AbortController.signal
The signal
read-only property of the AbortController
interface returns an AbortSignal
object instance, which can be used to communicate with/abort a DOM request as desired.
Value
An AbortSignal
object instance.
Examples
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;
})
}
Note: When abort()
is called, the fetch()
promise rejects with an AbortError
.
You can find a full working example on GitHub; you can also see it running live.
Specifications
Specification |
---|
DOM Standard # ref-for-dom-abortcontroller-signal② |
Browser compatibility
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