in templates/ydotm/bootstrap3.js [1624:1646]
ScrollSpy.prototype.activate = function (target) {
this.activeTarget = target
$(this.selector)
.parentsUntil(this.options.target, '.active')
.removeClass('active')
var selector = this.selector +
'[data-target="' + target + '"],' +
this.selector + '[href="' + target + '"]'
var active = $(selector)
.parents('li')
.addClass('active')
if (active.parent('.dropdown-menu').length) {
active = active
.closest('li.dropdown')
.addClass('active')
}
active.trigger('activate.bs.scrollspy')
}