Link::class, ]; private static $has_many = [ 'ManyCompanyWebSiteLink' => Link::class . '.Owner', ]; private static array $owns = [ 'CompanyWebSiteLink', 'ManyCompanyWebSiteLink', ]; private static array $cascade_deletes = [ 'CompanyWebSiteLink', 'ManyCompanyWebSiteLink', ]; private static array $cascade_duplicates = [ 'CompanyWebSiteLink', 'ManyCompanyWebSiteLink', ]; protected function updateCMSFields(FieldList $fields) { $fields->dataFieldByName('CompanyWebSiteLink')->setAllowedTypes([ExternalLink::class]); } }