{@inhertdoc}
Overrides RouteEnhancerInterface::enhance
public function enhance(array $defaults, Request $request) {
if (empty($defaults['_controller']) && !empty($defaults['_form']) && $this->negotiation
->getContentType($request) === 'html') {
$defaults['_controller'] = '\\Drupal\\Core\\Controller\\HtmlFormController::content';
}
return $defaults;
}