useAsyncData

Within your pages, components, and plugins you can use useAsyncData to get access to data that resolves asynchronously.

Type

Signature
function useAsyncData(
  handler: (nuxtApp?: NuxtApp) => Promise<DataT>,
  options?: AsyncDataOptions<DataT>
): AsyncData<DataT>
function useAsyncData(
  key: string,
  handler: (nuxtApp?: NuxtApp) => Promise<DataT>,
  options?: AsyncDataOptions<DataT>
): Promise<AsyncData<DataT>>

type AsyncDataOptions<DataT> = {
  server?: boolean
  lazy?: boolean
  default?: () => DataT | Ref<DataT> | null
  transform?: (input: DataT) => DataT
  pick?: string[]
  watch?: WatchSource[]
  initialCache?: boolean
  immediate?: boolean
}

interface RefreshOptions {
  _initial?: boolean
}

type AsyncData<DataT, ErrorT> = {
  data: Ref<DataT | null>
  pending: Ref<boolean>
  execute: () => Promise<void>
  refresh: (opts?: RefreshOptions) => Promise<void>
  error: Ref<ErrorT | null>
}


Params

  • key: a unique key to ensure that data fetching can be properly de-duplicated across requests. If you do not provide a key, then a key that is unique to the file name and line number of the instance of useAsyncData will be generated for you.
  • handler: an asynchronous function that returns a value
  • options:
    • lazy: whether to resolve the async function after loading the route, instead of blocking client-side navigation (defaults to false)
    • default: a factory function to set the default value of the data, before the async function resolves - particularly useful with the lazy: true option
    • server: whether to fetch the data on the server (defaults to true)
    • transform: a function that can be used to alter handler function result after resolving
    • pick: only pick specified keys in this array from the handler function result
    • watch: watch reactive sources to auto-refresh
    • initialCache: When set to false, will skip payload cache for initial fetch. (defaults to true)
    • immediate: When set to false, will prevent the request from firing immediately. (defaults to true)

Under the hood, lazy: false uses <Suspense> to block the loading of the route before the data has been fetched. Consider using lazy: true and implementing a loading state instead for a snappier user experience.

Return Values

  • data: the result of the asynchronous function that is passed in
  • pending: a boolean indicating whether the data is still being fetched
  • refresh/execute: a function that can be used to refresh the data returned by the handler function
  • error: an error object if the data fetching failed

By default, Nuxt waits until a refresh is finished before it can be executed again.

If you have not fetched data on the server (for example, with server: false), then the data will not be fetched until hydration completes. This means even if you await useAsyncData on the client side, data will remain null within <script setup>.

Example

const { data, pending, error, refresh } = await useAsyncData(
  'mountains',
  () => $fetch('https://api.nuxtjs.dev/mountains')
)
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Edit this page on GitHub Updated at Mon, Oct 3, 2022