徐辰

Look at [MQTTClient.cpp:146](https://github.com/256dpi/arduino-mqtt/blob/82a9f3441d6317fe53c705a9226f7d1d57e1d42f/src/MQTTClient.cpp#L146) ``` str_payload = String((const char *)message.payload); ``` It doesn't look like that the library supports receiving binary.

Hi, @cy6erGn0m, I'was trying to make Ktor work with Logstash, which supports log in JSON format, so user can add additional key/values along with normal log messages. I checked out...

It's not about MDC actually, what I wanted is to log in JSON format and add some customized properties, with Fluentd/Elasticsearch I can dig into logs easily. Logback has a...

@AndreasVolkmann no it doesn't work, what I was trying to do is to log in JSON format with additional customizable properties/values, but seems Ktor's CallLogging cannot do.

Could you please explain more about the purpose of these callback functions? What's their use cases?

> @windoze the primary aim to add this callback as parameter was to register the details about which notebook is using these features. This helps in generating end to end...

> @windoze what if someone needs to store the feature usage in a separate DB to monitor it, or some other events we want to trigger based on the feature...

> We can add something like a `reason` parameter to tell the callback why it got called, so it can do specific things for specific reason. For ad-hoc usage, I...

> Got it. So, it would be better to place the callback in the class level instead of function level. Let me change the code accordingly then. > > Thanks...

> @windoze the params would be sent in function level. Or else we cannot send the variable payload. Then I'll suggest to thoroughly review the requirement and the use case...