drupal/core/misc/debounce.js

37 lines
1.1 KiB
JavaScript

/**
* 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 attache 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} callback
* 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.
*/
Drupal.debounce = function (callback, wait) {
"use strict";
var timeout, result;
return function () {
var context = this;
var args = arguments;
var later = function () {
timeout = null;
result = callback.apply(context, args);
};
window.clearTimeout(timeout);
timeout = window.setTimeout(later, wait);
return result;
};
};