useFetch

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响应式 Fetch API 提供了中止请求、在请求发出前拦截请求、在 URL 更改时自动重新获取请求以及使用预定义选项创建您自己的 useFetch 的能力。

通过 Vue School 的此免费视频课程学习 useFetch！

提示

在与 Nuxt 3 一起使用时，此函数将**不会**自动导入，以支持 Nuxt 自带的 useFetch()。如果要使用来自 VueUse 的函数，请使用显式导入。

演示

来源

以下 URL 可用于测试 useFetch 的不同功能

普通请求： https://httpbin.org/get

中止请求： https://httpbin.org/delay/10

响应错误： http://httpbin.org/status/500

isFinished: false
isFetching: false
canAbort: false
statusCode: null
error: null
data: null

用法

基本用法

useFetch 函数只需提供一个 url 即可使用。url 可以是字符串或ref。data 对象将包含请求的结果，error 对象将包含任何错误，isFetching 对象将指示请求是否正在加载。

import { useFetch } from '@vueuse/core'

const { isFetching, error, data } = useFetch(url)

异步用法

useFetch 也可以像普通 fetch 一样等待。请注意，每当组件是异步时，使用它的任何组件都必须将组件包装在<Suspense>标签中。您可以在官方 Vue 3 文档中阅读更多关于 suspense api 的信息。

import { useFetch } from '@vueuse/core'

const { isFetching, error, data } = await useFetch(url)

在 URL 更改时重新获取

对 url 参数使用ref将允许useFetch函数在 url 更改时自动触发另一个请求。

const url = ref('https://my-api.com/user/1')

const { data } = useFetch(url, { refetch: true })

url.value = 'https://my-api.com/user/2' // Will trigger another request

防止请求立即发出

将immediate选项设置为 false 将阻止请求发出，直到调用execute函数。

const { execute } = useFetch(url, { immediate: false })

execute()

中止请求

可以使用useFetch函数中的abort函数中止请求。canAbort属性指示请求是否可以中止。

const { abort, canAbort } = useFetch(url)

setTimeout(() => {
  if (canAbort.value)
    abort()
}, 100)

也可以通过使用timeout属性自动中止请求。当达到给定的超时时间时，它将调用abort函数。

const { data } = useFetch(url, { timeout: 100 })

拦截请求

beforeFetch选项可以在发送请求之前拦截请求，并修改请求选项和URL。

const { data } = useFetch(url, {
  async beforeFetch({ url, options, cancel }) {
    const myToken = await getMyToken()

    if (!myToken)
      cancel()

    options.headers = {
      ...options.headers,
      Authorization: `Bearer ${myToken}`,
    }

    return {
      options,
    }
  },
})

afterFetch选项可以在更新响应数据之前拦截响应数据。

const { data } = useFetch(url, {
  afterFetch(ctx) {
    if (ctx.data.title === 'HxH')
      ctx.data.title = 'Hunter x Hunter' // Modifies the response data

    return ctx
  },
})

当updateDataOnError设置为true时，onFetchError选项可以在更新响应数据和错误之前拦截响应数据和错误。

const { data } = useFetch(url, {
  updateDataOnError: true,
  onFetchError(ctx) {
    // ctx.data can be null when 5xx response
    if (ctx.data === null)
      ctx.data = { title: 'Hunter x Hunter' } // Modifies the response data

    ctx.error = new Error('Custom Error') // Modifies the error
    return ctx
  },
})

console.log(data.value) // { title: 'Hunter x Hunter' }

设置请求方法和返回类型

可以通过在useFetch的末尾添加相应的方法来设置请求方法和返回类型。

// Request will be sent with GET method and data will be parsed as JSON
const { data } = useFetch(url).get().json()

// Request will be sent with POST method and data will be parsed as text
const { data } = useFetch(url).post().text()

// Or set the method using the options

// Request will be sent with GET method and data will be parsed as blob
const { data } = useFetch(url, { method: 'GET' }, { refetch: true }).blob()

创建自定义实例

createFetch函数将返回一个useFetch函数，该函数具有提供给它的任何预配置选项。这对于与在整个应用程序中使用相同基本URL或需要授权标头的API交互非常有用。

const useMyFetch = createFetch({
  baseUrl: 'https://my-api.com',
  options: {
    async beforeFetch({ options }) {
      const myToken = await getMyToken()
      options.headers.Authorization = `Bearer ${myToken}`

      return { options }
    },
  },
  fetchOptions: {
    mode: 'cors',
  },
})

const { isFetching, error, data } = useMyFetch('users')

如果要控制预配置实例和新生成的实例之间beforeFetch、afterFetch、onFetchError的行为。您可以提供一个combination选项在overwrite或chaining之间切换。

const useMyFetch = createFetch({
  baseUrl: 'https://my-api.com',
  combination: 'overwrite',
  options: {
    // beforeFetch in pre-configured instance will only run when the newly spawned instance do not pass beforeFetch
    async beforeFetch({ options }) {
      const myToken = await getMyToken()
      options.headers.Authorization = `Bearer ${myToken}`

      return { options }
    },
  },
})

// use useMyFetch beforeFetch
const { isFetching, error, data } = useMyFetch('users')

// use custom beforeFetch
const { isFetching, error, data } = useMyFetch('users', {
  async beforeFetch({ url, options, cancel }) {
    const myToken = await getMyToken()

    if (!myToken)
      cancel()

    options.headers = {
      ...options.headers,
      Authorization: `Bearer ${myToken}`,
    }

    return {
      options,
    }
  },
})

事件

onFetchResponse和onFetchError分别会在获取请求响应和错误时触发。

const { onFetchResponse, onFetchError } = useFetch(url)

onFetchResponse((response) => {
  console.log(response.status)
})

onFetchError((error) => {
  console.error(error.message)
})

类型声明

显示类型声明

typescript

export interface UseFetchReturn<T> {
  /**
   * Indicates if the fetch request has finished
   */
  isFinished: Readonly<Ref<boolean>>
  /**
   * The statusCode of the HTTP fetch response
   */
  statusCode: Ref<number | null>
  /**
   * The raw response of the fetch response
   */
  response: Ref<Response | null>
  /**
   * Any fetch errors that may have occurred
   */
  error: Ref<any>
  /**
   * The fetch response body on success, may either be JSON or text
   */
  data: Ref<T | null>
  /**
   * Indicates if the request is currently being fetched.
   */
  isFetching: Readonly<Ref<boolean>>
  /**
   * Indicates if the fetch request is able to be aborted
   */
  canAbort: ComputedRef<boolean>
  /**
   * Indicates if the fetch request was aborted
   */
  aborted: Ref<boolean>
  /**
   * Abort the fetch request
   */
  abort: Fn
  /**
   * Manually call the fetch
   * (default not throwing error)
   */
  execute: (throwOnFailed?: boolean) => Promise<any>
  /**
   * Fires after the fetch request has finished
   */
  onFetchResponse: EventHookOn<Response>
  /**
   * Fires after a fetch request error
   */
  onFetchError: EventHookOn
  /**
   * Fires after a fetch has completed
   */
  onFetchFinally: EventHookOn
  get: () => UseFetchReturn<T> & PromiseLike<UseFetchReturn<T>>
  post: (
    payload?: MaybeRefOrGetter<unknown>,
    type?: string,
  ) => UseFetchReturn<T> & PromiseLike<UseFetchReturn<T>>
  put: (
    payload?: MaybeRefOrGetter<unknown>,
    type?: string,
  ) => UseFetchReturn<T> & PromiseLike<UseFetchReturn<T>>
  delete: (
    payload?: MaybeRefOrGetter<unknown>,
    type?: string,
  ) => UseFetchReturn<T> & PromiseLike<UseFetchReturn<T>>
  patch: (
    payload?: MaybeRefOrGetter<unknown>,
    type?: string,
  ) => UseFetchReturn<T> & PromiseLike<UseFetchReturn<T>>
  head: (
    payload?: MaybeRefOrGetter<unknown>,
    type?: string,
  ) => UseFetchReturn<T> & PromiseLike<UseFetchReturn<T>>
  options: (
    payload?: MaybeRefOrGetter<unknown>,
    type?: string,
  ) => UseFetchReturn<T> & PromiseLike<UseFetchReturn<T>>
  json: <JSON = any>() => UseFetchReturn<JSON> &
    PromiseLike<UseFetchReturn<JSON>>
  text: () => UseFetchReturn<string> & PromiseLike<UseFetchReturn<string>>
  blob: () => UseFetchReturn<Blob> & PromiseLike<UseFetchReturn<Blob>>
  arrayBuffer: () => UseFetchReturn<ArrayBuffer> &
    PromiseLike<UseFetchReturn<ArrayBuffer>>
  formData: () => UseFetchReturn<FormData> &
    PromiseLike<UseFetchReturn<FormData>>
}
type Combination = "overwrite" | "chain"
export interface BeforeFetchContext {
  /**
   * The computed url of the current request
   */
  url: string
  /**
   * The request options of the current request
   */
  options: RequestInit
  /**
   * Cancels the current request
   */
  cancel: Fn
}
export interface AfterFetchContext<T = any> {
  response: Response
  data: T | null
}
export interface OnFetchErrorContext<T = any, E = any> {
  error: E
  data: T | null
}
export interface UseFetchOptions {
  /**
   * Fetch function
   */
  fetch?: typeof window.fetch
  /**
   * Will automatically run fetch when `useFetch` is used
   *
   * @default true
   */
  immediate?: boolean
  /**
   * Will automatically refetch when:
   * - the URL is changed if the URL is a ref
   * - the payload is changed if the payload is a ref
   *
   * @default false
   */
  refetch?: MaybeRefOrGetter<boolean>
  /**
   * Initial data before the request finished
   *
   * @default null
   */
  initialData?: any
  /**
   * Timeout for abort request after number of millisecond
   * `0` means use browser default
   *
   * @default 0
   */
  timeout?: number
  /**
   * Allow update the `data` ref when fetch error whenever provided, or mutated in the `onFetchError` callback
   *
   * @default false
   */
  updateDataOnError?: boolean
  /**
   * Will run immediately before the fetch request is dispatched
   */
  beforeFetch?: (
    ctx: BeforeFetchContext,
  ) =>
    | Promise<Partial<BeforeFetchContext> | void>
    | Partial<BeforeFetchContext>
    | void
  /**
   * Will run immediately after the fetch request is returned.
   * Runs after any 2xx response
   */
  afterFetch?: (
    ctx: AfterFetchContext,
  ) => Promise<Partial<AfterFetchContext>> | Partial<AfterFetchContext>
  /**
   * Will run immediately after the fetch request is returned.
   * Runs after any 4xx and 5xx response
   */
  onFetchError?: (ctx: {
    data: any
    response: Response | null
    error: any
  }) => Promise<Partial<OnFetchErrorContext>> | Partial<OnFetchErrorContext>
}
export interface CreateFetchOptions {
  /**
   * The base URL that will be prefixed to all urls unless urls are absolute
   */
  baseUrl?: MaybeRefOrGetter<string>
  /**
   * Determine the inherit behavior for beforeFetch, afterFetch, onFetchError
   * @default 'chain'
   */
  combination?: Combination
  /**
   * Default Options for the useFetch function
   */
  options?: UseFetchOptions
  /**
   * Options for the fetch request
   */
  fetchOptions?: RequestInit
}
export declare function createFetch(
  config?: CreateFetchOptions,
): typeof useFetch
export declare function useFetch<T>(
  url: MaybeRefOrGetter<string>,
): UseFetchReturn<T> & PromiseLike<UseFetchReturn<T>>
export declare function useFetch<T>(
  url: MaybeRefOrGetter<string>,
  useFetchOptions: UseFetchOptions,
): UseFetchReturn<T> & PromiseLike<UseFetchReturn<T>>
export declare function useFetch<T>(
  url: MaybeRefOrGetter<string>,
  options: RequestInit,
  useFetchOptions?: UseFetchOptions,
): UseFetchReturn<T> & PromiseLike<UseFetchReturn<T>>