AbortController

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.

let controller;
const url = 'video.mp4';

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

downloadBtn.addEventListener('click', fetchVideo);

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

function fetchVideo() {
  controller = new AbortController();
  const signal = controller.signal;
  fetch(url, { signal })
    .then((response) => {
      console.log('Download complete', response);
    })
    .catch((err) => {
      console.error(`Download error: ${err.message}`);
    });
}

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

• Fetch API
• Abortable Fetch by Jake Archibald