useFetch

If the last argument of useFetch is not a dependency array [], then it will not fire until you call one of the http methods like get, post, etc.

import useFetch from 'use-http'

function Todos() {
  const [todos, setTodos] = useState([])
  const { get, post, response, loading, error } = useFetch('https://example.com')

  useEffect(() => { initializeTodos() }, []) // componentDidMount
  
  async function initializeTodos() {
    const initialTodos = await get('/todos')
    if (response.ok) setTodos(initialTodos)
  }

  async function addTodo() {
    const newTodo = await post('/todos', { title: 'my new todo' })
    if (response.ok) setTodos([...todos, newTodo])
  }

  return (
    <>
      <button onClick={addTodo}>Add Todo</button>
      {error && 'Error!'}
      {loading && 'Loading...'}
      {todos.map(todo => (
        <div key={todo.id}>{todo.title}</div>
      ))}
    </>
  )
}

This fetch is run onMount/componentDidMount. The last argument [] means it will run onMount. If you pass it a variable like [someVariable], it will run onMount and again whenever someVariable changes values (aka onUpdate). If no method is specified, GET is the default.

import useFetch from 'use-http'

function Todos() {
  const options = {} // these options accept all native `fetch` options
  // the last argument below [] means it will fire onMount (GET by default)
  const { loading, error, data = [] } = useFetch('https://example.com/todos', options, [])
  return (
    <>
      {error && 'Error!'}
      {loading && 'Loading...'}
      {data.map(todo => (
        <div key={todo.id}>{todo.title}</div>
      ))}
    </>
  )
}

Can put suspense in 2 places. Either useFetch (A) or Provider (B).

import useFetch, { Provider } from 'use-http'

function Todos() {
  const { data: todos = [] } = useFetch('/todos', {
    suspense: true // A. can put `suspense: true` here
  }, []) // onMount

  return todos.map(todo => <div key={todo.id}>{todo.title}</div>)
}

function App() {
  const options = {
    suspense: true // B. can put `suspense: true` here too
  }
  return (
    <Provider url='https://example.com' options={options}>
      <Suspense fallback='Loading...'>
        <Todos />
      </Suspense>
    </Provider>
  )
}

Can put suspense in 2 places. Either useFetch (A) or Provider (B). Suspense mode via managed state is very experimental.

import useFetch, { Provider } from 'use-http'

function Todos() {
  const [todos, setTodos] = useState([])
  // A. can put `suspense: true` here
  const { get, response } = useFetch({ suspense: true })

  const loadInitialTodos = async () => {
    const todos = await get('/todos')
    if (response.ok) setTodos(todos)
  }

  // componentDidMount
  useEffect(() => {
    loadInitialTodos()
  }, [])

  return todos.map(todo => <div key={todo.id}>{todo.title}</div>)
}

function App() {
  const options = {
    suspense: true // B. can put `suspense: true` here too
  }
  return (
    <Provider url='https://example.com' options={options}>
      <Suspense fallback='Loading...'>
        <Todos />
      </Suspense>
    </Provider>
  )
}

The onNewData will take the current data, and the newly fetched data, and allow you to merge the two however you choose. In the example below, we are appending the new todos to the end of the current todos.

import useFetch, { Provider } from 'use-http'

const Todos = () => {
  const [page, setPage] = useState(1)

  const { data = [], loading } = useFetch(`/todos?page=${page}&amountPerPage=15`, {
    onNewData: (currTodos, newTodos) => [...currTodos, ...newTodos], // appends newly fetched todos
    perPage: 15, // stops making more requests if last todos fetched < 15
  }, [page]) // runs onMount AND whenever the `page` updates (onUpdate)

  return (
    <ul>
      {data.map(todo => <li key={todo.id}>{todo.title}</li>}
      {loading && 'Loading...'}
      {!loading && (
        <button onClick={() => setPage(page + 1)}>Load More Todos</button>
      )}
    </ul>
  )
}

const App = () => (
  <Provider url='https://example.com'>
    <Todos />
  </Provider>
)

⚠️ Do not destructure the response object! Details in this video. Technically you can do it, but if you need to access the response.ok from, for example, within a component's onClick handler, it will be a stale value for ok where it will be correct for response.ok. ️️⚠️

var [request, response, loading, error] = useFetch('https://example.com')

// want to use object destructuring? You can do that too
var {
  request,
  response, // 🚨 Do not destructure the `response` object!
  loading,
  error,
  data,
  cache,    // methods: get, set, has, delete, clear (like `new Map()`)
  get,
  post,
  put,
  patch,
  delete    // don't destructure `delete` though, it's a keyword
  del,      // <- that's why we have this (del). or use `request.delete`
  head,
  options,
  connect,
  trace,
  mutate,   // GraphQL
  query,    // GraphQL
  abort
} = useFetch('https://example.com')

// 🚨 Do not destructure the `response` object!
// 🚨 This just shows what fields are available in it.
var {
  ok,
  status,
  headers,
  data,
  type,
  statusText,
  url,
  body,
  bodyUsed,
  redirected,
  // methods
  json,
  text,
  formData,
  blob,
  arrayBuffer,
  clone
} = response

var {
  loading,
  error,
  data,
  cache,  // methods: get, set, has, delete, clear (like `new Map()`)
  get,
  post,
  put,
  patch,
  delete  // don't destructure `delete` though, it's a keyword
  del,    // <- that's why we have this (del). or use `request.delete`
  mutate, // GraphQL
  query,  // GraphQL
  abort
} = request

var request = useFetch('https://example.com')

request.post('/todos', {
  no: 'way'
})

const { get, abort, loading, data: repos } = useFetch('https://api.github.com/search/repositories?q=')

// the line below is not isomorphic, but for simplicity we're using the browsers `encodeURI`
const searchGithubRepos = e => get(encodeURI(e.target.value))

<>
  <input onChange={searchGithubRepos} />
  <button onClick={abort}>Abort</button>
  {loading ? 'Loading...' : repos.data.items.map(repo => (
    <div key={repo.id}>{repo.name}</div>
  ))}
</>

const QUERY = `
  query Todos($userID string!) {
    todos(userID: $userID) {
      id
      title
    }
  }
`

function App() {
  const request = useFetch('http://example.com')

  const getTodosForUser = id => request.query(QUERY, { userID: id })

  return (
    <>
      <button onClick={() => getTodosForUser('theUsersID')}>Get User's Todos</button>
      {request.loading ? 'Loading...' : <pre>{request.data}</pre>}
    </>
  )
}

The Provider allows us to set a default url, options (such as headers) and so on.

const MUTATION = `
  mutation CreateTodo($todoTitle string) {
    todo(title: $todoTitle) {
      id
      title
    }
  }
`

function App() {
  const [todoTitle, setTodoTitle] = useState('')
  const request = useFetch('http://example.com')

  const createtodo = () => request.mutate(MUTATION, { todoTitle })

  return (
    <>
      <input onChange={e => setTodoTitle(e.target.value)} />
      <button onClick={createTodo}>Create Todo</button>
      {request.loading ? 'Loading...' : <pre>{request.data}</pre>}
    </>
  )
}

Query for todos

import { useQuery } from 'use-http'

export default function QueryComponent() {
  
  // can also do it this way:
  // const [data, loading, error, query] = useQuery`
  // or this way:
  // const { data, loading, error, query } = useQuery`
  const request = useQuery`
    query Todos($userID string!) {
      todos(userID: $userID) {
        id
        title
      }
    }
  `

  const getTodosForUser = id => request.query({ userID: id })
  
  return (
    <>
      <button onClick={() => getTodosForUser('theUsersID')}>Get User's Todos</button>
      {request.loading ? 'Loading...' : <pre>{request.data}</pre>}
    </>
  )
}

Add a new todo

import { useMutation } from 'use-http'

export default function MutationComponent() {
  const [todoTitle, setTodoTitle] = useState('')
  
  // can also do it this way:
  // const request = useMutation`
  // or this way:
  // const { data, loading, error, mutate } = useMutation`
  const [data, loading, error, mutate] = useMutation`
    mutation CreateTodo($todoTitle string) {
      todo(title: $todoTitle) {
        id
        title
      }
    }
  `
  
  const createTodo = () => mutate({ todoTitle })

  return (
    <>
      <input onChange={e => setTodoTitle(e.target.value)} />
      <button onClick={createTodo}>Create Todo</button>
      {loading ? 'Loading...' : <pre>{data}</pre>}
    </>
  )
}

Adding the Provider

These props are defaults used in every request inside the <Provider />. They can be overwritten individually

import { Provider } from 'use-http'
import QueryComponent from './QueryComponent'
import MutationComponent from './MutationComponent'

function App() {

  const options = {
    headers: {
      Authorization: 'Bearer YOUR_TOKEN_HERE'
    }
  }
  
  return (
    <Provider url='http://example.com' options={options}>
      <QueryComponent />
      <MutationComponent />
    <Provider/>
  )
}

This example shows how we can do authentication in the request interceptor and how we can camelCase the results in the response interceptor

import { Provider } from 'use-http'
import { toCamel } from 'convert-keys'

function App() {
  let [token, setToken] = useLocalStorage('token')
  
  const options = {
    interceptors: {
      // every time we make an http request, this will run 1st before the request is made
      // url, path and route are supplied to the interceptor
      // request options can be modified and must be returned
      request: async ({ options, url, path, route }) => {
        if (isExpired(token)) {
          token = await getNewToken()
          setToken(token)
        }
        options.headers.Authorization = `Bearer ${token}`
        return options
      },
      // every time we make an http request, before getting the response back, this will run
      response: async ({ response, request }) => {
        // unfortunately, because this is a JS Response object, we have to modify it directly.
        // It shouldn't have any negative affect since this is getting reset on each request.
        const res = response
        if (res.data) res.data = toCamel(res.data)
        return res
      }
    }
  }
  
  return (
    <Provider url='http://example.com' options={options}>
      <SomeComponent />
    <Provider/>
  )
}

This example shows how we can upload a file using useFetch.

import useFetch from 'use-http'

const FileUploader = () => {
  const [file, setFile] = useState()
  
  const { post } = useFetch('https://example.com/upload')

  const uploadFile = async () => {
    const data = new FormData()
    data.append('file', file)
    if (file instanceof FormData) await post(data)
  }

  return (
    <div>
      {/* Drop a file onto the input below */}
      <input onChange={e => setFile(e.target.files[0])} />
      <button onClick={uploadFile}>Upload</button>
    </div>
  )
}

This example shows how we can get .json(), .text(), .formData(), .blob(), .arrayBuffer(), and all the other http response methods. By default, useFetch 1st tries to call response.json() under the hood, if that fails it's backup is response.text(). If that fails, then you need a different response type which is where this comes in.

import useFetch from 'use-http'

const App = () => {
  const [name, setName] = useState('')
  
  const { get, loading, error, response } = useFetch('http://example.com')

  const handleClick = async () => {
    await get('/users/1?name=true') // will return just the user's name
    const text = await response.text()
    setName(text)
  }
  
  return (
    <>
      <button onClick={handleClick}>Load Data</button>
      {error && error.messge}
      {loading && "Loading..."}
      {name && <div>{name}</div>}
    </>
  )
}

This example shows how to remove a header all together. Let's say you have <Provider url='url.com' options={{ headers: { Authentication: 'Bearer MY_TOKEN' } }}><App /></Provider>, but for one api call, you don't want that header in your useFetch at all for one instance in your app. This would allow you to remove that.

import useFetch from 'use-http'

const Todos = () => {
  // let's say for this request, you don't want the `Accept` header at all
  const { loading, error, data: todos = [] } = useFetch('/todos', globalOptions => {
    delete globalOptions.headers.Accept
    return globalOptions
  }, []) // onMount
  return (
    <>
      {error && error.messge}
      {loading && "Loading..."}
      {todos && <ul>{todos.map(todo => <li key={todo.id}>{todo.title}</li>)}</ul>}
    </>
  )
}

const App = () => {
  const options = {
    headers: {
      Accept: 'application/json'
    }
  }
  return (
    <Provider url='https://url.com' options={options}><Todos /></Provider>
}

In this example you can see how retryOn will retry on a status code of 305, or if we choose the retryOn() function, it returns a boolean to decide if we will retry. With retryDelay we can either have a fixed delay, or a dynamic one by using retryDelay(). Make sure retries is set to at minimum 1 otherwise it won't retry the request. If retries > 0 without retryOn then by default we always retry if there's an error or if !response.ok. If retryOn: [400] and retries > 0 then we only retry on a response status of 400.

import useFetch from 'use-http'

const TestRetry = () => {
  const { response, get } = useFetch('https://httpbin.org/status/305', {
    // make sure `retries` is set otherwise it won't retry
    retries: 1,
    retryOn: [305],
    // OR
    retryOn: async ({ attempt, error, response }) => {
      // returns true or false to determine whether to retry
      return error || response && response.status >= 300
    },

    retryDelay: 3000,
    // OR
    retryDelay: ({ attempt, error, response }) => {
      // exponential backoff
      return Math.min(attempt > 1 ? 2 ** attempt * 1000 : 1000, 30 * 1000)
      // linear backoff
      return attempt * 1000
    }
  })

  return (
    <>
      <button onClick={() => get()}>CLICK</button>
      <pre>{JSON.stringify(response, null, 2)}</pre>
    </>
  )
}