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Java > Open Source Codes > org > apache > struts > faces > renderer > HtmlRenderer


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.renderer;
18
19
20 import java.io.IOException JavaDoc;
21 import java.util.Locale JavaDoc;
22 import javax.faces.component.UIComponent;
23 import javax.faces.context.FacesContext;
24 import javax.faces.context.ResponseWriter;
25 import javax.servlet.http.HttpSession JavaDoc;
26 import org.apache.commons.logging.Log;
27 import org.apache.commons.logging.LogFactory;
28 import org.apache.struts.Globals;
29
30
31 /**
32  * <p><code>Renderer</code> implementation for the <code>html</code> tag
33  * from the <em>Struts-Faces Integration Library</em>.</p>
34  *
35  * @version $Rev: 54934 $ $Date: 2004-10-16 18:07:50 +0100 (Sat, 16 Oct 2004) $
36  */
37
38 public class HtmlRenderer extends AbstractRenderer {
39
40
41     // -------------------------------------------------------- Static Variables
42
43
44     /**
45      * <p>The <code>Log</code> instance for this class.</p>
46      */
47     private static Log log = LogFactory.getLog(HtmlRenderer.class);
48
49
50     // ---------------------------------------------------------- Public Methods
51
52
53     /**
54      * <p>Render the beginning <code>html</code> tag.</p>
55      *
56      * @param context FacesContext for the current request
57      * @param component UIComponent to be rendered
58      *
59      * @exception IOException if an input/output error occurs while rendering
60      * @exception NullPointerException if <code>context</code>
61      * or <code>component</code> is <code>null</code>
62      */
63     public void encodeBegin(FacesContext context, UIComponent component)
64         throws IOException JavaDoc {
65
66         if ((context == null) || (component == null)) {
67             throw new NullPointerException JavaDoc();
68         }
69
70         Locale JavaDoc currentLocale = getCurrentLocale(context, component);
71         String JavaDoc lang = currentLocale.getLanguage();
72         boolean validLanguage = ((lang != null) && (lang.length() > 0));
73
74         ResponseWriter writer = context.getResponseWriter();
75         writer.startElement("html", component);
76         if (isXhtml(component)) {
77             // FIXME -- page scope attribute Globals.XHTML_KEY to "true"?
78 writer.writeAttribute("xmlns",
79                                   "http://www.w3.org/1999/xhtml", null);
80         }
81         if ((isLocale(component) || isXhtml(component)) && validLanguage) {
82             writer.writeAttribute("lang", lang, null);
83         }
84         if (isXhtml(component) && validLanguage) {
85             writer.writeAttribute("xml:lang", lang, null);
86         }
87         writer.writeText("\n", null);
88
89     }
90
91
92     /**
93      * <p>Render the end of the <code>html</code> element.</p>
94      *
95      * @param context FacesContext for the request we are processing
96      * @param component UIComponent to be rendered
97      *
98      * @exception IOException if an input/output error occurs while rendering
99      * @exception NullPointerException if <code>context</code>
100      * or <code>component</code> is null
101      */
102     public void encodeEnd(FacesContext context, UIComponent component)
103         throws IOException JavaDoc {
104
105         if ((context == null) || (component == null)) {
106             throw new NullPointerException JavaDoc();
107         }
108
109         ResponseWriter writer = context.getResponseWriter();
110         writer.endElement("html");
111
112     }
113
114
115
116     // ------------------------------------------------------ Protected Methods
117
118
119     /**
120      * <p>Return the current <code>Locale</code> for this request, creating a
121      * new one if necessary.</p>
122      *
123      * @param context FacesContext for this request
124      * @param component UIComponent we are rendering
125      */
126     protected Locale JavaDoc getCurrentLocale
127         (FacesContext context, UIComponent component) {
128
129         // If locale support not requested, just extract one from the request
130 if (!isLocale(component)) {
131             return (context.getExternalContext().getRequestLocale());
132         }
133
134         // Create a new session if necessary
135 HttpSession JavaDoc session = (HttpSession JavaDoc)
136             context.getExternalContext().getSession(true);
137
138         // Return current locale or a new one that is created
139 Locale JavaDoc current = (Locale JavaDoc) session.getAttribute(Globals.LOCALE_KEY);
140         if (current != null) {
141             return (current);
142         }
143         current = context.getExternalContext().getRequestLocale();
144         session.setAttribute(Globals.LOCALE_KEY, current);
145         return (current);
146
147     }
148
149
150
151     /**
152      * <p>Return the state of the <code>locale</code> attribute.</p>
153      *
154      * @param component Component to process
155      */
156     protected boolean isLocale(UIComponent component) {
157
158         Boolean JavaDoc locale = (Boolean JavaDoc) component.getAttributes().get("locale");
159         if (locale != null) {
160             return locale.booleanValue();
161         } else {
162             return (false);
163         }
164
165     }
166
167
168     /**
169      * <p>Return the state of the <code>xhtml</code> attribute.</p>
170      *
171      * @param component Component to process
172      */
173     protected boolean isXhtml(UIComponent component) {
174
175         Boolean JavaDoc xhtml = (Boolean JavaDoc) component.getAttributes().get("xhtml");
176         if (xhtml != null) {
177             return xhtml.booleanValue();
178         } else {
179             return (false);
180         }
181
182     }
183
184
185 }
186
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