Fields()->dataFieldByName('Subsite'); if($grid) { $grid->getConfig()->removeComponentsByType('GridFieldDetailForm'); $grid->getConfig()->addComponent(new GridFieldSubsiteDetailForm()); } return $form; } public function getResponseNegotiator() { $negotiator = parent::getResponseNegotiator(); $self = $this; // Register a new callback $negotiator->setCallback('SubsiteList', function() use(&$self) { return $self->SubsiteList(); }); return $negotiator; } public function SubsiteList() { return $this->renderWith('SubsiteList'); } }