org.omnifaces.exceptionhandler

Class ViewExpiredExceptionHandler

java.lang.Object

javax.faces.context.ExceptionHandler

javax.faces.context.ExceptionHandlerWrapper

org.omnifaces.exceptionhandler.ExceptionSuppressor

org.omnifaces.exceptionhandler.ViewExpiredExceptionHandler

All Implemented Interfaces:

EventListener, FacesListener, SystemEventListener, FacesWrapper<ExceptionHandler>

public class ViewExpiredExceptionHandler
extends ExceptionSuppressor

The ViewExpiredExceptionHandler will suppress any ViewExpiredException and refresh the current page by redirecting to the current URL with query string. Additionally, it will set a flash attribute indicating that the ViewExpiredException was handled by this exception handler.

Installation

This handler must be registered by a factory as follows in faces-config.xml in order to get it to run:

 <factory>
     <exception-handler-factory>org.omnifaces.exceptionhandler.ViewExpiredExceptionHandlerFactory</exception-handler-factory>
 </factory>
 

In case there are multiple exception handlers, best is to register this handler as last one in the chain. For example, when combined with FullAjaxExceptionHandler, this ordering will prevent the FullAjaxExceptionHandler from taking over the handling of the ViewExpiredException.

 <factory>
     <exception-handler-factory>org.omnifaces.exceptionhandler.FullAjaxExceptionHandlerFactory</exception-handler-factory>
     <exception-handler-factory>org.omnifaces.exceptionhandler.ViewExpiredExceptionHandlerFactory</exception-handler-factory>
 </factory>
 

Note

It's your own responsibility to make sure that the end user gets some form of feedback as to why exactly the page is refreshed and any submitted input values are lost. In order to check whether the previous request threw a ViewExpiredException which was handled by this exception handler, then you can use wasViewExpired() in managed beans and #{flash['org.omnifaces.view_expired'] eq true} in EL.

This approach will not work when the refresh in turn triggers yet another redirect elsewhere in the logic. In case you want to retain the condition for the next request, then you need to ensure that the involved logic explicitly triggers Flash.keep(String) in order to keep the flash attribute for the subsequent request. In the scope of OmniFaces, this is already taken care of by Faces.redirect(String, Object...) and derivates.

Since:

3.9

Author:

Lenny Primak

See Also:

ViewExpiredExceptionHandlerFactory

Field Summary

Fields

Modifier and Type	Field and Description
static String	FLASH_ATTRIBUTE_VIEW_EXPIRED The flash attribute name of a boolean value indicating that the previous request threw a ViewExpiredException which was handled by this exception handler.

Fields inherited from class org.omnifaces.exceptionhandler.ExceptionSuppressor

PARAM_NAME_EXCEPTION_TYPES_TO_SUPPRESS

Constructor Summary

Constructors

Constructor and Description
ViewExpiredExceptionHandler(ExceptionHandler wrapped) Construct a new view expired exception handler around the given wrapped exception handler.

Method Summary

Modifier and Type	Method and Description
protected void	handleSuppressedException(FacesContext context, Throwable suppressedException) Set the flash attribute "org.omnifaces.view_expired".
static boolean	wasViewExpired() Returns true if the previous request threw a ViewExpiredException which was handled by this exception handler.

Methods inherited from class org.omnifaces.exceptionhandler.ExceptionSuppressor

getExceptionTypesToSuppress, handle

Methods inherited from class javax.faces.context.ExceptionHandlerWrapper

getHandledExceptionQueuedEvent, getHandledExceptionQueuedEvents, getRootCause, getUnhandledExceptionQueuedEvents, getWrapped, isListenerForSource, processEvent

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Field Detail

FLASH_ATTRIBUTE_VIEW_EXPIRED

public static final String FLASH_ATTRIBUTE_VIEW_EXPIRED

The flash attribute name of a boolean value indicating that the previous request threw a ViewExpiredException which was handled by this exception handler.

See Also:

Constant Field Values

Constructor Detail

ViewExpiredExceptionHandler

public ViewExpiredExceptionHandler(ExceptionHandler wrapped)

Construct a new view expired exception handler around the given wrapped exception handler.

Parameters:

wrapped - The wrapped exception handler.

Method Detail

handleSuppressedException

protected void handleSuppressedException(FacesContext context,
                                         Throwable suppressedException)

Set the flash attribute "org.omnifaces.view_expired".

Overrides:

handleSuppressedException in class ExceptionSuppressor

Parameters:

context - The involved faces context.

suppressedException - The suppressed exception.

wasViewExpired

public static boolean wasViewExpired()

Returns true if the previous request threw a ViewExpiredException which was handled by this exception handler.

Returns:

true if the previous request threw a ViewExpiredException which was handled by this exception handler.