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Browser

useFetch

Reactive Fetch API provides the ability to abort requests, intercept requests before they are fired, automatically refetch requests when the url changes, and create your own useFetch with predefined options.

[[toc]]

Usage

Basic Usage

The useFetch funciton can be used by simply providing a url. The url can be either a string or a ref. The data object will contain the result of the request, the error object will contain any errors, and the isFetching object will indicate if the request is loading.

import { useFetch } from '@vueuse/core'

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

Refetching on URL change

Using a ref for the url parameter will allow the useFetch function to automatically trigger another request when the url is changed.

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

Prevent request from firing immediately

Setting the immediate option to false will prevent the request from firing until the execute function is called.

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

execute()

Aborting a request

A request can be aborted by using the abort function from the useFetch function. The canAbort property indicates if the request can be aborted

const { abort, canAbort } = useFetch(url)

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

Intercepting a request

The beforeFetch option can intercept a request before it is sent and modify the request options and url.

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

    if (!myToken)
      cancel()

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

    return {
      options
    }
  }
})

Setting the request method and return type

The requset method and return type can be set by adding the appropite methods to the end of useFetch

// 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()

Creating a custom instance

The createFetch function will return a useFetch function with whatever preconfigured options that are provided to it. This is useful for interacting with API's thoughout an application that uses the same base URL or needs Authorization headers.

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')

Type Declarations

interface UseFetchReturnBase<T> {
  /**
   * Indicates if the fetch request has finished
   */
  isFinished: 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 occured
   */
  error: Ref<any>
  /**
   * The fetch response body, may either be JSON or text
   */
  data: Ref<T | null>
  /**
   * Indicates if the request is currently being fetched.
   */
  isFetching: 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
   */
  execute: () => Promise<any>
}
declare type PayloadType = "text" | "json" | "formData"
interface UseFetchReturnMethodConfigured<T> extends UseFetchReturnBase<T> {
  json<JSON = any>(): UseFetchReturnBase<JSON>
  text(): UseFetchReturnBase<string>
  blob(): UseFetchReturnBase<Blob>
  arrayBuffer(): UseFetchReturnBase<ArrayBuffer>
  formData(): UseFetchReturnBase<FormData>
}
export interface UseFetchReturn<T> extends UseFetchReturnMethodConfigured<T> {
  get(): UseFetchReturnMethodConfigured<T>
  post(payload?: unknown, type?: PayloadType): UseFetchReturnMethodConfigured<T>
  put(payload?: unknown, type?: PayloadType): UseFetchReturnMethodConfigured<T>
  delete(
    payload?: unknown,
    type?: PayloadType
  ): UseFetchReturnMethodConfigured<T>
}
export interface BeforeFetchContext {
  /**
   * The computed url of the current request
   */
  url: string
  /**
   * The requset options of the current request
   */
  options: RequestInit
  /**
   * Cancels the current requset
   */
  cancel: Fn
}
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
   *
   * @default false
   */
  refetch?: MaybeRef<boolean>
  /**
   * Will run immediately before the fetch request is dispatched
   */
  beforeFetch?: (
    ctx: BeforeFetchContext
  ) => Promise<Partial<BeforeFetchContext>> | Partial<BeforeFetchContext>
}
export interface CreateFetchOptions {
  /**
   * The base URL that will be prefixed to all urls
   */
  baseUrl?: MaybeRef<string>
  /**
   * 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: MaybeRef<string>): UseFetchReturn<T>
export declare function useFetch<T>(
  url: MaybeRef<string>,
  useFetchOptions: UseFetchOptions
): UseFetchReturn<T>
export declare function useFetch<T>(
  url: MaybeRef<string>,
  options: RequestInit,
  useFetchOptions?: UseFetchOptions
): UseFetchReturn<T>
export {}

Source

Source • Demo • Docs