Nuxt/docs/content/3.api/1.composables/use-async-data.md

useAsyncData

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

Type

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

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

type DataT = {
  data: Ref<DataT>
  pending: Ref<boolean>
  refresh: () => Promise<void>
  error: Ref<any>
}

Params

• key: a unique key to ensure that data fetching can be properly de-duplicated across requests
• handler: an asynchronous function that returns a value
• options:
  • lazy: whether to resolve the async function after loading the route, instead of blocking 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)
  • default: A function that returns the default value (before the handler function returns its value).

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: 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. Passing true as parameter skips that wait.

Example

const { data, pending, error, refresh } = useAsyncData(
  'mountains',
  () => $fetch('https://api.nuxtjs.dev/mountains),
  {
    pick: ['title']
  }
)

::ReadMore{link="/guide/features/data-fetching"} ::