How to react to Try region's Channel<Exception>?

vvvv gamma question
1

Hey hey,

Not sure if it’s a question or a bug :-)

Let’s say I have an Exception thrown in a Try region assigned to Create

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I would like to check if the type of the Exception is the one I’m looking for, and if so Log a message. My guess was to TryCast the exception to the concrete type, and if the cast works then Log the message.

But it looks like the first ForEach is never executed (the Counter does not increment).

Am I missing something? When getting the Value of the Channel, I can indeed see it’s an HttpListenerException inside!

Thanks!

CatchExceptionWithTry.vl (12.8 KB)

2

My guess: the exception is thrown before the downstream region is even connected. The region runs the inner patch straight away before the downstream connected foreach even had a chance to subscribe to the channel. I think the foreach region has a pin „Run at least once“ for that case, no?

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3

But watch out - you’ll have to add a null check then because for normal operation it will also run once with error channel containing null

4

Alright, using ForEach (Channel) did the trick, thanks @Elias !

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