Thread CoAP Response Handler - How to get POST response code

Question

My project is based on the Thread cloud coap client example. I would like to know if my CoAP POSTs to the cloud are successful. 
 I added a "post_response_handler" to the SendRequest: 
 //error = otCoapSendRequest(p_instance, p_request, &message_info, NULL, NULL);
 error = otCoapSendRequest(p_instance, p_request, &message_info, post_response_handler, NULL); //added response handler 
 The post_response_handler is firing after a successful post, but I can't figure out how to extract the coap response code (typedef enum otCoapCode) from the message. Here's what I have so far. Any help would be greatly appreciated. 
 static void post_response_handler( void * p_context,
 otCoapHeader * p_header,
 otMessage * p_message,
 const otMessageInfo * p_message_info,
 otError result)
{
 (void)p_context;
 (void)p_header;
 
 // restore the polling period back to initial slow value
 UNUSED_VARIABLE(poll_period_restore(thread_ot_instance_get()));

 UNUSED_VARIABLE(otMessageRead(p_message,
 otMessageGetOffset(p_message),
 &???????.???????,
 sizeof(?????????.???????))
 );
 
 NRF_LOG_INFO("CoAP code: %d
", &????????.???????);
 
}

Lukasz Duda · Accepted Answer

Hello Rob, 
 CoAP Response code is embedded to CoAP Header of the message. You can easily pull it out using following function: otCoapCode otCoapHeaderGetCode(const otCoapHeader *aHeader) 
 As you can see, variable of otCoapHeader type is already provided to the application response handler. 
 Specifically for your example, the last line of the code would look like this: 
 NRF_LOG_INFO("CoAP code: %d
", otCoapHeaderGetCode(p_header)); 
 You can read more about this function here .

Thread CoAP Response Handler - How to get POST response code

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