This is an experimental technology
Because this technology's specification has not stabilized, check the compatibility table for usage 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 specification changes.
The abort() method of the FetchController interface aborts a fetch request before it has completed.
Syntax
controller.abort();
Parameters
None.
Return value
Void.
Examples
In the following snippet, we create a new FetchController object, get its signal, and then give the signal to the fetch request via the signal parameter of its init object so the controller can control it. Later on we specify an event listener on a cancel button so that when the button is clicked, we abort the fetch request using FetchController.abort().
var controller = new FetchController();
var signal = controller.signal;
downloadBtn.addEventListener('click', function() {
fetch(url, {signal}).then( ... ) // do something with the response
});
cancelBtn.addEventListener('click', function() {
controller.abort();
});
You can find a work-in-progress demo showing usage of FetchController on GitHub (see the source code and the live example).
Specifications
Not part of a specification yet.
Browser compatibility
| Feature | Chrome | Edge | Firefox (Gecko) | Internet Explorer | Opera | Safari (WebKit) |
|---|---|---|---|---|---|---|
| Basic support |
No support |
No support | No support[1] | No support |
No support |
No support |
| Feature | Android | Android Webview | Edge | Firefox Mobile (Gecko) | IE Phone | Opera Mobile | Safari Mobile | Chrome for Android |
|---|---|---|---|---|---|---|---|---|
| Basic support | No support | No support | No support | No support[1] | No support | No support | No support | No support |
[1] Hidden behind a preference in 55+ Nightly. In about:config, you need to create two new boolean prefs — dom.fetchObserver.enabled and dom.fetchController.enabled — and set the values of both to true.