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 java.io.StringReader;
25
26 import org.apache.commons.lang.StringUtils;
27 import org.apache.commons.logging.Log;
28 import org.apache.commons.logging.LogFactory;
29 import org.apache.fulcrum.xslt.XSLTService;
30 import org.apache.turbine.TurbineConstants;
31 import org.apache.turbine.annotation.TurbineLoader;
32 import org.apache.turbine.annotation.TurbineService;
33 import org.apache.turbine.modules.Layout;
34 import org.apache.turbine.modules.Screen;
35 import org.apache.turbine.modules.ScreenLoader;
36 import org.apache.turbine.pipeline.PipelineData;
37 import org.apache.turbine.services.velocity.VelocityService;
38 import org.apache.turbine.util.RunData;
39 import org.apache.turbine.util.template.TemplateNavigation;
40 import org.apache.velocity.context.Context;
41
42 /**
43 * This Layout module allows Velocity XML templates to be used as layouts.
44 * <br><br>
45 * Once the (XML) screen and navigation templates have been inserted into
46 * the layout template the result is transformed with a XSL stylesheet.
47 * The stylesheet (with the same name than the screen template) is loaded
48 * and executed by the XSLT service, so it is important that you correctly
49 * set up your XSLT service. If the named stylsheet does not exist the
50 * default.xsl stylesheet is executed. If default.xsl does not exist
51 * the XML is merely echoed.
52 * <br><br>
53 * Since dynamic content is supposed to be primarily located in
54 * screens and navigations there should be relatively few reasons to
55 * subclass this Layout.
56 *
57 * @author <a href="mailto:leon@opticode.co.za">Leon Messerschmidt</a>
58 * @author <a href="mailto:hps@intermeta.de">Henning P. Schmiedehausen</a>
59 * @version $Id: VelocityXslLayout.java 1773378 2016-12-09 13:19:59Z tv $
60 */
61 public class VelocityXslLayout extends Layout
62 {
63 /** Logging */
64 private static Log log = LogFactory.getLog(VelocityXslLayout.class);
65
66 /** The prefix for lookup up layout pages */
67 private final String prefix = Layout.PREFIX + "/";
68
69 /** Injected service instance */
70 @TurbineService
71 private VelocityService velocityService;
72
73 /** Injected service instance */
74 @TurbineService
75 private XSLTService xsltService;
76
77 /** Injected loader instance */
78 @TurbineLoader( Screen.class )
79 private ScreenLoader screenLoader;
80
81 /**
82 * Build the layout. Also sets the ContentType and Locale headers
83 * of the HttpServletResponse object.
84 *
85 * @param pipelineData Turbine information.
86 * @throws Exception a generic exception.
87 */
88 @Override
89 public void doBuild(PipelineData pipelineData)
90 throws Exception
91 {
92 RunData data = getRunData(pipelineData);
93 // Get the context needed by Velocity.
94 Context context = velocityService.getContext(pipelineData);
95
96 data.getResponse().setContentType("text/html");
97
98 String screenName = data.getScreen();
99
100 log.debug("Loading Screen " + screenName);
101
102 // First, generate the screen and put it in the context so
103 // we can grab it the layout template.
104 String results = screenLoader.eval(pipelineData, screenName);
105 String returnValue = StringUtils.defaultIfEmpty(results, StringUtils.EMPTY);
106
107 // variable for the screen in the layout template
108 context.put(TurbineConstants.SCREEN_PLACEHOLDER, returnValue);
109
110 // variable to reference the navigation screen in the layout template
111 context.put(TurbineConstants.NAVIGATION_PLACEHOLDER,
112 new TemplateNavigation(data));
113
114 // Grab the layout template set in the VelocityPage.
115 // If null, then use the default layout template
116 // (done by the TemplateInfo object)
117 String templateName = data.getTemplateInfo().getLayoutTemplate();
118
119 log.debug("Now trying to render layout " + templateName);
120
121 // Now, generate the layout template.
122 String temp = velocityService.handleRequest(context,
123 prefix + templateName);
124
125 // Finally we do a transformation and send the result
126 // back to the browser
127 xsltService.transform(
128 data.getTemplateInfo().getScreenTemplate(),
129 new StringReader(temp), data.getResponse().getWriter());
130 }
131 }