Is it possible to get the implicit store?

[matthew-dean]

Still more store questions, sorry!

Today's question. So, I understand that you an do createStore() (currently unstable_createStore) and my understanding is that you can set that store for the tree using <Provider>.

My question is, for provider-less mode, is it possible to just "get" that "provider-less" store? Like the implicit store that Jotai will create? Such that I don't have to require the use of <Provider> for an end-user where I am using a Jotai store to get/set values in utility functions?

Something like:

import { getStore, atom } from 'jotai'

const atomWhoseValueHasBeenSetByAComponent = atom(0)
const store = getStore()

// ...later, after my React tree has done things...
const foo = store.get(atomWhoseValueHasBeenSetByAComponent)

[dai-shi]

You are welcome to have many questions.
The default store for provider less mode is hidden. It's technically possible to expose it, but that's why provider is provided to replace the default store. Isn't it too much trouble to put one provider component at your root of the tree?

[matthew-dean]

To be clear, I would re-write this as:

import { getDefaultStore, useAtom } from 'jotai'
import { atomWithStorage } from 'jotai/utils'

const store = getDefaultStore()

export const featureFlagsAtom = atomWithStorage<LDFlagSet>('featureFlags', {})

/**
 * We can use `useAtom`!
 */
export const useFeatureFlags = () => {
  const [flags] = useAtom(featureFlagsAtom)
  return flags
}

export const setupFeatureFlags = (clientId: string, user?: LDUser) => {
  const client = LDClient.initialize(clientId, user ?? { anonymous: true }, {
    sendEventsOnlyForVariation: true
  })
  client.on('initialized', () => {
    store.set(featureFlagsAtom, client.allFlags())
  })
  client.on('change', () => {
    store.set(featureFlagsAtom, client.allFlags())
  })
  return { client }
}

[matthew-dean]

One thing to clarify and may make this easier to understand -- This is a code contract between two teams. One building shared components and utilities, and another building apps. It's an easier contract if the app team is not forced to add things to their tree and can just import / use utilities and hooks as-is. It's not the end of the world if they had to add a Provider; we would just prefer it wasn't necessary, and that it we wouldn't add Provider bloat to each app.

[dai-shi]

Notice useAtom is contextual. I don't think exposing default store solves your issue completely. It can access to a different store.

To mitigate misusing a different store, what I can think of is to add a special atom and check its value in advance in a custom hook.

[matthew-dean]

@dai-shi

Notice useAtom is contextual. I don't think exposing default store solves your issue completely.

I get that it's contextual. My point is that if I could get the default store, I would only use that store, which means all functions would use that as the store context without an explicit <Provider>. I wouldn't use createStore().

[dai-shi]

But, your teammates can break the rule and use Provide somewhere, right? It then doesn't read from the default store.