persist API: store initial value

Hey guys, first of all, I really like the library! I’d like to extend the PersistOptions API to fit my needs. I’ll briefly introduce my use case: I want to set the unique id to the client device, smth like this:

create(persist((() => ({
  id: guuid(),
  ...
}), { name: localStorageKey }));

Every time I refresh the page, the id changes. I’d love to have that state value saved to the localStorage at the time of a new store creation. I’m aware I can declare extra action that sets the id explicitly, but I think an extra property to PersistOptions, smth like { storeInitialValue: boolean } (store only when localStorage.name does not exists) would be a much cleaner solution. And of course, maybe I’m missing something, but I’d love to hear your feedback on this.

[TheEhsanSarshar]

Ok, I got it.

• async await
• DX

[dai-shi]

@dai-shi we can have { presistedFields: [ "fieldname" ] } inside persistoptions object. if you will I can work on this.

I don’t think it’s that easy. We also need to take care of AsyncStorage.

(beware, however, that this currently happens asynchronously: #346).

https://github.com/pmndrs/zustand/issues/346#issuecomment-810342287 We should fix this, and then localStorage users can store initial values before calling create(). You want to work on this? hint: https://github.com/pmndrs/jotai/blob/8e1366af11251e3873b9fddde5ffd011a469d95c/src/utils/atomWithStorage.ts#L39-L42