/** * @param string|HtmlElement $element * * @return $this|self */ public function add($element) : self { if (is_string($element) && $element == '---') { $element = (new HtmlElement('<li>'))->addAttribute('role', 'separator')->addClass('divider'); } elseif (is_string($element)) { $element = (new HtmlElement('<li>'))->setContent($element)->addClass('dropdown-header'); } else { $element = (new HtmlContainer('<li>'))->add($element); } $this->ul->add($element); return $this; }