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Java > Open Source Codes > org > apache > struts > faces > application > ViewHandlerImpl


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.application;
18
19
20 import java.io.IOException JavaDoc;
21 import java.util.Locale JavaDoc;
22 import javax.faces.FacesException;
23 import javax.faces.application.ViewHandler;
24 import javax.faces.component.UIViewRoot;
25 import javax.faces.context.ExternalContext;
26 import javax.faces.context.FacesContext;
27
28 import org.apache.commons.logging.Log;
29 import org.apache.commons.logging.LogFactory;
30 import org.apache.struts.Globals;
31
32
33 /**
34  * <p>Custom <code>ViewHandler</code> implementation that adds features
35  * specific to the Struts-Faces Integration Library. It leverages the
36  * "decorator pattern" customization strategy that JSF supports, by
37  * delegating most processing to the <code>ViewHandler</code> instance
38  * handed to our constructor.</p>
39  */
40
41 public class ViewHandlerImpl extends ViewHandler {
42
43
44     // ------------------------------------------------------------ Constructors
45
46
47     /**
48      * <p>Construct a <code>ViewHandlerImpl</code> decorating the
49      * specified <code>ViewHandler</code> instance.</p>
50      *
51      * @param handler <code>ViewHandler</code> to be decorated
52      */
53     public ViewHandlerImpl(ViewHandler handler) {
54         if (log.isDebugEnabled()) {
55             log.debug("Creating ViewHandler instance, wrapping handler " +
56                       handler);
57         }
58         this.handler = handler;
59     }
60
61
62     // ------------------------------------------------------ Instance Variables
63
64
65     /**
66      * <p>The <code>ViewHandler</code> instance that we are decorating.</p>
67      */
68     private ViewHandler handler = null;
69
70
71     // -------------------------------------------------------- Static Variables
72
73
74     /**
75      * <p>The <code>Log</code> instance for this class.</p>
76      */
77     private static final Log log =
78         LogFactory.getLog(ViewHandlerImpl.class);
79
80
81
82     // -------------------------------------------------------------- Properties
83
84
85     /**
86      * <p>Return the <code>ViewHandler</code> instance we are decorating.</p>
87      */
88     public ViewHandler getHandler() {
89         return this.handler;
90     }
91
92
93     /**
94      * <p>Set the <code>ViewHandler</code> instance we are decorating.</p>
95      *
96      * @param handler <code>ViewHandler</code> instance to decorate
97      */
98     public void setHandler(ViewHandler handler) {
99         this.handler = handler;
100     }
101
102
103     // ----------------------------------------------------- Specialized Methods
104
105
106     /**
107      * <p>If the Struts application has set a <code>Locale</code>, pass it
108      * on to JSF prior to delegating the actual rendering.</p>
109      *
110      * @param context <code>FacesContext</code> for the current request
111      * @param view <code>UIViewRoot</code> to be rendered
112      */
113     public void renderView(FacesContext context, UIViewRoot view)
114         throws IOException JavaDoc, FacesException {
115
116         if (log.isDebugEnabled()) {
117             log.debug("renderView(" + view.getViewId() + ")");
118         }
119         ExternalContext econtext = context.getExternalContext();
120         if (econtext.getSession(false) != null) {
121             Locale JavaDoc locale = (Locale JavaDoc)
122                 econtext.getSessionMap().get(Globals.LOCALE_KEY);
123             if (locale != null) {
124                 if (log.isTraceEnabled()) {
125                     log.trace("Setting view locale to " + locale);
126                 }
127                 view.setLocale(locale);
128             }
129         }
130         handler.renderView(context, view);
131
132     }
133
134
135     // ------------------------------------------------------- Delegated Methods
136
137
138     // See ViewHandler JavaDocs for method descriptions
139
140
141     public Locale JavaDoc calculateLocale(FacesContext context) {
142         return handler.calculateLocale(context);
143     }
144
145
146     public String JavaDoc calculateRenderKitId(FacesContext context) {
147         return handler.calculateRenderKitId(context);
148     }
149
150
151     public UIViewRoot createView(FacesContext context, String JavaDoc viewId) {
152         return handler.createView(context, viewId);
153     }
154
155
156     public String JavaDoc getActionURL(FacesContext context, String JavaDoc viewId) {
157         return handler.getActionURL(context, viewId);
158     }
159
160
161     public String JavaDoc getResourceURL(FacesContext context, String JavaDoc viewId) {
162         return handler.getResourceURL(context, viewId);
163     }
164
165
166     public UIViewRoot restoreView(FacesContext context, String JavaDoc viewId) {
167         return handler.restoreView(context, viewId);
168     }
169
170
171     public void writeState(FacesContext context) throws IOException JavaDoc {
172         handler.writeState(context);
173     }
174
175
176 }
177
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