1 package org.apache.turbine.modules.layouts;
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.lang3.StringUtils;
25 import org.apache.turbine.TurbineConstants;
26 import org.apache.turbine.annotation.TurbineLoader;
27 import org.apache.turbine.modules.Screen;
28 import org.apache.turbine.modules.ScreenLoader;
29 import org.apache.turbine.pipeline.PipelineData;
30 import org.apache.turbine.util.template.TemplateNavigation;
31 import org.apache.velocity.context.Context;
32
33 /**
34 * This Layout module allows Velocity templates to be used as layouts.
35 * Since dynamic content is supposed to be primarily located in
36 * screens and navigations there should be relatively few reasons to
37 * subclass this Layout.
38 *
39 * To get the same functionality as with VelocityECSLayout, you can use two
40 * supplied VelocityMacros, TurbineHtmlHead and TurbineHtmlBodyAttributes
41 * in your templates. These are used to put HtmlPageAttributes into a page
42 * before rendering.
43 *
44 * Use these macros should be used in the Layout template like this:
45 *
46 * ... set things like style sheets, scripts here.
47 * <html>
48 * #TurbineHtmlHead()
49 * <body #TurbineHtmlBodyAttributes() >
50 * .... your body information
51 * </body>
52 * </html>
53 *
54 * As the layout template is rendered _after_ the screen template, you
55 * can of course, add information to the $page tool in your screen template.
56 * This will be added correctly to the <head>...</head> and
57 * <body> tags.
58 *
59 * @author <a href="mailto:john.mcnally@clearink.com">John D. McNally</a>
60 * @author <a href="mailto:mbryson@mont.mindspring.com">Dave Bryson</a>
61 * @author <a href="mailto:hps@intermeta.de">Henning P. Schmiedehausen</a>
62 * @author <a href="mailto:peter@courcoux.biz">Peter Courcoux</a>
63 * @version $Id$
64 */
65 public class VelocityOnlyLayout extends VelocityLayout
66 {
67 /** Injected loader instance */
68 @TurbineLoader( Screen.class )
69 private ScreenLoader screenLoader;
70
71 /**
72 * @see org.apache.turbine.modules.layouts.VelocityLayout#populateContext(org.apache.turbine.pipeline.PipelineData, org.apache.velocity.context.Context)
73 */
74 @Override
75 protected void populateContext(PipelineData pipelineData, Context context) throws Exception
76 {
77 String screenName = pipelineData.getRunData().getScreen();
78
79 log.debug("Loading Screen {}", screenName);
80
81 // First, generate the screen and put it in the context so
82 // we can grab it the layout template.
83 String results = screenLoader.eval(pipelineData, screenName);
84 String returnValue = StringUtils.defaultIfEmpty(results, StringUtils.EMPTY);
85
86 // variable for the screen in the layout template
87 context.put(TurbineConstants.SCREEN_PLACEHOLDER, returnValue);
88
89 // variable to reference the navigation screen in the layout template
90 context.put(TurbineConstants.NAVIGATION_PLACEHOLDER,
91 new TemplateNavigation(pipelineData));
92 }
93 }