Add a status callback for MQTT subscriptions
1 min read
Integrations that use MQTT might need to wait for a subscription to complete before they initiate actions. The default behavior is that a subscription is queued and debounced, so callers usually do not wait for broker confirmation. Some integrations must guarantee that the broker finished the subscription.
The new mqtt.async_on_subscribe_done helper can be used to monitor MQTT subscriptions, to allow doing additional tasks.
Make sure the same QoS is used as in the MQTT subscription.
Example:
Python
from homeassistant.components import mqtt
async def async_setup_entry(hass: HomeAssistant, entry: ConfigEntry) -> bool:
"""Setup integration MQTT subscription monitoring."""
def _on_subscribe_status() -> None:
"""Handle subscription ready signal."""
# Do stuff
# Handle subscription ready status update
await mqtt.async_on_subscribe_done(
hass,
"myintegration/status",
qos=1,
on_subscribe_status=_on_subscribe_status,
)
# Do stuff