req: derivate children snapshot

[DavideSegullo]

Hi guys, I'm trying to use jotai-xstate to derivate children actor snapshot, the context is that I have a parent state machine, which based on conditions spaws children, I would like to be able to access the snapshot of these children (when spawned) to be able to determine the substates of the children, is this already possible using atomWithActorSnapshot?

I assume not because if the actor used as input changes, a new subscription is not created. Maybe we only need a way to detect input atom changes and then subscribe again

If someone can give me some suggestions I can also try to do a PR myself, thank you!

For example using react is possible to use useSelector with empty actor if it's undefined: https://stately.ai/docs/actors#empty-actors

[dai-shi]

@brunocangs thoughts?

[brunocangs]

I've never coded anything that spawns children before so not sure. Could you provide a basic example and point where it breaks? Maybe we can come up with an idea

Edit: typo

[DavideSegullo]

I've never coded anything that spawns children before so not sure. Could you provide a basic example and point where it breaks? Maybe we can come up with an idea

Edit: typo

Ye ofc, I'll send you and example today when I'll get back home, thank you!

[DavideSegullo]

@brunocangs Here a link I also added some comments inside the code, let me know if it makes sense for you! Thank you

https://stackblitz.com/edit/vitejs-vite-rd4cpznr?file=src%2FApp.tsx

[brunocangs]

Thanks! I'll take a look and play around and get back to you in a few hours

[brunocangs]

@DavideSegullo It seems that a quick fix allowing the atom to handle undefined is enough to cover the case you showed on the stackblitz. Could you check the PR/branch to see if it fixes the problem? I tested it with the example you provided and it seemed to work well. Do you have any other cases this change might not cover?

Edit: added second image

[DavideSegullo]

@DavideSegullo It seems that a quick fix allowing the atom to handle undefined is enough to cover the case you showed on the stackblitz. Could you check the PR/branch to see if it fixes the problem? I tested it with the example you provided and it seemed to work well. Do you have any other cases this change might not cover?

Edit: added second image

It looks good, I tried it locally by patching jotai-xstate package, I only get this ts error:

[DavideSegullo]

So actually we can suppress this error by casting snapshot.children.getUser to AnyActor