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    1   package org.apache.turbine.pipeline;
    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.IOException;
    25
    26  import org.apache.turbine.Turbine;
    27  import org.apache.turbine.TurbineConstants;
    28  import org.apache.turbine.modules.Page;
    29  import org.apache.turbine.modules.PageLoader;
    30  import org.apache.turbine.services.assemblerbroker.TurbineAssemblerBroker;
    31  import org.apache.turbine.services.template.TemplateService;
    32  import org.apache.turbine.services.template.TurbineTemplate;
    33  import org.apache.turbine.util.RunData;
    34  import org.apache.turbine.util.TurbineException;
    35
    36  /**
    37   * Implements the Page Generation portion of the "Turbine classic"
    38   * processing pipeline (from the Turbine 2.x series).
    39   *
    40   * @author <a href="mailto:epugh@opensourceConnections.com">Eric Pugh</a>
    41   * @author <a href="mailto:peter@courcoux.biz">Peter Courcoux</a>
    42   * @version $Id: ExecutePageValve.java 757213 2009-03-22 16:43:31Z tv $
    43   */
    44  public class ExecutePageValve
    45      extends AbstractValve
    46  {
    47      private TemplateService templateService;
    48      private PageLoader pageLoader;
    49
    50      /**
    51       * Creates a new instance.
    52       */
    53      public ExecutePageValve()
    54      {
    55          // empty constructor
    56      }
    57
    58      /**
    59       * Initialize this valve for use in a pipeline.
    60       *
    61       * @see org.apache.turbine.pipeline.AbstractValve#initialize()
    62       */
    63      public void initialize() throws Exception
    64      {
    65          super.initialize();
    66
    67          this.templateService = TurbineTemplate.getService();
    68          this.pageLoader = (PageLoader)TurbineAssemblerBroker.getLoader(Page.NAME);
    69      }
    70
    71      /**
    72       * @see org.apache.turbine.Valve#invoke(RunData, ValveContext)
    73       */
    74      public void invoke(PipelineData pipelineData, ValveContext context)
    75          throws IOException, TurbineException
    76      {
    77          try
    78          {
    79              executePage(pipelineData);
    80          }
    81          catch (Exception e)
    82          {
    83              throw new TurbineException(e);
    84          }
    85
    86          // Pass control to the next Valve in the Pipeline
    87          context.invokeNext(pipelineData);
    88      }
    89
    90      /**
    91       * execute the page generation.
    92       *
    93       * @param data The run-time data.
    94       */
    95      protected void executePage(PipelineData pipelineData)
    96          throws Exception
    97      {
    98          RunData data = getRunData(pipelineData);
    99
    100         // Start the execution phase. DefaultPage will execute the
    101         // appropriate action as well as get the Layout from the
    102         // Screen and then execute that. The Layout is then
    103         // responsible for executing the Navigation and Screen
    104         // modules.
    105         //
    106         // Note that by default, this cannot be overridden from
    107         // parameters passed in via post/query data. This is for
    108         // security purposes.  You should really never need more
    109         // than just the default page.  If you do, add logic to
    110         // DefaultPage to do what you want.
    111
    112         String defaultPage = (templateService == null)
    113         ? null :templateService.getDefaultPageName(data);
    114
    115         if (defaultPage == null)
    116         {
    117             /*
    118              * In this case none of the template services are running.
    119              * The application may be using ECS for views, or a
    120              * decendent of RawScreen is trying to produce output.
    121              * If there is a 'page.default' property in the TR.props
    122              * then use that, otherwise return DefaultPage which will
    123              * handle ECS view scenerios and RawScreen scenerios. The
    124              * app developer can still specify the 'page.default'
    125              * if they wish but the DefaultPage should work in
    126              * most cases.
    127              */
    128             defaultPage = Turbine.getConfiguration().getString(TurbineConstants.PAGE_DEFAULT_KEY,
    129                     TurbineConstants.PAGE_DEFAULT_DEFAULT);
    130         }
    131
    132         pageLoader.exec(pipelineData, defaultPage);
    133     }
    134 }