sob

Scheduled on Browser

This is a zero dependencies utility to manage, in a simple and fully cross browser way, calls to requestAnimationFrame and requestIdleCallback.

New in version 0.1.0 the ability to schedule regular timeouts and intervals only when the tab is visible, saving operations for when the user needs them, as opposite to regardless.

Things this module does:

• it doesn't overload the requestAnimationFrame internal queue
• it schedules frame or idle passing extra arguments if specified, same as setTimeout and setInterval or setImmediate
• it avoids duplicated scheduling of the same callback with same optional arguments (TL;DR it does throttle)
• it makes cancelAnimationFrame and cancelIdleCallback consistent across browsers via clear method and for both scheduled queue and currently executed one
• it provides a similar requestIdleCallback mechanism for every browser
• it schedules timeouts and intervals executed only when the browser is visible, ensuring no duplicated callbacks are executed once the visibility is back

API

Following all methods provided by the object returned via this module.

const sob = require('sob');

sob.frame(fn) => uniqueId

Schedules fn for the next possible requestAnimationFrame without compromising performance. It returns a unique id usable to sob.clear(uid) if necessary.

sob.frame(fn, arg1, arg2, argN) => uniqueId

Similar to sob.frame(fn), it schedules fn for the next possible requestAnimationFrame invoking it with optionally provided arguments.

sob.idle(fn) => uniqueId

Schedules fn for the next possible requestIdleCallback without compromising performance. It returns a unique id usable to sob.clear(uid) if necessary.

sob.idle(fn, arg1, arg2, argN) => uniqueId

Similar to sob.idle(fn), it schedules fn for the next possible requestIdleCallback invoking it with optionally provided arguments.

sob.interval(fn, delay, arg0, arg1, ....argN)

Schedule an interval that won't occur while the page is not visible, eventually delaying it for when it is without invoking it many times consecutively.

sob.timeout(fn, delay, arg0, arg1, ....argN)

Schedule a timeout that won't occur while the page is not visible, eventually delaying it for when it is.

sob.clear(uniqueId)

Remove a previously scheduled frame, idle or timer through the previously returned unique id.

Examples

Following a basic example on how to use this module. The TL;DR verion is that whenever you'd like to use requestAnimationFrame or requestIdleCallback, you can use sob instead.

// simulating a requestAnimationFrame task
(function frameLoop() {
  sob.frame(frameLoop);
  document.body.textContent = new Date();
}());
 
// simulating a requestIdleCallback task
(function idleLoop() {
  sob.idle(idleLoop);
  console.log('idle');
}());