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.commons.logging.Log;

 import org.apache.commons.logging.LogFactory;

 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 'action' property of RunData based

  * on request parameter. There is no default action, since a null action is

  * perfectly valid.

  *

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

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

  */

 public class DetermineActionValve

     extends AbstractValve

 {

     private static final Log log

         = LogFactory.getLog(DetermineActionValve.class);

     /**

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

      */

     public void invoke(PipelineData pipelineData, ValveContext context)

         throws IOException, TurbineException

     {

         RunData data = getRunData(pipelineData);

         if (! data.hasAction())

         {

             String action =

                 data.getParameters().getString(URIConstants.CGI_ACTION_PARAM);

             if (action != null)

             {

                 data.setAction(action);

                 log.debug("Set action from request parameter");

             }

             else

             {

                 log.debug("No action");

             }

         }

         if (log.isDebugEnabled())

         {

             log.debug("Action is now: " + data.getAction());

         }

         // Pass control to the next Valve in the Pipeline

         context.invokeNext(pipelineData);

     }

 }