useAsyncData
Within your pages, components, and plugins you can use useAsyncData to get access to data that resolves asynchronously.
Type
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[] immediate?: boolean}interface RefreshOptions { dedupe?: 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
- immediate: When set to
false
, will prevent the request from firing immediately. (defaults totrue
)
- lazy: whether to resolve the async function after loading the route, instead of blocking client-side navigation (defaults to
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'))
useAsyncData
is a reserved function name transformed by the compiler, so you should not name your own function useAsyncData
.