Window: scheduler property
The scheduler read-only property of the Window interface is the entry point for using the Prioritized Task Scheduling API.
It returns a Scheduler object instance containing postTask() and yield() methods that can be used to schedule prioritized tasks.
Value
A Scheduler.
Examples
The code below shows a very basic use of the property and its associated interface. It demonstrates how to check that the property exists and then posts a task that returns a promise.
js
// Check if the prioritized task API is supported
if ("scheduler" in window) {
// Callback function - "the task"
const myTask = () => "Task 1: user-visible";
// Post task with default priority: 'user-visible' (no other options)
// When the task resolves, Promise.then() logs the result.
window.scheduler
.postTask(myTask)
// Handle resolved value
.then((taskResult) => console.log(`${taskResult}`))
// Handle error or abort
.catch((error) => console.log(`Error: ${error}`));
} else {
console.log("Feature: NOT Supported");
}
For comprehensive example code showing to use the API see Prioritized Task Scheduling API > Examples.