The Request
interface of the Fetch API represents a resource request.
You can create a new Request
object using the Request.Request()
constructor, but you are more likely to encounter a Request
object being returned as the result of another API operation, such as a service worker FetchEvent.request
.
Constructor
Request.Request()
- Creates a new
Request
object.
Properties
Request.method
Read only- Contains the request's method (
GET
,POST
, etc.) Request.url
Read only- Contains the URL of the request.
Request.headers
Read only- Contains the associated
Headers
object of the request. Request.context
Read only- Contains the context of the request (e.g.,
audio
,image
,iframe
, etc.) Request.referrer
Read only- Contains the referrer of the request (e.g.,
client
). Request.referrerPolicy
Read only- Contains the referrer policy of the request (e.g.,
no-referrer
). Request.mode
Read only- Contains the mode of the request (e.g.,
cors
,no-cors
,same-origin
,navigate
.) Request.credentials
Read only- Contains the credentials of the request (e.g.,
omit
,same-origin
). Request.redirect
Read only- Contains the mode for how redirects are handled. It may be one of
follow
,error
, ormanual
. Request.integrity
Read only- Contains the subresource integrity value of the request (e.g.,
sha256-BpfBw7ivV8q2jLiT13fxDYAe2tJllusRSZ273h2nFSE=
). Request.cache
Read only- Contains the cache mode of the request (e.g.,
default
,reload
,no-cache
).
Request
implements Body
, so it also has the following property available to it:
Body.bodyUsed
Read only- Stores a
Boolean
that declares whether the body has been used in a response yet.
Methods
Request.clone()
- Creates a copy of the current
Request
object.
Request
implements Body
, so it also has the following methods available to it:
Body.arrayBuffer()
- Returns a promise that resolves with an
ArrayBuffer
representation of the request body. Body.blob()
- Returns a promise that resolves with a
Blob
representation of the request body. Body.formData()
- Returns a promise that resolves with a
FormData
representation of the request body. Body.json()
- Returns a promise that resolves with a
JSON
representation of the request body. Body.text()
- Returns a promise that resolves with an
USVString
(text) representation of the request body.
Note: The Body
functions can be run only once; subsequent calls will resolve with empty strings/ArrayBuffers.
Examples
In the following snippet, we create a new request using the Request()
constructor (for an image file in the same directory as the script), then return some property values of the request:
var myRequest = new Request('http://localhost/flowers.jpg'); var myURL = myRequest.url; // http://localhost/flowers.jpg var myMethod = myRequest.method; // GET var myCred = myRequest.credentials; // omit
You could then fetch this request by passing the Request
object in as a parameter to a GlobalFetch.fetch()
call, for example:
fetch(myRequest) .then(function(response) { return response.blob(); }) .then(function(response) { var objectURL = URL.createObjectURL(response); myImage.src = objectURL; });
In the following snippet, we create a new request using the Request()
constructor with some initial data and body content for an api request which need a body payload:
var myRequest = new Request('http://localhost/api', {method: 'POST', body: '{"foo":"bar"}'}); var myURL = myRequest.url; // http://localhost/api var myMethod = myRequest.method; // POST var myCred = myRequest.credentials; // omit var bodyUsed = myRequest.bodyUsed; // true
Note: The body type can only be a Blob
, BufferSource
, FormData
, URLSearchParams
, USVString
or ReadableStream
type, so for adding a JSON object to the payload you need to stringify that object.
You could then fetch this api request by passing the Request
object in as a parameter to a GlobalFetch.fetch()
call, for example and get the response:
fetch(myRequest) .then(function(response) { if(response.status == 200) return response.json(); else throw new Error('Something went wrong on api server!'); }) .then(function(response) { console.debug(response); // ... }) .catch(function(error) { console.error(error); });
Specifications
Specification | Status | Comment |
---|---|---|
Fetch The definition of 'Request' in that specification. |
Living Standard | Initial definition |
Browser compatibility
Feature | Chrome | Edge | Firefox (Gecko) | Internet Explorer | Opera | Safari (WebKit) |
---|---|---|---|---|---|---|
Basic support |
42 |
(Yes) | 39 (39) 34[1] |
No support |
29 |
No support |
Request.integrity |
46 | ? | (Yes) | No support | 33 | No support |
Request.redirect |
46 | ? | (Yes) | ? | 33 | ? |
Feature | Android Webview | Chrome for Android | Edge | Firefox Mobile (Gecko) | IE Phone | Opera Mobile | Safari Mobile |
---|---|---|---|---|---|---|---|
Basic support | No support | 42 | (Yes) | (Yes) | No support | (Yes) | No support |
Request.integrity |
No support | 46 | ? | (Yes) | No support | 33 | No support |
Request.redirect |
No support | 46 | ? | (Yes) | No support | 33 | No support |