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    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.logging.Log;
    25  import org.apache.commons.logging.LogFactory;
    26  import org.apache.turbine.TurbineConstants;
    27  import org.apache.turbine.annotation.TurbineService;
    28  import org.apache.turbine.modules.Layout;
    29  import org.apache.turbine.pipeline.PipelineData;
    30  import org.apache.turbine.services.velocity.VelocityService;
    31  import org.apache.turbine.util.RunData;
    32  import org.apache.turbine.util.template.TemplateNavigation;
    33  import org.apache.turbine.util.template.TemplateScreen;
    34  import org.apache.velocity.context.Context;
    35
    36  /**
    37   * This Layout module allows Velocity templates
    38   * to be used as layouts. It will stream directly the output of
    39   * the layout and navigation templates to the output writer without
    40   * using a screen. Use this if you have a large page to output
    41   * and won't buffer it in the memory.
    42   *
    43   * @author <a href="mailto:raphael@apache.org">Raphaël Luta</a>
    44   * @author <a href="mailto:john.mcnally@clearink.com">John D. McNally</a>
    45   * @author <a href="mailto:mbryson@mont.mindspring.com">Dave Bryson</a>
    46   * @author <a href="mailto:hps@intermeta.de">Henning P. Schmiedehausen</a>
    47   * @author <a href="mailto:peter@courcoux.biz">Peter Courcoux</a>
    48   * @version $Id: VelocityDirectLayout.java 1706239 2015-10-01 13:18:35Z tv $
    49   */
    50  public class VelocityDirectLayout
    51      extends Layout
    52  {
    53      /** Logging */
    54      private static Log log = LogFactory.getLog(VelocityDirectLayout.class);
    55
    56      /** The prefix for lookup up layout pages */
    57      private String prefix = Layout.PREFIX + "/";
    58
    59      /** Injected service instance */
    60      @TurbineService
    61      private VelocityService velocityService;
    62
    63      /**
    64       * Method called by LayoutLoader.
    65       *
    66       *
    67       * @param pipelineData PipelineData
    68       * @throws Exception generic exception
    69       */
    70      @Override
    71      public void doBuild(PipelineData pipelineData)
    72          throws Exception
    73      {
    74          RunData data = getRunData(pipelineData);
    75          // Get the context needed by Velocity.
    76          Context context = velocityService.getContext(pipelineData);
    77
    78          // variable for the screen in the layout template
    79          context.put(TurbineConstants.SCREEN_PLACEHOLDER,
    80                      new TemplateScreen(data));
    81
    82          // variable to reference the navigation screen in the layout template
    83          context.put(TurbineConstants.NAVIGATION_PLACEHOLDER,
    84                      new TemplateNavigation(data));
    85
    86          // Grab the layout template set in the VelocityPage.
    87          // If null, then use the default layout template
    88          // (done by the TemplateInfo object)
    89          String templateName = data.getTemplateInfo().getLayoutTemplate();
    90
    91          // Set the locale and content type
    92          data.getResponse().setLocale(data.getLocale());
    93          data.getResponse().setContentType(data.getContentType());
    94
    95          log.debug("Now trying to render layout " + templateName);
    96
    97          // Finally, generate the layout template and send it to the browser
    98          velocityService.handleRequest(context,
    99                  prefix + templateName, data.getResponse().getOutputStream());
    100     }
    101
    102
    103 }