**This fork supports IE8 with es5-shim, es5-sham and es6-promise.**
npm install fetch-ie8This fork supports IE8 with es5-shim, es5-sham and es6-promise.
If you also use JSONP, checkout fetch-jsonp.
**Fetch API is still very new and not fully supported in some browsers, so you may
need to check browser verson as well as if window.fetch exists. In this case,
you can set window.__disableNativeFetch = true to use AJAX polyfill always.**
The global fetch function is an easier way to make web requests and handle
responses than using an XMLHttpRequest. This polyfill is written as closely as
possible to the standard Fetch specification at https://fetch.spec.whatwg.org.
``sh`
$ npm install fetch-ie8 --save
You'll also need a Promise polyfill for older browsers.
`sh`
$ npm install es6-promise
Run this to polyfill the global environment at the beginning of your application.
`js`
require('es6-promise').polyfill();
(For a node.js implementation, try node-fetch)
The fetch function supports any HTTP method. We'll focus on GET and POST
example requests.
`javascript`
fetch('/users.html')
.then(function(response) {
return response.text()
}).then(function(body) {
document.body.innerHTML = body
})
`javascript`
fetch('/users.json')
.then(function(response) {
return response.json()
}).then(function(json) {
console.log('parsed json', json)
}).catch(function(ex) {
console.log('parsing failed', ex)
})
`javascript`
fetch('/users.json').then(function(response) {
console.log(response.headers.get('Content-Type'))
console.log(response.headers.get('Date'))
console.log(response.status)
console.log(response.statusText)
})
`javascript
var form = document.querySelector('form')
fetch('/query', {
method: 'post',
body: new FormData(form)
})
`
`javascript`
fetch('/users', {
method: 'post',
headers: {
'Accept': 'application/json',
'Content-Type': 'application/json'
},
body: JSON.stringify({
name: 'Hubot',
login: 'hubot',
})
})
`javascript
var input = document.querySelector('input[type="file"]')
var form = new FormData()
form.append('file', input.files[0])
form.append('user', 'hubot')
fetch('/avatars', {
method: 'post',
body: form
})
`
This causes fetch to behave like jQuery's $.ajax by rejecting the Promise
on HTTP failure status codes like 404, 500, etc. The response is
resolved only on successful, 200 level, status codes.
`javascript
function status(response) {
if (response.status >= 200 && response.status < 300) {
return response
}
throw new Error(response.statusText)
}
function json(response) {
return response.json()
}
fetch('/users')
.then(status)
.then(json)
.then(function(json) {
console.log('request succeeded with json response', json)
}).catch(function(error) {
console.log('request failed', error)
})
`
The Response object has a URL attribute for the final responded resource.Request
Usually this is the same as the url, but in the case of a redirect,responseURL
its all transparent. Newer versions of XHR include a attribute
that returns this value. But not every browser supports this. The compromise
requires setting a special server side header to tell the browser what URL it
just requested (yeah, I know browsers).
` ruby`
response.headers['X-Request-URL'] = request.url
If you want response.url` to be reliable, you'll want to set this header. The
day that you ditch this polyfill and use native fetch only, you can remove the
header hack.
!Chrome | !Firefox | !IE | !Opera | !Safari
--- | --- | --- | --- | --- |
Latest ✔ | Latest ✔ | 8+ ✔ | Latest ✔ | 6.1+ ✔ |