Getting mqtt topic from a message

[SmallerPond]

This might be a dumb question. I have a pretty simple modification of the mqtt_simple sample application on an nRF9160DK where I have subscribed to multiple topics. I see the inbound messages from those topics, but I can't find anywhere on the mqtt_client struct (or anywhere else) to get the topic whence came the message.  Obviously one of the processing layers must know the topic from which a message arrives since it knows to look at those specific topics, am I missing something?

[Sigurd Hellesvik]

Hi,

It is in a struct, just not trivial to follow it:

mqtt event callback -> mqtt_evt -> mqtt_publish_param -> mqtt_publish_message -> mqtt_topic -> mqtt_utf8

So try to add this to "case MQTT_EVT_PUBLISH":

printk("Topic: %s\n", evt->param.publish.message.topic.topic.utf8);

Regards,
Sigurd Hellesvik

[SmallerPond]

Thanks! Perfect!