Non-existent object in State

Dash Python
1

Hi all,
I think this problem isn’t new, but I just want to make sure that I haven’t missed anything or maybe there are new developments I didn’t know yet.

I have a quite complex app where multiple dash objects are created dynamically. I’d like to use them as State in a callback and need them only in cases where they have been created.
Essentially, I am already checking that this callback only runs through in scenarios where these elements exist already.
I already use the “prevent_initial_call=True” option, but I still receive this error from time to time. I think it heavily depends in which order some of the callbacks are executed.

Is there any way to solve this issue other than using a store for these parameters and defining this store in the global layout of the app such that it does exist and then fill this store at the time the elements are created?

Many thanks in advance and best wishes,
Julius

2

HI @xaver its difficult to answer to this quite generic question. It sounds as if pattern matching callbacks might mitigate the problems you encounter.

Is your app throwing errors or is it just a warning?

3

I already use pattern matching. And it is just showing as warning not as error, so it is not a big show-stopper. It would just be nice to work around these warnings.