TaskPriorityChangeEvent

Limited availability

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

Note: This feature is available in Web Workers.

The TaskPriorityChangeEvent is the interface for the prioritychange event.

Event TaskPriorityChangeEvent

Constructor

TaskPriorityChangeEvent()

Creates a new TaskPriorityChangeEvent object, setting an event name and previous priority.

Instance properties

This interface also inherits the properties of its parent, Event.

TaskPriorityChangeEvent.previousPriority Read only

Returns the priority of the corresponding TaskSignal before this prioritychange event.

Instance methods

This interface has no methods of its own, but inherits the methods of its parent, Event.

Examples

An object of this type is returned in the handler for a prioritychange event. The code below shows a handler in which the newPriority and previousPriority are logged.

js
// Listen for 'prioritychange' events on the controller's signal.
controller.signal.addEventListener("prioritychange", (event) => {
  const previousPriority = event.previousPriority;
  const newPriority = event.target.priority;
  console.log(`Priority changed from ${previousPriority} to ${newPriority}.`);
});

A more complete live example can be found in prioritychange event > Examples.

Specifications

Specification
Prioritized Task Scheduling
# sec-task-priority-change-event

Browser compatibility

Report problems with this compatibility data on GitHub
desktopmobile
Chrome
Edge
Firefox
Opera
Safari
Chrome Android
Firefox for Android
Opera Android
Safari on iOS
Samsung Internet
WebView Android
WebView on iOS
TaskPriorityChangeEvent
TaskPriorityChangeEvent() constructor
previousPriority

Legend

Tip: you can click/tap on a cell for more information.

Full support
Full support
No support
No support
User must explicitly enable this feature.

See also