while we have
127             // a reference to it.
128             locale = Localization.getLocale(((RunData) data).getRequest());
129             bundleName = getBundleName(data);
130         }
131     }
132 
133     /***
134      * No-op.
135      */
136     public void refresh()
137     {
138         locale = null;
139         bundle = null;
140         bundleName = null;
141     }
142 }