样式名加前缀

vendor.js

function vendor(style) {
  if (!styles[style]) {
    prefixes.map(function (prefix) {
      return prefix
        ? prefix + style[0].toUpperCase() + style.slice(1)
        : style
    }).some(function (prefixedStyle) {
      if (elementStyle[prefixedStyle] !== void 0) {
        styles[style] = prefixedStyle
        return true
      }
    })
  }
  return styles[style] || null
}

var styles = {}
var prefixedEvents = {}
var prefixes = ['', 'Webkit', 'Moz', 'O', 'MS']
var evPrefixes = ['', 'webkit', 'moz', 'o', 'MS']
var elementStyle = document.createElement('div').style
var transitionEnds = {
  transition: 'transitionend',
  WebkitTransition: 'webkitTransitionEnd',
  MozTransition: 'transitionend',
  OTransition: 'oTransitionEnd'
}
var animationEnds = {
  animation: 'animationend',
  WebkitAnimation: 'webkitAnimationEnd',
  MozAnimation: 'animationend',
  OAnimation: 'oAnimationEnd'
}

function transitionEnd() {
  return transitionEnds[vendor('transition')] || transitionEnds.transition
}

function animationEnd() {
  return animationEnds[vendor('animation')] || animationEnds.animation
}

/**
 * type  event type, animationEnd, transitionStart, etc.
 *
 * @return {String} prefixed event type
 */
function basePrefixEvent(type) {
  var result = type.toLowerCase()
  evPrefixes.map(function (pfx) {
    if (!pfx) {
      return type.toLowerCase()
    }
    return pfx + type[0].toUpperCase() + type.slice(1)
  }).some(function (prefixed) {
    var style = vendor( type.replace(/[A-Z][a-z]*$/, '') )
    var re = new RegExp('^' + style, 'i')
    var isMatch = re.test(prefixed)
    if (isMatch) {
      result = prefixed
      return true
    }
  })
  return result
}

function prefixEvent(type) {
  var result = prefixedEvents[type]
  if (!result) {
    prefixedEvents[type] = basePrefixEvent(type)
  }
  return prefixedEvents[type]
}