Query

This is the Jotai integration with TanStack Query v4, a set of hooks and tools for managing async state (typically external data).

From the Overview docs:

React Query is often described as the missing data-fetching library for React, but in more technical terms, it makes fetching, caching, synchronizing and updating server state in your React applications a breeze.

Jotai with TanStack Query provides a wonderful interface with all of the TanStack Query features, providing you the ability to use those features in combination with your existing Jotai state.

Install

In addition to jotai, you have to install @tanstack/query-core to make use of this bundle and its functions.

yarn add @tanstack/query-core

atomWithQuery

atomWithQuery creates a new atom that implements a standard Query from TanStack Query. This function combines both Jotai atom features and useQuery features in a single atom. This atom supports all features you'd expect to find when using the standard @tanstack/react-query package.

A query is a declarative dependency on an asynchronous source of data that is tied to a unique key. A query can be used with any Promise based method (including GET and POST methods) to fetch data from a server.

import { useAtom } from 'jotai'
import { atomWithQuery } from 'jotai/query'

const idAtom = atom(1)
const userAtom = atomWithQuery((get) => ({
  queryKey: ['users', get(idAtom)],
  queryFn: async ({ queryKey: [, id] }) => {
    const res = await fetch(`https://jsonplaceholder.typicode.com/users/${id}`)
    return res.json()
  },
}))

const UserData = () => {
  const [data] = useAtom(userAtom)
  return <div>{JSON.stringify(data)}</div>
}

atomWithInfiniteQuery

atomWithInfiniteQuery is very similar to atomWithQuery, however it creates an InfiniteQuery, which is used for data that is meant to be paginated. You can read more about Infinite Queries here. This atom supports all features you'd expect to find when using the standard @tanstack/react-query package.

Rendering lists that can additively "load more" data onto an existing set of data or "infinite scroll" is also a very common UI pattern. React Query supports a useful version of useQuery called useInfiniteQuery for querying these types of lists.

A notable difference between a standard query atom is the additional option getNextPageParam and getPreviousPageParam, which is what you'll use to instruct the query on how to fetch any additional pages.

import { useAtom } from 'jotai'
import { atomWithInfiniteQuery } from 'jotai/query'

const idAtom = atom(1)
const userAtom = atomWithInfiniteQuery((get) => ({
  queryKey: ['users', get(idAtom)],
  queryFn: async ({ queryKey: [, id] }) => {
    const res = await fetch(`https://jsonplaceholder.typicode.com/users/${id}`)
    return res.json()
  },
  // infinite queries can support paginated fetching
  getNextPageParam: (lastPage, pages) => lastPage.nextCursor,
}))

const UserData = () => {
  const [data] = useAtom(userAtom)
  return data.pages.map((userData, index) => (
    <div key={index}>{JSON.stringify(userData)}</div>
  ))
}

Fetching pages and refetching

Using the same atom as in the above example, we can use the update method returned from useAtom to call different @tanstack/react-query methods:

const UserData = () => {
  const [data, update] = useAtom(userAtom)

  const handleFetchNextPage = () => update({ type: 'fetchNextPage' })

  const handleFetchPreviousPage = () => update({ type: 'fetchPreviousPage' })

  const handleRefetchAllPages = () => update({ type: 'refetch' })
}

Referencing the same instance of Query Client in your project

Perhaps you have some custom hooks in your project that utilises the useQueryClient() hook to obtain the QueryClient object and call its methods.

To ensure that you reference the same QueryClient object, be sure to wrap the root of your project in a <Provider> and initialise queryClientAtom with the same queryClient value you provided to QueryClientProvider.

Without this step, useQueryAtom will reference a seperate QueryClient from any hooks that utilise the useQueryClient() hook to get the queryClient.

Example

In the example below, we have a mutation hook, useTodoMutation and a query todosAtom.

We included an initialisation step in our root <App> node.

Although they reference methods same query key ('todos'), the onSuccess invalidation in useTodoMutation will not trigger if the Provider initialisation step was not done.

This will result in todosAtom showing stale data as it was not prompted to refetch.

import {
  useMutation,
  useQueryClient,
  QueryClient,
  QueryClientProvider,
} from '@tanstack/react-query'
import { atomWithQuery } from 'jotai/query'

const queryClient = new QueryClient()
export const App = () => {
  return (
    <QueryClientProvider client={queryClient}>
      {/* This Provider initalization step is needed so that we reference the same
      queryClient in both atomWithQuery and other parts of the app. Without this,
      our useQueryClient() hook will return a different QueryClient object */}
      <Provider initialValues={[[queryClientAtom, queryClient]]}>
        <App />
      </Provider>
    </QueryClientProvider>
  )
}

export const todosAtom = atomWithQuery((get) => {
  return {
    queryKey: ['todos'],
    queryFn: () => fetch('/todos'),
  }
})

export const useTodoMutation = () => {
  const queryClient = useQueryClient()

  return useMutation(
    async (body: todo) => {
      await fetch('/todo', { Method: 'POST', Body: body })
    },
    {
      onSuccess: () => {
        void queryClient.invalidateQueries(['todos'])
      },
      onError,
    }
  )
}

SSR support

Both atoms can be used within the context of a server side rendered app, such as a next.js app or Gatsby app. You can use both options that React Query supports for use within SSR apps, hydration or initialData.

Error handling

Fetch error will be thrown and can be caught with ErrorBoundary. Refetching may recover from a temporary error.

See a working example to learn more.

Examples

Basic demo

Hackernews