[TYPO3-mvc] Flash Messages get persisted among page hits

[Franz Koch]

Hey,

>> If you add a flash message and then do an external redirect, it has to
>> be stored in the session until the next request. That is what's
>> happening in the dispatcher.
>
> Why? If you leave the page the semantic context of the message will be lost.

right, I also don't see a reason for this. Even if I would do a redirect 
to something like a "order confimration" page in a shop extension, I 
don't necessarily need to display a session stored flash message telling 
me "thanks, your order has been placed..." as there for sure will be a 
dedicated template for this using some L10N translations. So for me a 
flash message is and will always only be vaild for the current page/request.

>> b) If a flash message is rendered, the cache of this page (well, the
>> cache for this cHash would be enough) must be invalidated; to only cache
>> outputs without flash-messages. Any suggestions how to clear that cache
>> for a single cHash? I'm not that good concerning the caching framework ;)

If there is a flash message, there's most likely also some form/data 
submission (thus dynamic content) that's requiring that the extension is 
USER_INT anyway.

-- 
kind regards,
Franz Koch