Abort a fetch

Since fetch is introduced in browser has passed nearly one decade. But in the beginning, it does no have a method to cancel request. AbortController is the solution to abort a request send by fetch.

AbortController use an AbortSignal to cancel fetch request.

The demo code:

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

const url = "video.mp4";
const downloadBtn = document.querySelector(".download");
const abortBtn = document.querySelector(".abort");

downloadBtn.addEventListener("click", fetchVideo);

abortBtn.addEventListener("click", () => {
  const reason = 'User cancel download by click the cancel button';
  controller.abort(reason);
  console.log("Download aborted");
});

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

• Note:

When abort() is called, the fetch() promise rejects with an Error of type DOMException, with name AbortError.