maybe

menu.js

define(function (require, exports, module) {
  var $ = Zepto;

  /**
   * slideToggle
   * @param element
   * @param display
   */
  var slideToggleTrans = function (element, display, callback) { //  display表示默认更多展开元素是显示状态还是隐藏
    element.on("click", function () {
      display = !display;

      var rel = $(this).attr("data-rel"), eleMore = $("#" + rel);

      eleMore.length > 0 && (eleMore.style.height = display ? (function () {
        var height = 0;
        Array.prototype.slice.call(eleMore.childNodes).forEach(function (child) {
          if (child.nodeType === 1) {
            var oStyle = window.getComputedStyle(child);
            height = child.clientHeight + (parseInt(oStyle.borderTopWidth) || 0) + (parseInt(oStyle.borderBottomWidth) || 0);
          }
        });
        return height;
      })() + "px" : "0px");

      callback.call(element, eleMore, display);

    });

  };


  (function ($) {
    $.fn.slideDown = function (duration) {
      // get old position to restore it then
      var position = this.css('position');

      // show element if it is hidden (it is needed if display is none)
      this.show();

      // place it so it displays as usually but hidden
      this.css({
        position: 'absolute',
        visibility: 'hidden'
      });

      // get naturally height
      var height = this.height();

      // set initial css for animation
      this.css({
        position: position,
        visibility: 'visible',
        overflow: 'hidden',
        height: 0
      });

      // animate to gotten height
      this.animate({
        height: height
      }, duration);
    };
  })(Zepto);

/*  $(function () {
    var menuParentItems = $(".am-menu .am-parent > a");

    menuParentItems.on("click", function (e) {
      e.preventDefault();
      var subMenu = $(this).next(".am-menu-sub");
      var parentItem = $(this).parent(".am-parent");
      parentItem.toggleClass("am-active").find(".am-active").removeClass("am-active");
      parentItem.siblings().removeClass("am-active");

    });
  });*/
});