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1   package org.apache.turbine.pipeline;
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 java.io.IOException;
25  
26  import org.apache.turbine.Turbine;
27  import org.apache.turbine.TurbineConstants;
28  import org.apache.turbine.modules.Page;
29  import org.apache.turbine.modules.PageLoader;
30  import org.apache.turbine.services.assemblerbroker.TurbineAssemblerBroker;
31  import org.apache.turbine.services.template.TemplateService;
32  import org.apache.turbine.services.template.TurbineTemplate;
33  import org.apache.turbine.util.RunData;
34  import org.apache.turbine.util.TurbineException;
35  
36  /**
37   * Implements the Page Generation portion of the "Turbine classic"
38   * processing pipeline (from the Turbine 2.x series).
39   *
40   * @author <a href="mailto:epugh@opensourceConnections.com">Eric Pugh</a>
41   * @author <a href="mailto:peter@courcoux.biz">Peter Courcoux</a>
42   * @version $Id: ExecutePageValve.java 757213 2009-03-22 16:43:31Z tv $
43   */
44  public class ExecutePageValve
45      extends AbstractValve
46  {
47      private TemplateService templateService;
48      private PageLoader pageLoader;
49      
50      /**
51       * Creates a new instance.
52       */
53      public ExecutePageValve()
54      {
55          // empty constructor
56      }
57      
58      /**
59       * Initialize this valve for use in a pipeline.
60       * 
61       * @see org.apache.turbine.pipeline.AbstractValve#initialize()
62       */
63      public void initialize() throws Exception
64      {
65          super.initialize();
66          
67          this.templateService = TurbineTemplate.getService();
68          this.pageLoader = (PageLoader)TurbineAssemblerBroker.getLoader(Page.NAME);
69      }
70  
71      /**
72       * @see org.apache.turbine.Valve#invoke(RunData, ValveContext)
73       */
74      public void invoke(PipelineData pipelineData, ValveContext context)
75          throws IOException, TurbineException
76      {
77          try
78          {
79              executePage(pipelineData);
80          }
81          catch (Exception e)
82          {
83              throw new TurbineException(e);
84          }
85  
86          // Pass control to the next Valve in the Pipeline
87          context.invokeNext(pipelineData);
88      }
89  
90      /**
91       * execute the page generation.
92       *
93       * @param data The run-time data.
94       */
95      protected void executePage(PipelineData pipelineData)
96          throws Exception
97      {
98          RunData data = getRunData(pipelineData);
99  
100         // Start the execution phase. DefaultPage will execute the
101         // appropriate action as well as get the Layout from the
102         // Screen and then execute that. The Layout is then
103         // responsible for executing the Navigation and Screen
104         // modules.
105         //
106         // Note that by default, this cannot be overridden from
107         // parameters passed in via post/query data. This is for
108         // security purposes.  You should really never need more
109         // than just the default page.  If you do, add logic to
110         // DefaultPage to do what you want.
111 
112         String defaultPage = (templateService == null)
113         ? null :templateService.getDefaultPageName(data);
114 
115         if (defaultPage == null)
116         {
117             /*
118              * In this case none of the template services are running.
119              * The application may be using ECS for views, or a
120              * decendent of RawScreen is trying to produce output.
121              * If there is a 'page.default' property in the TR.props
122              * then use that, otherwise return DefaultPage which will
123              * handle ECS view scenerios and RawScreen scenerios. The
124              * app developer can still specify the 'page.default'
125              * if they wish but the DefaultPage should work in
126              * most cases.
127              */
128             defaultPage = Turbine.getConfiguration().getString(TurbineConstants.PAGE_DEFAULT_KEY,
129                     TurbineConstants.PAGE_DEFAULT_DEFAULT);
130         }
131 
132         pageLoader.exec(pipelineData, defaultPage);
133     }
134 }