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Java > Open Source Codes > org > apache > jetspeed > services > jsp > tags > EcsScreenTag


1 package org.apache.jetspeed.services.jsp.tags;
2
3 /*
4  * Copyright 2000-2004 The Apache Software Foundation.
5  *
6  * Licensed under the Apache License, Version 2.0 (the "License");
7  * you may not use this file except in compliance with the License.
8  * You may obtain a copy of the License at
9  *
10  * http://www.apache.org/licenses/LICENSE-2.0
11  *
12  * Unless required by applicable law or agreed to in writing, software
13  * distributed under the License is distributed on an "AS IS" BASIS,
14  * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
15  * See the License for the specific language governing permissions and
16  * limitations under the License.
17  */
18
19 import javax.servlet.jsp.JspException JavaDoc;
20 import javax.servlet.jsp.PageContext JavaDoc;
21 import javax.servlet.jsp.tagext.TagSupport JavaDoc;
22
23 // Turbine Classes
24 import org.apache.turbine.modules.ScreenLoader;
25 import org.apache.turbine.util.RunData;
26 import org.apache.turbine.services.jsp.JspService;
27 import org.apache.turbine.services.resources.TurbineResources;
28 import org.apache.ecs.ConcreteElement;
29
30 // Jetspeed classes
31 import org.apache.jetspeed.services.logging.JetspeedLogFactoryService;
32 import org.apache.jetspeed.services.logging.JetspeedLogger;
33
34 /**
35  * Supporting class for the ecsscreen tag.
36  * Sends the screens ecs element's content to the output stream.
37  * RunData's screen value is expected to be set!
38  *
39  * @author <a HREF="mailto:ingo@raleigh.ibm.com">Ingo Schuster</a>
40  * @version $Id: EcsScreenTag.java,v 1.12 2004/02/23 03:59:40 jford Exp $
41  */
42 public class EcsScreenTag extends TagSupport JavaDoc
43 {
44     /**
45      * Static initialization of the logger for this class
46      */
47     private static final JetspeedLogger logger = JetspeedLogFactoryService.getLogger(EcsScreenTag.class.getName());
48     
49     /**
50      * Method called when the tag is encountered to send attributes to the
51      * output stream
52      *
53      * @return SKIP_BODY, as it is intended to be a single tag.
54      */
55     public int doStartTag() throws JspException JavaDoc
56     {
57         RunData data = (RunData)pageContext.getAttribute(JspService.RUNDATA, PageContext.REQUEST_SCOPE);
58         String JavaDoc screenName = data.getScreen();
59
60         // make sure that not the BaseJspScreen is called
61 // as this would result in an endless loop...
62 if ( screenName.equals( "BaseJspScreen" ) )
63         {
64             screenName = TurbineResources.getString("screen.homepage");
65         }
66
67         try
68         {
69             pageContext.getOut().flush();
70
71             ConcreteElement screenElement = ScreenLoader.getInstance().eval( data, screenName );
72
73             // Check whether this is an "old" screen (that returns a ConcreteElement)
74 // or a "new" one that returns null.
75 if ( screenElement != null )
76             {
77                 //The ECS element must serialize in the character encoding
78 // of the response
79 screenElement.setCodeSet( data.getResponse().getCharacterEncoding() );
80
81                 screenElement.output( data.getResponse().getWriter() );
82             }
83
84         }
85     catch (Exception JavaDoc e)
86         {
87             String JavaDoc message = "Error processing ecs screen '" + screenName + "'.";
88             logger.error(message, e);
89             try
90             {
91                 data.getOut().print("Error processing ecs screen '" + screenName + "'. See log for more information.");
92             }
93             catch(java.io.IOException JavaDoc ioe) {}
94         }
95         return SKIP_BODY;
96     }
97 }
98
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