mirror of
https://github.com/nuxt/nuxt.git
synced 2024-12-05 03:47:12 +00:00
189 lines
9.2 KiB
Markdown
189 lines
9.2 KiB
Markdown
---
|
|
title: 'useFetch'
|
|
description: 'Fetch data from an API endpoint with an SSR-friendly composable.'
|
|
links:
|
|
- label: Source
|
|
icon: i-simple-icons-github
|
|
to: https://github.com/nuxt/nuxt/blob/main/packages/nuxt/src/app/composables/fetch.ts
|
|
size: xs
|
|
---
|
|
|
|
This composable provides a convenient wrapper around [`useAsyncData`](/docs/api/composables/use-async-data) and [`$fetch`](/docs/api/utils/dollarfetch).
|
|
It automatically generates a key based on URL and fetch options, provides type hints for request url based on server routes, and infers API response type.
|
|
|
|
::note
|
|
`useFetch` is a composable meant to be called directly in a setup function, plugin, or route middleware. It returns reactive composables and handles adding responses to the Nuxt payload so they can be passed from server to client without re-fetching the data on client side when the page hydrates.
|
|
::
|
|
|
|
## Usage
|
|
|
|
```vue [pages/modules.vue]
|
|
<script setup lang="ts">
|
|
const { data, status, error, refresh, clear } = await useFetch('/api/modules', {
|
|
pick: ['title']
|
|
})
|
|
</script>
|
|
```
|
|
|
|
::warning
|
|
If you're using a custom useFetch wrapper, do not await it in the composable, as that can cause unexpected behavior. Please follow [this recipe](/docs/guide/recipes/custom-usefetch#custom-usefetch) for more information on how to make a custom async data fetcher.
|
|
::
|
|
|
|
::note
|
|
`data`, `status`, and `error` are Vue refs, and they should be accessed with `.value` when used within the `<script setup>`, while `refresh`/`execute` and `clear` are plain functions.
|
|
::
|
|
|
|
Using the `query` option, you can add search parameters to your query. This option is extended from [unjs/ofetch](https://github.com/unjs/ofetch) and is using [unjs/ufo](https://github.com/unjs/ufo) to create the URL. Objects are automatically stringified.
|
|
|
|
```ts
|
|
const param1 = ref('value1')
|
|
const { data, status, error, refresh } = await useFetch('/api/modules', {
|
|
query: { param1, param2: 'value2' }
|
|
})
|
|
```
|
|
|
|
The above example results in `https://api.nuxt.com/modules?param1=value1¶m2=value2`.
|
|
|
|
You can also use [interceptors](https://github.com/unjs/ofetch#%EF%B8%8F-interceptors):
|
|
|
|
```ts
|
|
const { data, status, error, refresh, clear } = await useFetch('/api/auth/login', {
|
|
onRequest({ request, options }) {
|
|
// Set the request headers
|
|
// note that this relies on ofetch >= 1.4.0 - you may need to refresh your lockfile
|
|
options.headers.set('Authorization', '...')
|
|
},
|
|
onRequestError({ request, options, error }) {
|
|
// Handle the request errors
|
|
},
|
|
onResponse({ request, response, options }) {
|
|
// Process the response data
|
|
localStorage.setItem('token', response._data.token)
|
|
},
|
|
onResponseError({ request, response, options }) {
|
|
// Handle the response errors
|
|
}
|
|
})
|
|
```
|
|
|
|
::warning
|
|
`useFetch` is a reserved function name transformed by the compiler, so you should not name your own function `useFetch`.
|
|
::
|
|
|
|
::warning
|
|
If you encounter the `data` variable destructured from a `useFetch` returns a string and not a JSON parsed object then make sure your component doesn't include an import statement like `import { useFetch } from '@vueuse/core`.
|
|
::
|
|
|
|
::tip{icon="i-ph-video" to="https://www.youtube.com/watch?v=njsGVmcWviY" target="_blank"}
|
|
Watch the video from Alexander Lichter to avoid using `useFetch` the wrong way!
|
|
::
|
|
|
|
:link-example{to="/docs/examples/advanced/use-custom-fetch-composable"}
|
|
|
|
:read-more{to="/docs/getting-started/data-fetching"}
|
|
|
|
:link-example{to="/docs/examples/features/data-fetching"}
|
|
|
|
## Params
|
|
|
|
- `URL`: The URL to fetch.
|
|
- `Options` (extends [unjs/ofetch](https://github.com/unjs/ofetch) options & [AsyncDataOptions](/docs/api/composables/use-async-data#params)):
|
|
- `method`: Request method.
|
|
- `query`: Adds query search params to URL using [ufo](https://github.com/unjs/ufo)
|
|
- `params`: Alias for `query`
|
|
- `body`: Request body - automatically stringified (if an object is passed).
|
|
- `headers`: Request headers.
|
|
- `baseURL`: Base URL for the request.
|
|
- `timeout`: Milliseconds to automatically abort request
|
|
- `cache`: Handles cache control according to [Fetch API](https://developer.mozilla.org/en-US/docs/Web/API/fetch#cache)
|
|
- You can pass boolean to disable the cache or you can pass one of the following values: `default`, `no-store`, `reload`, `no-cache`, `force-cache`, and `only-if-cached`.
|
|
|
|
::note
|
|
All fetch options can be given a `computed` or `ref` value. These will be watched and new requests made automatically with any new values if they are updated.
|
|
::
|
|
|
|
- `Options` (from [`useAsyncData`](/docs/api/composables/use-async-data)):
|
|
- `key`: a unique key to ensure that data fetching can be properly de-duplicated across requests, if not provided, it will be automatically generated based on URL and fetch options
|
|
- `server`: whether to fetch the data on the server (defaults to `true`)
|
|
- `lazy`: whether to resolve the async function after loading the route, instead of blocking client-side navigation (defaults to `false`)
|
|
- `immediate`: when set to `false`, will prevent the request from firing immediately. (defaults to `true`)
|
|
- `default`: a factory function to set the default value of the `data`, before the async function resolves - useful with the `lazy: true` or `immediate: false` option
|
|
- `transform`: a function that can be used to alter `handler` function result after resolving
|
|
- `getCachedData`: Provide a function which returns cached data. A _null_ or _undefined_ return value will trigger a fetch. By default, this is: `key => nuxt.isHydrating ? nuxt.payload.data[key] : nuxt.static.data[key]`, which only caches data when `payloadExtraction` is enabled.
|
|
- `pick`: only pick specified keys in this array from the `handler` function result
|
|
- `watch`: watch an array of reactive sources and auto-refresh the fetch result when they change. Fetch options and URL are watched by default. You can completely ignore reactive sources by using `watch: false`. Together with `immediate: false`, this allows for a fully-manual `useFetch`. (You can [see an example here](/docs/getting-started/data-fetching#watch) of using `watch`.)
|
|
- `deep`: return data in a deep ref object (it is `true` by default). It can be set to `false` to return data in a shallow ref object, which can improve performance if your data does not need to be deeply reactive.
|
|
- `dedupe`: avoid fetching same key more than once at a time (defaults to `cancel`). Possible options:
|
|
- `cancel` - cancels existing requests when a new one is made
|
|
- `defer` - does not make new requests at all if there is a pending request
|
|
|
|
::note
|
|
If you provide a function or ref as the `url` parameter, or if you provide functions as arguments to the `options` parameter, then the `useFetch` call will not match other `useFetch` calls elsewhere in your codebase, even if the options seem to be identical. If you wish to force a match, you may provide your own key in `options`.
|
|
::
|
|
|
|
::note
|
|
If you use `useFetch` to call an (external) HTTPS URL with a self-signed certificate in development, you will need to set `NODE_TLS_REJECT_UNAUTHORIZED=0` in your environment.
|
|
::
|
|
|
|
::tip{icon="i-simple-icons-youtube" color="gray" to="https://www.youtube.com/watch?v=aQPR0xn-MMk" target="_blank"}
|
|
Learn how to use `transform` and `getCachedData` to avoid superfluous calls to an API and cache data for visitors on the client.
|
|
::
|
|
|
|
## Return Values
|
|
|
|
- `data`: the result of the asynchronous function that is passed in.
|
|
- `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.
|
|
- `status`: a string indicating the status of the data request (`"idle"`, `"pending"`, `"success"`, `"error"`).
|
|
- `clear`: a function which will set `data` to `undefined`, set `error` to `null`, set `status` to `'idle'`, and mark any currently pending requests as cancelled.
|
|
|
|
By default, Nuxt waits until a `refresh` is finished before it can be executed again.
|
|
|
|
::note
|
|
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 `useFetch` on client-side, `data` will remain null within `<script setup>`.
|
|
::
|
|
|
|
## Type
|
|
|
|
```ts [Signature]
|
|
function useFetch<DataT, ErrorT>(
|
|
url: string | Request | Ref<string | Request> | (() => string) | Request,
|
|
options?: UseFetchOptions<DataT>
|
|
): Promise<AsyncData<DataT, ErrorT>>
|
|
|
|
type UseFetchOptions<DataT> = {
|
|
key?: string
|
|
method?: string
|
|
query?: SearchParams
|
|
params?: SearchParams
|
|
body?: RequestInit['body'] | Record<string, any>
|
|
headers?: Record<string, string> | [key: string, value: string][] | Headers
|
|
baseURL?: string
|
|
server?: boolean
|
|
lazy?: boolean
|
|
immediate?: boolean
|
|
getCachedData?: (key: string, nuxtApp: NuxtApp) => DataT
|
|
deep?: boolean
|
|
dedupe?: 'cancel' | 'defer'
|
|
default?: () => DataT
|
|
transform?: (input: DataT) => DataT | Promise<DataT>
|
|
pick?: string[]
|
|
watch?: WatchSource[] | false
|
|
}
|
|
|
|
type AsyncData<DataT, ErrorT> = {
|
|
data: Ref<DataT | null>
|
|
refresh: (opts?: AsyncDataExecuteOptions) => Promise<void>
|
|
execute: (opts?: AsyncDataExecuteOptions) => Promise<void>
|
|
clear: () => void
|
|
error: Ref<ErrorT | null>
|
|
status: Ref<AsyncDataRequestStatus>
|
|
}
|
|
|
|
interface AsyncDataExecuteOptions {
|
|
dedupe?: 'cancel' | 'defer'
|
|
}
|
|
|
|
type AsyncDataRequestStatus = 'idle' | 'pending' | 'success' | 'error'
|
|
```
|