001package org.apache.turbine.modules.layouts;
002
003
004/*
005 * Licensed to the Apache Software Foundation (ASF) under one
006 * or more contributor license agreements.  See the NOTICE file
007 * distributed with this work for additional information
008 * regarding copyright ownership.  The ASF licenses this file
009 * to you under the Apache License, Version 2.0 (the
010 * "License"); you may not use this file except in compliance
011 * with the License.  You may obtain a copy of the License at
012 *
013 *   http://www.apache.org/licenses/LICENSE-2.0
014 *
015 * Unless required by applicable law or agreed to in writing,
016 * software distributed under the License is distributed on an
017 * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
018 * KIND, either express or implied.  See the License for the
019 * specific language governing permissions and limitations
020 * under the License.
021 */
022
023
024import org.apache.commons.lang.StringUtils;
025import org.apache.commons.logging.Log;
026import org.apache.commons.logging.LogFactory;
027import org.apache.turbine.TurbineConstants;
028import org.apache.turbine.annotation.TurbineLoader;
029import org.apache.turbine.annotation.TurbineService;
030import org.apache.turbine.modules.Layout;
031import org.apache.turbine.modules.Screen;
032import org.apache.turbine.modules.ScreenLoader;
033import org.apache.turbine.pipeline.PipelineData;
034import org.apache.turbine.services.velocity.VelocityService;
035import org.apache.turbine.util.RunData;
036import org.apache.turbine.util.template.TemplateNavigation;
037import org.apache.velocity.context.Context;
038
039/**
040 * This Layout module allows Velocity templates to be used as layouts.
041 * Since dynamic content is supposed to be primarily located in
042 * screens and navigations there should be relatively few reasons to
043 * subclass this Layout.
044 *
045 * To get the same functionality as with VelocityECSLayout, you can use two
046 * supplied VelocityMacros, TurbineHtmlHead and TurbineHtmlBodyAttributes
047 * in your templates. These are used to put HtmlPageAttributes into a page
048 * before rendering.
049 *
050 * Use these macros should be used in the Layout template like this:
051 *
052 * ... set things like style sheets, scripts here.
053 * <html>
054 * #TurbineHtmlHead()
055 * <body #TurbineHtmlBodyAttributes() >
056 *  .... your body information
057 * </body>
058 * </html>
059 *
060 * As the layout template is rendered _after_ the screen template, you
061 * can of course, add information to the $page tool in your screen template.
062 * This will be added correctly to the <head>...</head> and
063 * <body> tags.
064 *
065 * @author <a href="mailto:john.mcnally@clearink.com">John D. McNally</a>
066 * @author <a href="mailto:mbryson@mont.mindspring.com">Dave Bryson</a>
067 * @author <a href="mailto:hps@intermeta.de">Henning P. Schmiedehausen</a>
068 * @author <a href="mailto:peter@courcoux.biz">Peter Courcoux</a>
069 * @version $Id: VelocityOnlyLayout.java 1709648 2015-10-20 17:08:10Z tv $
070 */
071public class VelocityOnlyLayout
072    extends Layout
073{
074    /** Logging */
075    private static Log log = LogFactory.getLog(VelocityOnlyLayout.class);
076
077    /** The prefix for lookup up layout pages */
078    private final String prefix = Layout.PREFIX + "/";
079
080    /** Injected service instance */
081    @TurbineService
082    private VelocityService velocityService;
083
084    /** Injected loader instance */
085    @TurbineLoader( Screen.class )
086    private ScreenLoader screenLoader;
087
088    /**
089     * Build the layout.  Also sets the ContentType and Locale headers
090     * of the HttpServletResponse object.
091     *
092     *
093     * @param pipelineData PipelineData
094     * @throws Exception generic exception
095     */
096    @Override
097    public void doBuild(PipelineData pipelineData)
098        throws Exception
099    {
100        RunData data = getRunData(pipelineData);
101        // Get the context needed by Velocity.
102        Context context = velocityService.getContext(pipelineData);
103
104        String screenName = data.getScreen();
105
106        log.debug("Loading Screen " + screenName);
107
108        // First, generate the screen and put it in the context so
109        // we can grab it the layout template.
110        String results = screenLoader.eval(pipelineData, screenName);
111        String returnValue = StringUtils.defaultIfEmpty(results, StringUtils.EMPTY);
112
113        // variable for the screen in the layout template
114        context.put(TurbineConstants.SCREEN_PLACEHOLDER, returnValue);
115
116        // variable to reference the navigation screen in the layout template
117        context.put(TurbineConstants.NAVIGATION_PLACEHOLDER,
118                    new TemplateNavigation(data));
119
120        // Grab the layout template set in the VelocityPage.
121        // If null, then use the default layout template
122        // (done by the TemplateInfo object)
123        String templateName = data.getTemplateInfo().getLayoutTemplate();
124
125        // Set the locale and content type
126        data.getResponse().setLocale(data.getLocale());
127        data.getResponse().setContentType(data.getContentType());
128
129        log.debug("Now trying to render layout " + templateName);
130
131        // Finally, generate the layout template and send it to the browser
132        velocityService.handleRequest(context,
133                prefix + templateName, data.getResponse().getOutputStream());
134    }
135}