    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.logging.Log;
    025import org.apache.commons.logging.LogFactory;
    026import org.apache.turbine.TurbineConstants;
    027import org.apache.turbine.annotation.TurbineService;
    028import org.apache.turbine.modules.Layout;
    029import org.apache.turbine.pipeline.PipelineData;
    030import org.apache.turbine.services.velocity.VelocityService;
    031import org.apache.turbine.util.RunData;
    032import org.apache.turbine.util.template.TemplateNavigation;
    033import org.apache.turbine.util.template.TemplateScreen;
    034import org.apache.velocity.context.Context;
    035
    036/**
    037 * This Layout module allows Velocity templates
    038 * to be used as layouts. It will stream directly the output of
    039 * the layout and navigation templates to the output writer without
    040 * using a screen. Use this if you have a large page to output
    041 * and won't buffer it in the memory.
    042 *
    043 * @author <a href="mailto:raphael@apache.org">Raphaël Luta</a>
    044 * @author <a href="mailto:john.mcnally@clearink.com">John D. McNally</a>
    045 * @author <a href="mailto:mbryson@mont.mindspring.com">Dave Bryson</a>
    046 * @author <a href="mailto:hps@intermeta.de">Henning P. Schmiedehausen</a>
    047 * @author <a href="mailto:peter@courcoux.biz">Peter Courcoux</a>
    048 * @version $Id: VelocityDirectLayout.java 1706239 2015-10-01 13:18:35Z tv $
    049 */
    050public class VelocityDirectLayout
    051    extends Layout
    052{
    053    /** Logging */
    054    private static Log log = LogFactory.getLog(VelocityDirectLayout.class);
    055
    056    /** The prefix for lookup up layout pages */
    057    private String prefix = Layout.PREFIX + "/";
    058
    059    /** Injected service instance */
    060    @TurbineService
    061    private VelocityService velocityService;
    062
    063    /**
    064     * Method called by LayoutLoader.
    065     *
    066     *
    067     * @param pipelineData PipelineData
    068     * @throws Exception generic exception
    069     */
    070    @Override
    071    public void doBuild(PipelineData pipelineData)
    072        throws Exception
    073    {
    074        RunData data = getRunData(pipelineData);
    075        // Get the context needed by Velocity.
    076        Context context = velocityService.getContext(pipelineData);
    077
    078        // variable for the screen in the layout template
    079        context.put(TurbineConstants.SCREEN_PLACEHOLDER,
    080                    new TemplateScreen(data));
    081
    082        // variable to reference the navigation screen in the layout template
    083        context.put(TurbineConstants.NAVIGATION_PLACEHOLDER,
    084                    new TemplateNavigation(data));
    085
    086        // Grab the layout template set in the VelocityPage.
    087        // If null, then use the default layout template
    088        // (done by the TemplateInfo object)
    089        String templateName = data.getTemplateInfo().getLayoutTemplate();
    090
    091        // Set the locale and content type
    092        data.getResponse().setLocale(data.getLocale());
    093        data.getResponse().setContentType(data.getContentType());
    094
    095        log.debug("Now trying to render layout " + templateName);
    096
    097        // Finally, generate the layout template and send it to the browser
    098        velocityService.handleRequest(context,
    099                prefix + templateName, data.getResponse().getOutputStream());
    100    }
    101
    102
    103}