Any way to check a prop or path in a proxy is subscribed?

[pilaoda]

I am working on a Replication system.

Here is the workflow.

1. it recieved serialized object from network.
2. deserialize object, then set it into a big valtio proxy by "UID", state["UID"] = deserializedObj.
3. trigger re-render for those component call useSnapshot(state)["UID"].

If there is a api IsPathSubscribed(state, "UID"), then I can skip step 2 deserialization for those object not subscribed.
Client may receive thousands of serialized objects, but only one of them need to be deserialized for react to show.

[dai-shi]

Valtio doesn't provide a direct solution to it (not possible by design), but wouldn't you be able to create a custom hook to track the usage?

useMySnapshot(state, "UID")

[pilaoda]

OK, I will try it.

[overthemike]

As Dai-shi said, valtio doesn't support this because it uses references rather than tracking by path. Are you just wanting to see if an object has the same shape as one that came before it?

[pilaoda]

No, I just want to skip some unnecessary deserialization and write on state proxy.

[overthemike]

Ok - how are you wanting to determine whether or not you need to deserialize it?

[pilaoda]

Ok - how are you wanting to determine whether or not you need to deserialize it?

if that object is used by react component through useSnapshot and access by its UID, then it should be deserialized.

[overthemike]

Hm - well if it's easy enough to track it through your own means in your own hook like suggested earlier, go with that. There might be a way to access what you need within valtio's own snapshot cache and by checking the version number out. You'd have to play around with it though to see if it would give you what you're wanting.

import { unstable_getInternalState, getVersion } from 'valtio'
const { snapCache } = unstable_getInternalStates()