core/homeassistant/components/mqtt_eventstream.py

107 lines
3.8 KiB
Python

"""
Connect two Home Assistant instances via MQTT.
For more details about this component, please refer to the documentation at
https://home-assistant.io/components/mqtt_eventstream/
"""
import json
import voluptuous as vol
import homeassistant.loader as loader
from homeassistant.components.mqtt import (
valid_publish_topic, valid_subscribe_topic)
from homeassistant.const import (
ATTR_SERVICE_DATA, EVENT_CALL_SERVICE, EVENT_SERVICE_EXECUTED,
EVENT_STATE_CHANGED, EVENT_TIME_CHANGED, MATCH_ALL)
from homeassistant.core import EventOrigin, State
from homeassistant.remote import JSONEncoder
DOMAIN = "mqtt_eventstream"
DEPENDENCIES = ['mqtt']
CONF_PUBLISH_TOPIC = 'publish_topic'
CONF_SUBSCRIBE_TOPIC = 'subscribe_topic'
CONFIG_SCHEMA = vol.Schema({
DOMAIN: vol.Schema({
vol.Optional(CONF_PUBLISH_TOPIC): valid_publish_topic,
vol.Optional(CONF_SUBSCRIBE_TOPIC): valid_subscribe_topic,
}),
}, extra=vol.ALLOW_EXTRA)
def setup(hass, config):
"""Setup the MQTT eventstream component."""
mqtt = loader.get_component('mqtt')
conf = config.get(DOMAIN, {})
pub_topic = conf.get(CONF_PUBLISH_TOPIC)
sub_topic = conf.get(CONF_SUBSCRIBE_TOPIC)
def _event_publisher(event):
"""Handle events by publishing them on the MQTT queue."""
if event.origin != EventOrigin.local:
return
if event.event_type == EVENT_TIME_CHANGED:
return
# Filter out the events that were triggered by publishing
# to the MQTT topic, or you will end up in an infinite loop.
if event.event_type == EVENT_CALL_SERVICE:
if (
event.data.get('domain') == mqtt.DOMAIN and
event.data.get('service') == mqtt.SERVICE_PUBLISH and
event.data[ATTR_SERVICE_DATA].get('topic') == pub_topic
):
return
# Filter out all the "event service executed" events because they
# are only used internally by core as callbacks for blocking
# during the interval while a service is being executed.
# They will serve no purpose to the external system,
# and thus are unnecessary traffic.
# And at any rate it would cause an infinite loop to publish them
# because publishing to an MQTT topic itself triggers one.
if event.event_type == EVENT_SERVICE_EXECUTED:
return
event_info = {'event_type': event.event_type, 'event_data': event.data}
msg = json.dumps(event_info, cls=JSONEncoder)
mqtt.publish(hass, pub_topic, msg)
# Only listen for local events if you are going to publish them.
if pub_topic:
hass.bus.listen(MATCH_ALL, _event_publisher)
# Process events from a remote server that are received on a queue.
def _event_receiver(topic, payload, qos):
"""Receive events published by and fire them on this hass instance."""
event = json.loads(payload)
event_type = event.get('event_type')
event_data = event.get('event_data')
# Special case handling for event STATE_CHANGED
# We will try to convert state dicts back to State objects
# Copied over from the _handle_api_post_events_event method
# of the api component.
if event_type == EVENT_STATE_CHANGED and event_data:
for key in ('old_state', 'new_state'):
state = State.from_dict(event_data.get(key))
if state:
event_data[key] = state
hass.bus.fire(
event_type,
event_data=event_data,
origin=EventOrigin.remote
)
# Only subscribe if you specified a topic.
if sub_topic:
mqtt.subscribe(hass, sub_topic, _event_receiver)
hass.states.set('{domain}.initialized'.format(domain=DOMAIN), True)
return True