/**
* @file
* Adapted from underscore.js with the addition Drupal namespace.
*/
/**
* Limits the invocations of a function in a given time frame.
*
* The debounce function wrapper should be used sparingly. One clear use case
* is limiting the invocation of a callback attached to the window resize event.
*
* Before using the debounce function wrapper, consider first whether the
* callback could be attached to an event that fires less frequently or if the
* function can be written in such a way that it is only invoked under specific
* conditions.
*
* @param {function} func
* The function to be invoked.
* @param {number} wait
* The time period within which the callback function should only be
* invoked once. For example if the wait period is 250ms, then the callback
* will only be called at most 4 times per second.
* @param {bool} immediate
* Whether we wait at the beginning or end to execute the function.
*
* @return {function}
* The debounced function.
*/
Drupal.debounce = function(func, wait, immediate) {
let timeout;
let result;
return function(...args) {
const context = this;
const later = function() {
timeout = null;
if (!immediate) {
result = func.apply(context, args);
}
};
const callNow = immediate && !timeout;
clearTimeout(timeout);
timeout = setTimeout(later, wait);
if (callNow) {
result = func.apply(context, args);
}
return result;
};
};