🤖 Powerful asynchronous state management, server-state utilities and data fetching for the web. TS/JS, React Query, Solid Query, Svelte Query and Vue Query.
> Note: This util is also included in the `@tanstack/react-query-persist-client` package, so you do not need to install it separately if you are using that package.
## Usage
- Import the `experimental_createPersister` function
- Create a new `experimental_createPersister`
- you can pass any `storage` to it that adheres to the `AsyncStorage` or `Storage` interface - the example below uses the async-storage from React Native.
- Pass that `persister` as an option to your Query. This can be done either by passing it to the `defaultOptions` of the `QueryClient` or to any `useQuery` hook instance.
- If you pass this `persister` as `defaultOptions`, all queries will be persisted to the provided `storage`. You can additionally narrow this down by passing `filters`. In contrast to the `persistClient` plugin, this will not persist the whole query client as a single item, but each query separately. As a key, the query hash is used.
- If you provide this `persister` to a single `useQuery` hook, only this Query will be persisted.
This way, you do not need to store whole `QueryClient`, but choose what is worth to be persisted in your application. Each query is lazily restored (when the Query is first used) and persisted (after each run of the `queryFn`), so it does not need to be throttled. `staleTime` is also respected after restoring the Query, so if data is considered `stale`, it will be refetched immediately after restoring. If data is `fresh`, the `queryFn` will not run.
Garbage collecting a Query from memory **does not** affect the persisted data. That means Queries can be kept in memory for a shorter period of time to be more **memory efficient**. If they are used the next time, they will just be restored from the persistent storage again.
The `createPersister` plugin technically wraps the `queryFn`, so it doesn't restore if the `queryFn` doesn't run. In that way, it acts as a caching layer between the Query and the network. Thus, the `networkMode` defaults to `'offlineFirst'` when a persister is used, so that restoring from the persistent storage can also happen even if there is no network connection.
