Get a vendor prefixed event name based on browser support

get-supported-css-event-name.js

// http://stackoverflow.com/a/1026087
function capitalizeFirstLetter(string) {
  return (typeof string === 'string' || string instanceof String) ?
    string.charAt(0).toUpperCase() + string.slice(1) :
    false;
}

/**
 * Enum for css event group values.
 * @readonly
 * @enum {string}
 */
var cssEventGroups = {
  animation: 'animation',
  transition: 'transition'
};

/**
 * Enum for css event type values.
 * @readonly
 * @enum {string}
 */
var cssEventTypes = {
  start: 'start',
  end: 'end',
  iteration: 'iteration'
};

/**
 * Get the vendor prefixed event name based on browser support.
 * Note: cssEventTypes.start and cssEventTypes.iteration only work with cssEventGroups.animation
 * @see {@link http://callmenick.com/post/listen-for-css-animation-events-with-javascript} for further information
 * @example
 * // returns one of the following "animationend" "mozAnimationEnd" "webkitAnimationEnd" "oAnimationEnd" "MSAnimationEnd"
 * getSupportedCssEventName(cssEventGroups.animation, cssEventTypes.end);
 * @enum {cssEventGroups} eventGroup - The group which the type belongs to
 * @enum {cssEventTypes} eventType - The type of event
 * @returns {string|boolean} The event name based on browser support or false if none found
 */
function getSupportedCssEventName(eventGroup, eventType) {
  var body = document.body || document.documentElement,
      style = body.style,
      domPrefixes = ['Moz', 'Webkit', 'O', 'ms'],
      eventPrefixes = ['moz', 'webkit', 'o', 'MS'],
      eventName = eventGroup + capitalizeFirstLetter(eventType);
  if (typeof style[eventGroup] === 'string') {
    return eventName.toLowerCase();
  }
  eventGroup = capitalizeFirstLetter(eventGroup);
  eventName = capitalizeFirstLetter(eventName);
  for (var i=0; i<domPrefixes.length; i++) {
    if (typeof style[domPrefixes[i]+eventGroup] === 'string') {
      return eventPrefixes[i]+eventName;
    }
  }
  return false;
}