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