1 package org.apache.turbine.modules.pages;
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.turbine.annotation.TurbineService;
25 import org.apache.turbine.pipeline.PipelineData;
26 import org.apache.turbine.services.template.TemplateService;
27 import org.apache.turbine.util.RunData;
28 import org.apache.turbine.util.TurbineException;
29
30 /**
31 * When building sites using templates, Screens need only be defined
32 * for templates which require dynamic (database or object) data.
33 *
34 * <p>
35 *
36 * This page can be used on sites where the number of Screens can be
37 * much less than the number of templates. The templates can be
38 * grouped in directories with common layouts. Screen modules are
39 * then expected to be placed in packages corresponding with the
40 * templates' directories and follow a specific naming scheme.
41 *
42 * <p>
43 *
44 * The template parameter is parsed and and a Screen whose package
45 * matches the templates path and shares the same name minus any
46 * extension and beginning with a capital letter is searched for. If
47 * not found, a Screen in a package matching the template's path with
48 * name Default is searched for. If still not found, a Screen with
49 * name Default is looked for in packages corresponding to parent
50 * directories in the template's path until a match is found.
51 *
52 * <p>
53 *
54 * For example if data.getParameters().getString("template") returns
55 * /about_us/directions/driving.wm, the search follows
56 * about_us.directions.Driving, about_us.directions.Default,
57 * about_us.Default, Default, WebMacroSiteScreen (i.e. the default
58 * screen set in TurbineResources).
59 *
60 * <p>
61 *
62 * Only one Layout module is used, since it is expected that any
63 * dynamic content will be placed in navigations and screens. The
64 * layout template to be used is found in a similar way to the Screen.
65 * For example the following paths will be searched in the layouts
66 * subdirectory: /about_us/directions/driving.wm,
67 * /about_us/directions/default.wm, /about_us/default.wm, /default.wm,
68 * where wm is the value of the template.default.extension property.
69 *
70 * <p>
71 *
72 * This approach allows a site with largely static content to be
73 * updated and added to regularly by those with little Java
74 * experience.
75 *
76 * @author <a href="mailto:john.mcnally@clearink.com">John D. McNally</a>
77 * @author <a href="mailto:mbryson@mont.mindspring.com">Dave Bryson</a>
78 * @author <a href="mailto:hps@intermeta.de">Henning P. Schmiedehausen</a>
79 * @author <a href="mailto:peter@courcoux.biz">Peter Courcoux</a>
80 * @version $Id$
81 */
82 public class TemplatePage
83 extends DefaultPage
84 {
85 /** Injected service instance */
86 @TurbineService
87 private TemplateService templateService;
88
89 /**
90 * Works with TemplateService to set up default templates and
91 * corresponding class modules.
92 *
93 * @param pipelineData Turbine information.
94 * @throws Exception a generic exception.
95 */
96 @Override
97 protected void doBuildAfterAction(PipelineData pipelineData)
98 throws Exception
99 {
100 RunData data = pipelineData.getRunData();
101 // The Template Service at this point must fetch the Screen class
102 // to match a given template. If the Screen class has already been
103 // set by an action, skip this, because the user has the already
104 // specified the Screen class he wants to use.
105 if (!data.hasScreen())
106 {
107 // This is effectively getting the "template" parameter
108 // from the parameter parser in rundata. This is coming
109 // from the request for a template.
110 String template = data.getTemplateInfo().getScreenTemplate();
111
112 // Get the layout template and the correct Screen.
113 String layoutTemplate =
114 templateService.getLayoutTemplateName(template);
115 data.getTemplateInfo().setLayoutTemplate(layoutTemplate);
116
117 String screen = templateService.getScreenName(template);
118
119 if (screen == null)
120 {
121 String errMsg = "Couldn't map Template "
122 + template + " to any Screen class!";
123 log.error(errMsg);
124 throw new TurbineException(errMsg);
125 }
126 data.setScreen(screen);
127 }
128 }
129 }