The TaskPriorityChangeEvent is the interface for the prioritychange event.

TaskPriorityChangeEvent()

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

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.

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

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.

// 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.

• prioritychange event