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1   /*
2    * $Id: HtmlRenderer.java 471754 2006-11-06 14:55:09Z husted $
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  package org.apache.struts.faces.renderer;
23  
24  
25  import java.io.IOException;
26  import java.util.Locale;
27  import javax.faces.component.UIComponent;
28  import javax.faces.context.FacesContext;
29  import javax.faces.context.ResponseWriter;
30  import javax.servlet.http.HttpSession;
31  import org.apache.commons.logging.Log;
32  import org.apache.commons.logging.LogFactory;
33  import org.apache.struts.Globals;
34  
35  
36  /**
37   * <p><code>Renderer</code> implementation for the <code>html</code> tag
38   * from the <em>Struts-Faces Integration Library</em>.</p>
39   *
40   * @version $Rev: 471754 $ $Date: 2006-11-06 08:55:09 -0600 (Mon, 06 Nov 2006) $
41   */
42  
43  public class HtmlRenderer extends AbstractRenderer {
44  
45  
46      // -------------------------------------------------------- Static Variables
47  
48  
49      /**
50       * <p>The <code>Log</code> instance for this class.</p>
51       */
52      private static Log log = LogFactory.getLog(HtmlRenderer.class);
53  
54  
55      // ---------------------------------------------------------- Public Methods
56  
57  
58      /**
59       * <p>Render the beginning <code>html</code> tag.</p>
60       *
61       * @param context FacesContext for the current request
62       * @param component UIComponent to be rendered
63       *
64       * @exception IOException if an input/output error occurs while rendering
65       * @exception NullPointerException if <code>context</code>
66       *  or <code>component</code> is <code>null</code>
67       */
68      public void encodeBegin(FacesContext context, UIComponent component)
69          throws IOException {
70  
71          if ((context == null) || (component == null)) {
72              throw new NullPointerException();
73          }
74  
75          Locale currentLocale = getCurrentLocale(context, component);
76          String lang = currentLocale.getLanguage();
77          boolean validLanguage = ((lang != null) && (lang.length() > 0));
78  
79          ResponseWriter writer = context.getResponseWriter();
80          writer.startElement("html", component);
81          if (isXhtml(component)) {
82              // FIXME -- page scope attribute Globals.XHTML_KEY to "true"?
83              writer.writeAttribute("xmlns",
84                                    "http://www.w3.org/1999/xhtml", null);
85          }
86          if ((isLocale(component) || isXhtml(component)) && validLanguage) {
87              writer.writeAttribute("lang", lang, null);
88          }
89          if (isXhtml(component) && validLanguage) {
90              writer.writeAttribute("xml:lang", lang, null);
91          }
92          writer.writeText("\n", null);
93  
94      }
95  
96  
97      /**
98       * <p>Render the end of the <code>html</code> element.</p>
99       *
100      * @param context FacesContext for the request we are processing
101      * @param component UIComponent to be rendered
102      *
103      * @exception IOException if an input/output error occurs while rendering
104      * @exception NullPointerException if <code>context</code>
105      *  or <code>component</code> is null
106      */
107     public void encodeEnd(FacesContext context, UIComponent component)
108         throws IOException {
109 
110         if ((context == null) || (component == null)) {
111             throw new NullPointerException();
112         }
113 
114         ResponseWriter writer = context.getResponseWriter();
115         writer.endElement("html");
116 
117     }
118 
119 
120 
121     // ------------------------------------------------------ Protected Methods
122 
123 
124     /**
125      * <p>Return the current <code>Locale</code> for this request, creating a
126      * new one if necessary.</p>
127      *
128      * @param context FacesContext for this request
129      * @param component UIComponent we are rendering
130      */
131     protected Locale getCurrentLocale
132         (FacesContext context, UIComponent component) {
133 
134         // If locale support not requested, just extract one from the request
135         if (!isLocale(component)) {
136             return (context.getExternalContext().getRequestLocale());
137         }
138 
139         // Create a new session if necessary
140         HttpSession session = (HttpSession)
141             context.getExternalContext().getSession(true);
142 
143         // Return current locale or a new one that is created
144         Locale current = (Locale) session.getAttribute(Globals.LOCALE_KEY);
145         if (current != null) {
146             return (current);
147         }
148         current = context.getExternalContext().getRequestLocale();
149         session.setAttribute(Globals.LOCALE_KEY, current);
150         return (current);
151 
152     }
153 
154 
155 
156     /**
157      * <p>Return the state of the <code>locale</code> attribute.</p>
158      *
159      * @param component Component to process
160      */
161     protected boolean isLocale(UIComponent component) {
162 
163         Boolean locale = (Boolean) component.getAttributes().get("locale");
164         if (locale != null) {
165             return locale.booleanValue();
166         } else {
167             return (false);
168         }
169 
170     }
171 
172 
173     /**
174      * <p>Return the state of the <code>xhtml</code> attribute.</p>
175      *
176      * @param component Component to process
177      */
178     protected boolean isXhtml(UIComponent component) {
179 
180         Boolean xhtml = (Boolean) component.getAttributes().get("xhtml");
181         if (xhtml != null) {
182             return xhtml.booleanValue();
183         } else {
184             return (false);
185         }
186 
187     }
188 
189 
190 }