Update the defaults based on its own data and the request.
array $defaults the getRouteDefaults array:
array the modified defaults. Each enhancer MUST return the $defaults but may add or remove values
Overrides RouteEnhancerInterface::enhance
public function enhance(array $defaults, Request $request) {
if (empty($defaults['_controller']) && !empty($defaults['_entity_form']) && $this->negotiation
->getContentType($request) === 'html') {
$defaults['_controller'] = '\\Drupal\\Core\\Entity\\HtmlEntityFormController::content';
}
return $defaults;
}