Field::listAction

public function listAction(?int $presetId): array
{
	if (!WebForm\Manager::checkReadPermission())
	{
		$this->addError(new Main\Error(Loc::getMessage('CRM_CONTROLLER_FORM_FIELD_ACCESS_DENIED'), 510));
		return [];
	}

	return [
		'tree' => WebForm\EntityFieldProvider::getFieldsTree([], $presetId),
	];
}