/*

  * 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.

  */

 package org.apache.myfaces.shared.context;

 import javax.faces.context.ExceptionHandler;

 import javax.faces.context.ExceptionHandlerWrapper;

 import javax.faces.context.FacesContext;

 import javax.faces.context.PartialViewContext;

 import javax.faces.event.AbortProcessingException;

 import javax.faces.event.ExceptionQueuedEvent;

 import javax.faces.event.ExceptionQueuedEventContext;

 import javax.faces.event.SystemEvent;

 /**

  * This wrapper is a switch to choose in a lazy way between ajax and

  * normal exceptionHandler wrapping, because FacesContext is initialized after

  * ExceptionHandler, so it is not safe to get it when

  * ExceptionHandlerFactory.getExceptionHandler() is called.

  */

 public class SwitchAjaxExceptionHandlerWrapperImpl extends ExceptionHandlerWrapper

 {

     private ExceptionHandler _requestExceptionHandler;

     private ExceptionHandler _ajaxExceptionHandler;

     private Boolean _isAjaxRequest;

     public SwitchAjaxExceptionHandlerWrapperImpl(

             ExceptionHandler requestExceptionHandler,

             ExceptionHandler ajaxExceptionHandler)

     {

         _requestExceptionHandler = requestExceptionHandler;

         _ajaxExceptionHandler = ajaxExceptionHandler;

     }

     @Override

     public void processEvent(SystemEvent exceptionQueuedEvent)

             throws AbortProcessingException

     {

         //Check if this is an ajax request, but take advantage of exceptionQueuedEvent facesContext

         isAjaxRequest(exceptionQueuedEvent);

         super.processEvent(exceptionQueuedEvent);

     }

     protected boolean isAjaxRequest(SystemEvent exceptionQueuedEvent)

     {

         if (_isAjaxRequest == null)

         {

             if (exceptionQueuedEvent instanceof ExceptionQueuedEvent)

             {

                 ExceptionQueuedEvent eqe = (ExceptionQueuedEvent)exceptionQueuedEvent;

                 ExceptionQueuedEventContext eqec = eqe.getContext();

                 if (eqec != null)

                 {

                     FacesContext facesContext = eqec.getContext();

                     if (facesContext != null)

                     {

                         return isAjaxRequest(facesContext);

                     }

                 }

             }

             return isAjaxRequest();

         }

         return _isAjaxRequest;

     }

     protected boolean isAjaxRequest(FacesContext facesContext)

     {

         if (_isAjaxRequest == null)

         {

             facesContext = (facesContext == null) ? FacesContext.getCurrentInstance() : facesContext;

             PartialViewContext pvc = facesContext.getPartialViewContext();

             if (pvc == null)

             {

                 return false;

             }

             _isAjaxRequest = pvc.isAjaxRequest();

         }

         return _isAjaxRequest;

     }

     protected boolean isAjaxRequest()

     {

         if (_isAjaxRequest == null)

         {

             FacesContext facesContext = FacesContext.getCurrentInstance();

             PartialViewContext pvc = facesContext.getPartialViewContext();

             if (pvc == null)

             {

                 return false;

             }

             _isAjaxRequest = pvc.isAjaxRequest();

         }

         return _isAjaxRequest;

     }

     @Override

     public ExceptionHandler getWrapped()

     {

         if (isAjaxRequest())

         {

             return _ajaxExceptionHandler;

         }

         else

         {

             return _requestExceptionHandler;

         }

     }

 }