TaskSignal: any() static method

Limited availability

This feature is not Baseline because it does not work in some of the most widely-used browsers.

Experimental: This is an experimental technology
Check the Browser compatibility table carefully before using this in production.

Note: This feature is available in Web Workers.

The TaskSignal.any() static method takes an iterable of AbortSignal objects and returns a TaskSignal. The returned task signal is aborted when any of the abort signals is aborted.

When the task signal is aborted, its reason property will be set to the reason of the first signal that is aborted.

Syntax

js
TaskSignal.any(signals)
TaskSignal.any(signals, init)

Parameters

signals

An iterable (such as an Array) of abort signals.

init Optional

Contains optional configuration parameters. Currently only one property is defined:

priority Optional

One of the following:

  • A string which is one of user-blocking, user-visible and background.
  • A TaskSignal.

Return value

A TaskSignal instance. It will be aborted when the first signal passed into signals is aborted. When this happens:

  • Its reason property will be set to the reason of the signal that caused this signal to abort.

  • Its priority property will be determined by the priority parameter:

    • If the priority parameter was a string, it will be the value of the string.
    • If the priority parameter was a TaskSignal, it will be the value of that signal's priority.

Examples

Using TaskSignal.any()

This example demonstrates combining both a signal from a TaskController, and a timeout signal from TaskSignal.timeout().

js
const cancelDownloadButton = document.getElementById("cancelDownloadButton");

const userCancelController = new TaskController({
  priority: "user-visible",
});

cancelDownloadButton.addEventListener("click", () => {
  userCancelController.abort();
});

// Timeout after 5 minutes
const timeoutSignal = TaskSignal.timeout(1_000 * 60 * 5);

// This signal will abort when either the user clicks the cancel button or 5 minutes is up whichever is sooner
const combinedSignal = TaskSignal.any([
  userCancelController.signal,
  timeoutSignal,
]);

try {
  const res = await fetch(someUrlToDownload, {
    // Stop the fetch when any of the
    signal: combinedSignal,
  });
  const body = await res.blob();
  // Do something with downloaded content
  // ...
} catch (e) {
  if (e.name === "AbortError") {
    // Cancelled by the user
  } else if (e.name === "TimeoutError") {
    // Show user that download timed out
  } else {
    // Other error, e.g. network error
  }
}

Specifications

Specification
Prioritized Task Scheduling
# dom-tasksignal-any

Browser compatibility

BCD tables only load in the browser

See also