package org.apache.turbine.pipeline;

 /*

  * Licensed to the Apache Software Foundation (ASF) under one

  * or more contributor license agreements.  See the NOTICE file

  * distributed with this work for additional information

  * regarding copyright ownership.  The ASF licenses this file

  * to you under the Apache License, Version 2.0 (the

  * "License"); you may not use this file except in compliance

  * with the License.  You may obtain a copy of the License at

  *

  *   http://www.apache.org/licenses/LICENSE-2.0

  *

  * Unless required by applicable law or agreed to in writing,

  * software distributed under the License is distributed on an

  * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY

  * KIND, either express or implied.  See the License for the

  * specific language governing permissions and limitations

  * under the License.

  */

 import java.io.IOException;

 import org.apache.turbine.TurbineConstants;

 import org.apache.turbine.annotation.TurbineConfiguration;

 import org.apache.turbine.annotation.TurbineLoader;

 import org.apache.turbine.annotation.TurbineService;

 import org.apache.turbine.modules.Page;

 import org.apache.turbine.modules.PageLoader;

 import org.apache.turbine.services.template.TemplateService;

 import org.apache.turbine.util.TurbineException;

 /**

  * Implements the Page Generation portion of the "Turbine classic"

  * processing pipeline (from the Turbine 2.x series).

  *

  * @author <a href="mailto:epugh@opensourceConnections.com">Eric Pugh</a>

  * @author <a href="mailto:peter@courcoux.biz">Peter Courcoux</a>

  * @version $Id: ExecutePageValve.java 1854797 2019-03-04 20:41:39Z tv $

  */

 public class ExecutePageValve

     implements Valve

 {

     /** Injected service instance */

     @TurbineService

     private TemplateService templateService;

     /** Injected loader instance */

     @TurbineLoader( Page.class )

     private PageLoader pageLoader;

     @TurbineConfiguration( TurbineConstants.PAGE_DEFAULT_KEY )

     private String pageDefault = TurbineConstants.PAGE_DEFAULT_DEFAULT;

     /**

      * @see org.apache.turbine.pipeline.Valve#invoke(PipelineData, ValveContext)

      */

     @Override

     public void invoke(PipelineData pipelineData, ValveContext context)

         throws IOException, TurbineException

     {

         try

         {

             executePage(pipelineData);

         }

         catch (Exception e)

         {

             throw new TurbineException(e);

         }

         // Pass control to the next Valve in the Pipeline

         context.invokeNext(pipelineData);

     }

     /**

      * execute the page generation.

      *

      * @param pipelineData The run-time data.

      *

      * @throws Exception if the page execution fails

      */

     protected void executePage(PipelineData pipelineData)

         throws Exception

     {

         // Start the execution phase. DefaultPage will execute the

         // appropriate action as well as get the Layout from the

         // Screen and then execute that. The Layout is then

         // responsible for executing the Navigation and Screen

         // modules.

         //

         // Note that by default, this cannot be overridden from

         // parameters passed in via post/query data. This is for

         // security purposes.  You should really never need more

         // than just the default page.  If you do, add logic to

         // DefaultPage to do what you want.

         String defaultPage = (templateService == null)

         ? null : templateService.getDefaultPageName(pipelineData);

         if (defaultPage == null)

         {

             /*

              * In this case none of the template services are running.

              * The application may be using ECS for views, or a

              * decendent of RawScreen is trying to produce output.

              * If there is a 'page.default' property in the TR.props

              * then use that, otherwise return DefaultPage which will

              * handle ECS view scenarios and RawScreen scenarios. The

              * app developer can still specify the 'page.default'

              * if they wish but the DefaultPage should work in

              * most cases.

              */

             defaultPage = pageDefault;

         }

         pageLoader.exec(pipelineData, defaultPage);

     }

 }