Function getClass

02.Components/Part-2/js/vue.js:1295–1301

* For IE9 compat: when both class and :class are present * getAttribute('class') returns wrong value... * * @param {Element} el * @return {String}

(el)

   */

  function getClass(el) {
    var classname = el.className;
    if (typeof classname === 'object') {
      classname = classname.baseVal || '';
    }
    return classname;
  }

  /**
   * In IE9, setAttribute('class') will result in empty class