bool IotShadowClient::SubscribeToNamedShadowDeltaUpdatedEvents()

in shadow/source/IotShadowClient.cpp [733:785]
49 lines of code
3 McCabe index (conditional complexity)

        bool IotShadowClient::SubscribeToNamedShadowDeltaUpdatedEvents(
            const Aws::Iotshadow::NamedShadowDeltaUpdatedSubscriptionRequest &request,
            Aws::Crt::Mqtt::QOS qos,
            const OnSubscribeToNamedShadowDeltaUpdatedEventsResponse &handler,
            const OnSubscribeComplete &onSubAck)
        {
            (void)request;
            auto onSubscribeComplete = [handler, onSubAck](
                                           Aws::Crt::Mqtt::MqttConnection &,
                                           uint16_t,
                                           const Aws::Crt::String &topic,
                                           Aws::Crt::Mqtt::QOS,
                                           int errorCode) {
                (void)topic;
                if (errorCode)
                {
                    handler(nullptr, errorCode);
                }

                if (onSubAck)
                {
                    onSubAck(errorCode);
                }
            };

            auto onSubscribePublish =
                [handler](
                    Aws::Crt::Mqtt::MqttConnection &, const Aws::Crt::String &, const Aws::Crt::ByteBuf &payload) {
                    Aws::Crt::String objectStr(reinterpret_cast<char *>(payload.buffer), payload.len);
                    Aws::Crt::JsonObject jsonObject(objectStr);
                    Aws::Iotshadow::ShadowDeltaUpdatedEvent response(jsonObject);
                    handler(&response, AWS_ERROR_SUCCESS);
                };

            Aws::Crt::StringStream subscribeTopicSStr;
            subscribeTopicSStr << "$aws"
                               << "/"
                               << "things"
                               << "/" << *request.ThingName << "/"
                               << "shadow"
                               << "/"
                               << "name"
                               << "/" << *request.ShadowName << "/"
                               << "update"
                               << "/"
                               << "delta";

            return m_connection->Subscribe(
                       subscribeTopicSStr.str().c_str(),
                       qos,
                       std::move(onSubscribePublish),
                       std::move(onSubscribeComplete)) != 0;
        }