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.logging.log4j.LogManager;

 import org.apache.logging.log4j.Logger;

 import org.apache.turbine.util.RunData;

 import org.apache.turbine.util.TurbineException;

 import org.apache.turbine.util.uri.URIConstants;

 /**

  * This valve is responsible for setting the 'target' property of the RunData.

  * If it is not already set it attempts to get the target from the request

  * parameter 'template'. If the parameter is not set, we use the homepage

  * specified by the configuration property Turbine.TEMPLATE_HOMEPAGE.

  *

  * FIXME: The request parameter which determines the template should be

  *        configurable.

  *

  * @author <a href="mailto:james@jamestaylor.org">James Taylor</a>

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

  */

 public class DetermineTargetValve implements Valve

 {

     private static final Logger log

         = LogManager.getLogger(DetermineTargetValve.class);

     /**

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

      */

     @Override

     public void invoke(PipelineData pipelineData, ValveContext context)

         throws IOException, TurbineException

     {

         RunData runData = pipelineData.getRunData();

         if (!runData.hasScreen())

         {

             String target = runData.getParameters().getString(URIConstants.CGI_SCREEN_PARAM);

             if (target != null)

             {

                 runData.setScreen(target);

                 log.debug("Set screen target from request parameter");

             }

             else

             {

                                 log.debug("No target screen");

             }

         }

         log.debug("Screen Target is now: {}", runData::getScreen);

         // Pass control to the next Valve in the Pipeline

         context.invokeNext(pipelineData);

     }

 }