RestManager::processMethodRequest

public function processMethodRequest(array $params, $start, CRestServer $restServer)
{
	$start = intval($start);
	$this->initialize($restServer, $start);

	$errorCollection = new ErrorCollection();
	$method = $restServer->getMethod();
	$methodData = ScopeManager::getInstance()->getMethodInfo($method);

	$request = new BitrixMainHttpRequest(
		Context::getCurrent()->getServer(),
		['action' => $methodData['method']],
		[], [], []
	);
	$router = new EngineRouter($request);

	/** @var Controller $controller */
	[$controller, $action] = Resolver::getControllerAndAction(
		$router->getVendor(),
		$router->getModule(),
		$router->getAction(),
		Controller::SCOPE_REST
	);
	if (!$controller)
	{
		throw new RestException("Unknown {$method}. There is not controller in module {$router->getModule()}");
	}

	$this->calculateTotalCount = true;
	if ((int)$start === self::DONT_CALCULATE_COUNT)
	{
		$this->calculateTotalCount = false;
	}

	$autoWirings = $this->getAutoWirings();

	$this->registerAutoWirings($autoWirings);
	$result = $controller->run($action, [$params, ['__restServer' => $restServer, '__calculateTotalCount' => $this->calculateTotalCount]]);
	$this->unRegisterAutoWirings($autoWirings);

	if ($result instanceof EngineResponseFile)
	{
		return $result->send();
	}

	if ($result instanceof HttpResponse)
	{
		if ($result instanceof Errorable)
		{
			$errorCollection->add($result->getErrors());
		}

		$result = $result->getContent();
	}

	if ($result instanceof RestException)
	{
		throw $result;
	}

	if ($result === null)
	{
		$errorCollection->add($controller->getErrors());
		if (!$errorCollection->isEmpty())
		{
			throw $this->createExceptionFromErrors($errorCollection->toArray());
		}
	}

	return $this->processData($result);
}