util.js

/**
 * --------------------------------------------------------------------------
 * Bootstrap (v4.3.1): util.js
 * Licensed under MIT (https://github.com/twbs/bootstrap/blob/master/LICENSE)
 * --------------------------------------------------------------------------
 */

/**
 * ------------------------------------------------------------------------
 * Private TransitionEnd Helpers
 * ------------------------------------------------------------------------
 */

const TRANSITION_END = 'transitionend'
const MAX_UID = 1000000
const MILLISECONDS_MULTIPLIER = 1000

// Shoutout AngusCroll (https://goo.gl/pxwQGp)
function toType(obj) {
  return {}.toString.call(obj).match(/\s([a-z]+)/i)[1].toLowerCase()
}

const Util = {

  TRANSITION_END: 'bsTransitionEnd',

  getUID(prefix) {
    do {
      // eslint-disable-next-line no-bitwise
      prefix += ~~(Math.random() * MAX_UID) // "~~" acts like a faster Math.floor() here
    } while (document.getElementById(prefix))
    return prefix
  },

  getSelectorFromElement(element) {
    let selector = element.getAttribute('data-target')

    if (!selector || selector === '#') {
      const hrefAttr = element.getAttribute('href')
      selector = hrefAttr && hrefAttr !== '#' ? hrefAttr.trim() : ''
    }

    try {
      return document.querySelector(selector) ? selector : null
    } catch (err) {
      return null
    }
  },

  getTransitionDurationFromElement(element) {
    if (!element) {
      return 0
    }

    // Get transition-duration of the element
    let transitionDuration = window.getComputedStyle(element).transitionDuration
    let transitionDelay = window.getComputedStyle(element).transitionDelay

    const floatTransitionDuration = parseFloat(transitionDuration)
    const floatTransitionDelay = parseFloat(transitionDelay)

    // Return 0 if element or transition duration is not found
    if (!floatTransitionDuration && !floatTransitionDelay) {
      return 0
    }

    // If multiple durations are defined, take the first
    transitionDuration = transitionDuration.split(',')[0]
    transitionDelay = transitionDelay.split(',')[0]