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1   package org.apache.turbine.services.jsp.util;
2   
3   
4   /*
5    * Licensed to the Apache Software Foundation (ASF) under one
6    * or more contributor license agreements.  See the NOTICE file
7    * distributed with this work for additional information
8    * regarding copyright ownership.  The ASF licenses this file
9    * to you under the Apache License, Version 2.0 (the
10   * "License"); you may not use this file except in compliance
11   * with the License.  You may obtain a copy of the License at
12   *
13   *   http://www.apache.org/licenses/LICENSE-2.0
14   *
15   * Unless required by applicable law or agreed to in writing,
16   * software distributed under the License is distributed on an
17   * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
18   * KIND, either express or implied.  See the License for the
19   * specific language governing permissions and limitations
20   * under the License.
21   */
22  
23  
24  import org.apache.commons.logging.Log;
25  import org.apache.commons.logging.LogFactory;
26  import org.apache.turbine.modules.Screen;
27  import org.apache.turbine.modules.ScreenLoader;
28  import org.apache.turbine.services.TurbineServices;
29  import org.apache.turbine.services.assemblerbroker.AssemblerBrokerService;
30  import org.apache.turbine.services.template.TemplateService;
31  import org.apache.turbine.util.RunData;
32  
33  /**
34   * Returns output of a Screen module. An instance of this is placed in the
35   * request by the JspLayout. This allows template authors to
36   * place the screen template within the layout.<br>
37   * Here's how it's used in a JSP template:<br>
38   * <code>
39   * &lt;%useBean id="screen_placeholder" class="JspScreenPlaceholder" scope="request" %&gt;
40   * ...
41   * &lt;%= screen_placeholder %&gt;
42   * </code>
43   *
44   * @author <a href="john.mcnally@clearink.com">John D. McNally</a>
45   * @author <a href="mailto:hps@intermeta.de">Henning P. Schmiedehausen</a>
46   * @version $Id: JspScreenPlaceholder.java 1773378 2016-12-09 13:19:59Z tv $
47   */
48  public class JspScreenPlaceholder
49  {
50      /** Logging */
51      private static Log log = LogFactory.getLog(JspNavigation.class);
52  
53      /* The RunData object */
54      private final RunData data;
55  
56      private final ScreenLoader screenLoader;
57  
58      /**
59       * Constructor
60       *
61       * @param data A Rundata Object
62       */
63      public JspScreenPlaceholder(RunData data)
64      {
65          this.data = data;
66          AssemblerBrokerService abs = (AssemblerBrokerService)TurbineServices.getInstance()
67              .getService(AssemblerBrokerService.SERVICE_NAME);
68          this.screenLoader = (ScreenLoader)abs.getLoader(Screen.class);
69      }
70  
71      /**
72       * builds the output of the navigation template
73       */
74      public void exec()
75      {
76          String template = null;
77          String module = null;
78          try
79          {
80              template = data.getTemplateInfo().getScreenTemplate();
81              TemplateService templateService = (TemplateService)TurbineServices.getInstance().getService(TemplateService.SERVICE_NAME);
82              module = templateService.getScreenName(template);
83              screenLoader.exec(data, module);
84          }
85          catch (Exception e)
86          {
87              String message = "Error processing navigation template:" +
88                      template + " using module: " + module;
89              log.error(message, e);
90              try
91              {
92                  data.getResponse().getWriter().print("Error processing navigation template: "
93                          + template + " using module: " + module);
94              }
95              catch (java.io.IOException ioe)
96              {
97                  // ignore
98              }
99          }
100     }
101 }