Set /status LWT topic only once

[zuckschwerdt]

I'm logging all my devices LWT topics (/status /presence /availability etc.) and a change in those topics usually indicates trouble (wifi lost, reboot).

It is surprising that WLED is repeatedly setting the /status LWT topic in normal operation.

The publishMqtt() function sets the LWT topic /status to "online". It is called from updateInterfaces() thus the LWT topic will be set with each change of parameters.

Was that a conscious design decision? Is there a technical or API reason?

Would you be open to a PR which moves

WLED/wled00/mqtt.cpp

Lines 177 to 179 in 25223c4

	strlcpy(subuf, mqttDeviceTopic, MQTT_MAX_TOPIC_LEN + 1);
	strcat_P(subuf, PSTR("/status"));
	mqtt->publish(subuf, 0, true, "online"); // retain message for a LWT

up a few lines into onMqttConnect() -- it's where other projects usually set the LWT.

[blazoncek]

Yes.