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.
Note: There are additional examples in the AbortSignal
reference.
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}`);
});
}
Note: When abort()
is called, the fetch()
promise rejects with a DOMException
named AbortError
.
You can find a full working example on GitHub; you can also see it running live.