Is there an universal way to retrive the value of an atom without using useAtom?

Is there an equivalent way of fetching an atom’s value as in zustand using someStore.getState()? I’m currently having some issues to get this to work:

type IdToPathMap = { [key: string]: string }
const idToPathMapAtom = atom<IdToPathMap>({})

type Element = { id: string, payload: any, children: Element[] }
const elementsAtom = atom<Element>([])

export const elementAtomFamily = atomFamily(
  (id) => {
    // How to get the path here?
   const path = idToPathMap[id];
    return focusAtom(elementsAtom, (optic) => optic.path(path))
  },
  isEqual,
);

Or is it better to provide a getter function in the second parameter, so’d be something like this?

return focusAtom(elementsAtom, (optic, get) => optic.path(get(idToPathMapAtom)[id]))

Another use case is that sometimes I need to retrive the data of an atom in an event handler, without causing rerender when the data changes.

[dai-shi]

Closing as answered. You or anyone can add some more comments, but would be nice to open new issue/discussions for new questions.

[dai-shi]

Thanks for your reply.

  const path = useAtom(useMemo(() => atom((get) => get(idToPathMapAtom)[id])), [id]))

In this case let’s say idToPathMapAtom got updated, since it’s cached based on id, will it trigger an update? If not path would be stale then.

With this, it will re-evaluate when idPathMapAtom changes and only trigger re-render if path changes.

With getAtom, it may not trigger re-render when idPathMapAtom changes. At least not guaranteed.

Or should it be more like this?

  const idToPathMap = useAtomValue(idToPathMapAtom)
  const path = useAtom(useMemo(() => atom((get) => idToPathMapAtom[id])), [id, idToPathMap]))

With this, it will re-render every time idToPathMap is changed, regardless of the case if path isn’t changed. So, it’s not something you want.

But with this approach, when idToPathMap changes very fraquently, the cache might keep growing, it won’t cause a huge problem I guess, but it could cause small memory leaks. I’d still prefer there is a better approach, if there is any

Oh, by the way, we take the memory leak issue seriously. We want to fully support these use cases. Implementation-wise, atom values are stored in WeakMaps, so it should be garbage collected. garbage collection is not free though. If you want more control in caching, you can try atomFamily or your own cache.