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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.