AbortController

The AbortController interface represents a controller object that allows you to abort one or more Web requests as and when desired.

You can create a new AbortController object using the AbortController() constructor. Communicating with a DOM request is done using an AbortSignal object.

AbortController()

Creates a new AbortController object instance.

AbortController.signal Read only

Returns an AbortSignal object instance, which can be used to communicate with, or to abort, a DOM request.

AbortController.abort()

Aborts a DOM request before it has completed. This is able to abort fetch requests, consumption of any response bodies, and streams.

In the following snippet, we aim to download a video using the Fetch API.

We first create a controller using the AbortController() constructor, then grab a reference to its associated AbortSignal object using the AbortController.signal property.

When the fetch request is initiated, we pass in the AbortSignal as an option inside the request's options object (the {signal} below). This associates the signal and controller with the fetch request and allows us to abort it by calling AbortController.abort(), as seen below in the second event listener.

var controller = new AbortController();
var signal = controller.signal;

var downloadBtn = document.querySelector('.download');
var abortBtn = document.querySelector('.abort');

downloadBtn.addEventListener('click', fetchVideo);

abortBtn.addEventListener('click', function() {
  controller.abort();
  console.log('Download aborted');
});

function fetchVideo() {
  ...
  fetch(url, {signal}).then(function(response) {
    ...
  }).catch(function(e) {
   reports.textContent = 'Download error: ' + e.message;
  })
}

You can find a full working example on GitHub; you can also see it running live.

• Fetch API
• Abortable Fetch by Jake Archibald