mirror of
https://github.com/nuxt/nuxt.git
synced 2024-11-24 22:55:13 +00:00
89 lines
3.3 KiB
Markdown
89 lines
3.3 KiB
Markdown
---
|
|
description: useAsyncData provides access to data that resolves asynchronously.
|
|
---
|
|
# `useAsyncData`
|
|
|
|
Within your pages, components, and plugins you can use useAsyncData to get access to data that resolves asynchronously.
|
|
|
|
## Type
|
|
|
|
```ts [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[]
|
|
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 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.
|
|
|
|
::alert{type=warning}
|
|
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
|
|
|
|
```ts
|
|
const { data, pending, error, refresh } = await useAsyncData(
|
|
'mountains',
|
|
() => $fetch('https://api.nuxtjs.dev/mountains')
|
|
)
|
|
```
|
|
|
|
::alert{type=warning}
|
|
`useAsyncData` is a reserved function name transformed by the compiler, so you should not name your own function `useAsyncData`.
|
|
::
|
|
|
|
::ReadMore{link="/docs/getting-started/data-fetching"}
|
|
::
|