Body.bodyUsed

This is an experimental technology
Because this technology's specification has not stabilized, check the compatibility table for the proper prefixes to use in various browsers. Also note that the syntax and behavior of an experimental technology is subject to change in future versions of browsers as the spec changes.

The bodyUsed read-only property of the Body mixin contains a Boolean that indicates whether the body has been read yet.

Syntax

JavaScript
var myBodyUsed = response.bodyUsed;

Value

A Boolean.

Example

In our fetch request example (run fetch request live), we create a new request using the Request.Request constructor, then use it to fetch a JPG. When the fetch is successful, we read a Blob out of the response using blob(), put it into an object URL using URL.createObjectURL, and then set that URL as the source of an <img> element to display the image.

Notice that we log response.bodyUsed to the console once before the response.blob() call and once after. This returns false before and true afterwards, as at that point the body has been read.

JavaScript
var myImage = document.querySelector('img');

var myRequest = new Request('flowers.jpg');

fetch(myRequest).then(function(response) {
  console.log(response.bodyUsed);
  response.blob().then(function(myBlob) {
    var objectURL = URL.createObjectURL(myBlob);
    myImage.src = objectURL;
  });
  console.log(response.bodyUsed);
});

Specifications

Specification Status Comment
Fetch
The definition of 'bodyUsed' in that specification.
Living Standard  

Browser compatibility

Feature Chrome Firefox (Gecko) Internet Explorer Opera Safari (WebKit)
Basic support 42 [1]
 
39 (39) [2] Not supported

29 [3]

Not supported
Feature Android Firefox Mobile (Gecko) Firefox OS (Gecko) IE Phone Opera Mobile Safari Mobile Chrome for Android
Basic support Not supported Not supported Not supported Not supported Not supported Not supported Not supported

[1] Behind a preference in version 41.

[2] Behind a preference starting with version 34.

[3] Behind a preference in version 28.

See also

License

© 2016 Mozilla Contributors
Licensed under the Creative Commons Attribution-ShareAlike License v2.5 or later.
https://developer.mozilla.org/en-us/docs/web/api/body/bodyused

API BODY bodyUsed Experimental Fetch Property Reference