Throttling Javascript events. Throttle dom events or any other events.

throttle.js

/**
 * Throttle function to reduce number of events
 * coming from event stream
 * 
 * Useful for reducing number of updates coming from 
 * mousemove events or such.
 * 
 * @param time - in miliseconds
 * @param callback - event callback see example below.
 *
 * EXAMPLE:
 * document.addEventListener('mousemove', throttle(100, (event) => {
 *     // Process mousemove event every 100ms
 * }));
 *
 * @author github.com/SandroRybarik
 * @license MIT
 */
const throttle = (time, callback) => {
    let waiting = false;

    return (event) => {
        if (waiting) {
            return; // discard event
        }

        if (!waiting) {
            callback(event);
            waiting = true;
            setTimeout(() => {
                waiting = false;
            }, time);
        }
    }
}