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1   /*
2    * Copyright 2002,2004 The Apache Software Foundation.
3    *
4    * Licensed under the Apache License, Version 2.0 (the "License");
5    * you may not use this file except in compliance with the License.
6    * You may obtain a copy of the License at
7    *
8    *      http://www.apache.org/licenses/LICENSE-2.0
9    *
10   * Unless required by applicable law or agreed to in writing, software
11   * distributed under the License is distributed on an "AS IS" BASIS,
12   * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
13   * See the License for the specific language governing permissions and
14   * limitations under the License.
15   */
16  
17  package org.apache.struts.faces.taglib;
18  
19  
20  import java.util.Locale;
21  
22  import javax.faces.context.FacesContext;
23  
24  import javax.servlet.jsp.PageContext;
25  import javax.servlet.jsp.tagext.TagSupport;
26  
27  import org.apache.struts.Globals;
28  import org.apache.struts.faces.util.MessagesMap;
29  import org.apache.struts.util.MessageResources;
30  
31  
32  /***
33   * <p>Tag that exposes a specified <code>MessageResources</code> instance
34   * as <code>Map</code>, so that the embedded messages may be retrieved via
35   * value binding expressions.</p>
36   */
37  
38  public class LoadMessagesTag extends TagSupport {
39  
40  
41      // ---------------------------------------------------------- Tag Attributes
42  
43  
44      /***
45       * <p>The name of the <code>MessageResources</code> to expose, or
46       * <code>null</code> for the default <code>MessageResources</code>
47       * for this application module.</p>
48       */
49      private String messages = null;
50      public void setMessages(String messages) {
51          this.messages = messages;
52      }
53  
54  
55      /***
56       * <p>The request attribute key under which a <code>Map</code>
57       * will be exposed.</p>
58       */
59      private String var = null;
60      public void setVar(String var) {
61          this.var = var;
62      }
63  
64  
65      // ------------------------------------------------------------- Tag Methods
66  
67  
68      /***
69       * <p>Expose a <code>Map</code> wrapping the specified
70       * <code>MessageResources</code> instance, for the <code>Locale</code>
71       * specified in the view root component of the current view.</p>
72       */
73      public int doStartTag() {
74  
75          // Acquire the Locale to be wrapped
76          Locale locale =
77              FacesContext.getCurrentInstance().getViewRoot().getLocale();
78  
79          // Acquire the MessageResources to be wrapped
80          MessageResources messages = null;
81          if (this.messages == null) {
82              messages = (MessageResources)
83                  pageContext.getAttribute(Globals.MESSAGES_KEY,
84                                           PageContext.REQUEST_SCOPE);
85              if (messages == null) {
86                  messages = (MessageResources)
87                      pageContext.getAttribute(Globals.MESSAGES_KEY,
88                                               PageContext.APPLICATION_SCOPE);
89              }
90          } else {
91              messages = (MessageResources)
92                  pageContext.getAttribute(this.messages,
93                                           PageContext.APPLICATION_SCOPE);
94          }
95  
96          // Expose a Map instance under the specified request attribute key
97          pageContext.setAttribute(var,
98                                   new MessagesMap(messages, locale),
99                                   PageContext.REQUEST_SCOPE);
100 
101         // Skip the body of this tag (if any)
102         return (SKIP_BODY);
103 
104     }
105 
106 
107     /***
108      * <p>Release any resources allocated by this tag instance.</p>
109      */
110     public void release() {
111 
112         this.messages = null;
113         this.var = null;
114 
115     }
116 
117 
118 }