private function loadFilterForm() { // get categories $groups = BackendAddressesModel::getAllGroupsTree(); //$groups = array('') + $groups; // multiple categories? if (count($groups) > 1) { // create form $frm = new BackendForm('filter', null, 'get', false); // create element $frm->addDropdown('group', $groups, $this->groupId); // $frm->getField('category')->setDefaultElement(''); // parse the form $frm->parse($this->tpl); } // parse category if (!empty($this->category)) { $this->tpl->assign('filterGroup', $this->group); } }