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1   package org.apache.turbine.services.localization;
2   
3   /*
4    * Licensed to the Apache Software Foundation (ASF) under one
5    * or more contributor license agreements.  See the NOTICE file
6    * distributed with this work for additional information
7    * regarding copyright ownership.  The ASF licenses this file
8    * to you under the Apache License, Version 2.0 (the
9    * "License"); you may not use this file except in compliance
10   * with the License.  You may obtain a copy of the License at
11   *
12   *   http://www.apache.org/licenses/LICENSE-2.0
13   *
14   * Unless required by applicable law or agreed to in writing,
15   * software distributed under the License is distributed on an
16   * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
17   * KIND, either express or implied.  See the License for the
18   * specific language governing permissions and limitations
19   * under the License.
20   */
21  
22  import java.util.Locale;
23  import java.util.MissingResourceException;
24  
25  import org.apache.commons.logging.Log;
26  import org.apache.commons.logging.LogFactory;
27  import org.apache.fulcrum.localization.LocalizationService;
28  import org.apache.turbine.services.InstantiationException;
29  import org.apache.turbine.services.TurbineServices;
30  import org.apache.turbine.services.pull.ApplicationTool;
31  import org.apache.turbine.util.RunData;
32  /**
33   * A pull tool which provides lookups for localized text by delegating
34   * to the configured Fulcrum <code>LocalizationService</code>.
35   *
36   * @author <a href="mailto:epugh@upstate.com">Eric Pugh</a>
37   * @author <a href="mailto:dlr@collab.net">Daniel Rall</a>
38   * @author <a href="mailto:jon@collab.net">Jon Stevens</a>
39   */
40  public class LocalizationTool implements ApplicationTool
41  {
42      /** Logging */
43      private static Log log = LogFactory.getLog(LocalizationTool.class);
44      /** Fulcrum Localization component */
45      private LocalizationService localizationService;
46      /**
47       * The language and country information parsed from the request's
48       * <code>Accept-Language</code> header.  Reset on each request.
49       */
50      protected Locale locale;
51  
52      /**
53       * Lazy load the LocalizationService.
54       * @return a fulcrum LocalizationService
55       */
56      public LocalizationService getLocalizationService()
57      {
58          if (localizationService == null)
59          {
60              try
61              {
62                  localizationService = (LocalizationService)TurbineServices.getInstance()
63                      .getService(LocalizationService.ROLE);
64              }
65              catch (Exception e)
66              {
67                  throw new InstantiationException("Problem looking up Localization Service:"+e.getMessage());
68              }
69          }
70          return localizationService;
71      }
72  
73      /**
74       * Creates a new instance.  Used by <code>PullService</code>.
75       */
76      public LocalizationTool()
77      {
78          refresh();
79      }
80  
81      /**
82       * <p>Performs text lookups for localization.</p>
83       *
84       * <p>Assuming there is a instance of this class with a HTTP
85       * request set in your template's context named <code>l10n</code>,
86       * the VTL <code>$l10n.HELLO</code> would render to
87       * <code>hello</code> for English requests and <code>hola</code>
88       * in Spanish (depending on the value of the HTTP request's
89       * <code>Accept-Language</code> header).</p>
90       *
91       * @param key The identifier for the localized text to retrieve.
92       * @return The localized text.
93       */
94      public String get(String key)
95      {
96          try
97          {
98              return getLocalizationService().getString(getBundleName(null), getLocale(), key);
99          }
100         catch (MissingResourceException noKey)
101         {
102             log.error(noKey);
103             return null;
104         }
105     }
106 
107     /**
108      * Gets the current locale.
109      *
110      * @return The locale currently in use.
111      */
112     public Locale getLocale()
113     {
114         return locale;
115     }
116 
117     /**
118      * The return value of this method is used to set the name of the
119      * bundle used by this tool.  Useful as a hook for using a
120      * different bundle than specified in your
121      * <code>LocalizationService</code> configuration.
122      *
123      * @param data The inputs passed from {@link #init(Object)}.
124      * (ignored by this implementation).
125      */
126     protected String getBundleName(Object data)
127     {
128         return getLocalizationService().getDefaultBundleName();
129     }
130 
131     /**
132      * Formats a localized value using the provided objects.
133      *
134      * @param key The identifier for the localized text to retrieve,
135      * @param args The objects to use as {0}, {1}, etc. when
136      *             formatting the localized text.
137      * @return Formatted localized text.
138      */
139     public String format(String key, Object... args)
140     {
141         return getLocalizationService()
142                 .format(getBundleName(null), getLocale(), key, args);
143     }
144 
145     // ApplicationTool implementation
146 
147     /**
148      * Sets the request to get the <code>Accept-Language</code> header
149      * from (reset on each request).
150      */
151     @Override
152     public void init(Object data)
153     {
154         if (data instanceof RunData)
155         {
156             // Pull necessary information out of RunData while we have
157             // a reference to it.
158             locale = getLocalizationService().getLocale(((RunData) data).getRequest());
159         }
160     }
161 
162     /**
163      * No-op.
164      */
165     @Override
166     public void refresh()
167     {
168         locale = null;
169     }
170 }