EventBus: return function to unlisten

homeassistant/components/automation/state.py

@@ -7,8 +7,7 @@ at https://home-assistant.io/components/automation/#state-trigger
 import voluptuous as vol
 
 import homeassistant.util.dt as dt_util
-from homeassistant.const import (
+from homeassistant.const import MATCH_ALL, CONF_PLATFORM
-    EVENT_STATE_CHANGED, EVENT_TIME_CHANGED, MATCH_ALL, CONF_PLATFORM)
 from homeassistant.helpers.event import track_state_change, track_point_in_time
 import homeassistant.helpers.config_validation as cv
 
@@ -60,23 +59,20 @@ def trigger(hass, config, action):
 
         def state_for_listener(now):
             """Fire on state changes after a delay and calls action."""
-            hass.bus.remove_listener(
+            remove_state_for_cancel()
-                EVENT_STATE_CHANGED, attached_state_for_cancel)
             call_action()
 
         def state_for_cancel_listener(entity, inner_from_s, inner_to_s):
             """Fire on changes and cancel for listener if changed."""
             if inner_to_s.state == to_s.state:
                 return
-            hass.bus.remove_listener(EVENT_TIME_CHANGED,
+            remove_state_for_listener()
-                                     attached_state_for_listener)
+            remove_state_for_cancel()
-            hass.bus.remove_listener(EVENT_STATE_CHANGED,
-                                     attached_state_for_cancel)
 
-        attached_state_for_listener = track_point_in_time(
+        remove_state_for_listener = track_point_in_time(
             hass, state_for_listener, dt_util.utcnow() + time_delta)
 
-        attached_state_for_cancel = track_state_change(
+        remove_state_for_cancel = track_state_change(
             hass, entity, state_for_cancel_listener)
 
     track_state_change(

homeassistant/components/cover/demo.py

@@ -5,7 +5,6 @@ For more details about this platform, please refer to the documentation
 https://home-assistant.io/components/demo/
 """
 from homeassistant.components.cover import CoverDevice
-from homeassistant.const import EVENT_TIME_CHANGED
 from homeassistant.helpers.event import track_utc_time_change
 
 
@@ -32,8 +31,8 @@ class DemoCover(CoverDevice):
         self._tilt_position = tilt_position
         self._closing = True
         self._closing_tilt = True
-        self._listener_cover = None
+        self._unsub_listener_cover = None
-        self._listener_cover_tilt = None
+        self._unsub_listener_cover_tilt = None
 
     @property
     def name(self):
@@ -120,10 +119,9 @@ class DemoCover(CoverDevice):
         """Stop the cover."""
         if self._position is None:
             return
-        if self._listener_cover is not None:
+        if self._unsub_listener_cover is not None:
-            self.hass.bus.remove_listener(EVENT_TIME_CHANGED,
+            self._unsub_listener_cover()
-                                          self._listener_cover)
+            self._unsub_listener_cover = None
-            self._listener_cover = None
             self._set_position = None
 
     def stop_cover_tilt(self, **kwargs):
@@ -131,16 +129,15 @@ class DemoCover(CoverDevice):
         if self._tilt_position is None:
             return
 
-        if self._listener_cover_tilt is not None:
+        if self._unsub_listener_cover_tilt is not None:
-            self.hass.bus.remove_listener(EVENT_TIME_CHANGED,
+            self._unsub_listener_cover_tilt()
-                                          self._listener_cover_tilt)
+            self._unsub_listener_cover_tilt = None
-            self._listener_cover_tilt = None
             self._set_tilt_position = None
 
     def _listen_cover(self):
         """Listen for changes in cover."""
-        if self._listener_cover is None:
+        if self._unsub_listener_cover is None:
-            self._listener_cover = track_utc_time_change(
+            self._unsub_listener_cover = track_utc_time_change(
                 self.hass, self._time_changed_cover)
 
     def _time_changed_cover(self, now):
@@ -156,8 +153,8 @@ class DemoCover(CoverDevice):
 
     def _listen_cover_tilt(self):
         """Listen for changes in cover tilt."""
-        if self._listener_cover_tilt is None:
+        if self._unsub_listener_cover_tilt is None:
-            self._listener_cover_tilt = track_utc_time_change(
+            self._unsub_listener_cover_tilt = track_utc_time_change(
                 self.hass, self._time_changed_cover_tilt)
 
     def _time_changed_cover_tilt(self, now):

homeassistant/components/group.py

@@ -175,6 +175,7 @@ class Group(Entity):
         self.group_off = None
         self._assumed_state = False
         self._lock = threading.Lock()
+        self._unsub_state_changed = None
 
         if entity_ids is not None:
             self.update_tracked_entity_ids(entity_ids)
@@ -236,15 +237,16 @@ class Group(Entity):
 
     def start(self):
         """Start tracking members."""
-        track_state_change(
+        self._unsub_state_changed = track_state_change(
             self.hass, self.tracking, self._state_changed_listener)
 
     def stop(self):
         """Unregister the group from Home Assistant."""
         self.hass.states.remove(self.entity_id)
 
-        self.hass.bus.remove_listener(
+        if self._unsub_state_changed:
-            ha.EVENT_STATE_CHANGED, self._state_changed_listener)
+            self._unsub_state_changed()
+            self._unsub_state_changed = None
 
     def update(self):
         """Query all members and determine current group state."""

homeassistant/components/mqtt/__init__.py

@@ -170,9 +170,14 @@ def subscribe(hass, topic, callback, qos=DEFAULT_QOS):
             callback(event.data[ATTR_TOPIC], event.data[ATTR_PAYLOAD],
                      event.data[ATTR_QOS])
 
-    hass.bus.listen(EVENT_MQTT_MESSAGE_RECEIVED, mqtt_topic_subscriber)
+    remove = hass.bus.listen(EVENT_MQTT_MESSAGE_RECEIVED,
+                             mqtt_topic_subscriber)
+
+    # Future: track subscriber count and unsubscribe in remove
     MQTT_CLIENT.subscribe(topic, qos)
 
+    return remove
+
 
 def _setup_server(hass, config):
     """Try to start embedded MQTT broker."""

homeassistant/components/rollershutter/demo.py

@@ -5,7 +5,6 @@ For more details about this platform, please refer to the documentation
 https://home-assistant.io/components/demo/
 """
 from homeassistant.components.rollershutter import RollershutterDevice
-from homeassistant.const import EVENT_TIME_CHANGED
 from homeassistant.helpers.event import track_utc_time_change
 
 
@@ -27,7 +26,7 @@ class DemoRollershutter(RollershutterDevice):
         self._name = name
         self._position = position
         self._moving_up = True
-        self._listener = None
+        self._unsub_listener = None
 
     @property
     def name(self):
@@ -70,15 +69,15 @@ class DemoRollershutter(RollershutterDevice):
 
     def stop(self, **kwargs):
         """Stop the roller shutter."""
-        if self._listener is not None:
+        if self._unsub_listener is not None:
-            self.hass.bus.remove_listener(EVENT_TIME_CHANGED, self._listener)
+            self._unsub_listener()
-            self._listener = None
+            self._unsub_listener = None
 
     def _listen(self):
         """Listen for changes."""
-        if self._listener is None:
+        if self._unsub_listener is None:
-            self._listener = track_utc_time_change(self.hass,
+            self._unsub_listener = track_utc_time_change(self.hass,
-                                                   self._time_changed)
+                                                         self._time_changed)
 
     def _time_changed(self, now):
         """Track time changes."""

homeassistant/core.py

@@ -297,6 +297,12 @@ class EventBus(object):
             else:
                 self._listeners[event_type] = [listener]
 
+        def remove_listener():
+            """Remove the listener."""
+            self.remove_listener(event_type, listener)
+
+        return remove_listener
+
     def listen_once(self, event_type, listener):
         """Listen once for event of a specific type.
 

homeassistant/helpers/event.py

@@ -14,8 +14,7 @@ def track_state_change(hass, entity_ids, action, from_state=None,
     entity_ids, from_state and to_state can be string or list.
     Use list to match multiple.
 
-    Returns the listener that listens on the bus for EVENT_STATE_CHANGED.
+    Returns a function that can be called to remove the listener.
-    Pass the return value into hass.bus.remove_listener to remove it.
     """
     from_state = _process_state_match(from_state)
     to_state = _process_state_match(to_state)
@@ -50,9 +49,7 @@ def track_state_change(hass, entity_ids, action, from_state=None,
                    event.data.get('old_state'),
                    event.data.get('new_state'))
 
-    hass.bus.listen(EVENT_STATE_CHANGED, state_change_listener)
+    return hass.bus.listen(EVENT_STATE_CHANGED, state_change_listener)
-
-    return state_change_listener
 
 
 def track_point_in_time(hass, action, point_in_time):
@@ -77,23 +74,20 @@ def track_point_in_utc_time(hass, action, point_in_time):
         """Listen for matching time_changed events."""
         now = event.data[ATTR_NOW]
 
-        if now >= point_in_time and \
+        if now < point_in_time or hasattr(point_in_time_listener, 'run'):
-           not hasattr(point_in_time_listener, 'run'):
+            return
 
-            # Set variable so that we will never run twice.
+        # Set variable so that we will never run twice.
-            # Because the event bus might have to wait till a thread comes
+        # Because the event bus might have to wait till a thread comes
-            # available to execute this listener it might occur that the
+        # available to execute this listener it might occur that the
-            # listener gets lined up twice to be executed. This will make
+        # listener gets lined up twice to be executed. This will make
-            # sure the second time it does nothing.
+        # sure the second time it does nothing.
-            point_in_time_listener.run = True
+        point_in_time_listener.run = True
+        remove()
+        action(now)
 
-            hass.bus.remove_listener(EVENT_TIME_CHANGED,
+    remove = hass.bus.listen(EVENT_TIME_CHANGED, point_in_time_listener)
-                                     point_in_time_listener)
+    return remove
-
-            action(now)
-
-    hass.bus.listen(EVENT_TIME_CHANGED, point_in_time_listener)
-    return point_in_time_listener
 
 
 def track_sunrise(hass, action, offset=None):
@@ -112,10 +106,18 @@ def track_sunrise(hass, action, offset=None):
 
     def sunrise_automation_listener(now):
         """Called when it's time for action."""
+        nonlocal remove
         track_point_in_utc_time(hass, sunrise_automation_listener, next_rise())
         action()
 
-    track_point_in_utc_time(hass, sunrise_automation_listener, next_rise())
+    remove = track_point_in_utc_time(hass, sunrise_automation_listener,
+                                     next_rise())
+
+    def remove_listener():
+        """Remove sunrise listener."""
+        remove()
+
+    return remove_listener
 
 
 def track_sunset(hass, action, offset=None):
@@ -134,10 +136,19 @@ def track_sunset(hass, action, offset=None):
 
     def sunset_automation_listener(now):
         """Called when it's time for action."""
-        track_point_in_utc_time(hass, sunset_automation_listener, next_set())
+        nonlocal remove
+        remove = track_point_in_utc_time(hass, sunset_automation_listener,
+                                         next_set())
         action()
 
-    track_point_in_utc_time(hass, sunset_automation_listener, next_set())
+    remove = track_point_in_utc_time(hass, sunset_automation_listener,
+                                     next_set())
+
+    def remove_listener():
+        """Remove sunset listener."""
+        remove()
+
+    return remove_listener
 
 
 # pylint: disable=too-many-arguments
@@ -152,8 +163,7 @@ def track_utc_time_change(hass, action, year=None, month=None, day=None,
             """Fire every time event that comes in."""
             action(event.data[ATTR_NOW])
 
-        hass.bus.listen(EVENT_TIME_CHANGED, time_change_listener)
+        return hass.bus.listen(EVENT_TIME_CHANGED, time_change_listener)
-        return time_change_listener
 
     pmp = _process_time_match
     year, month, day = pmp(year), pmp(month), pmp(day)
@@ -178,8 +188,7 @@ def track_utc_time_change(hass, action, year=None, month=None, day=None,
 
             action(now)
 
-    hass.bus.listen(EVENT_TIME_CHANGED, pattern_time_change_listener)
+    return hass.bus.listen(EVENT_TIME_CHANGED, pattern_time_change_listener)
-    return pattern_time_change_listener
 
 
 # pylint: disable=too-many-arguments

homeassistant/helpers/script.py

@@ -7,7 +7,7 @@ from typing import Optional, Sequence
 import voluptuous as vol
 
 from homeassistant.core import HomeAssistant
-from homeassistant.const import EVENT_TIME_CHANGED, CONF_CONDITION
+from homeassistant.const import CONF_CONDITION
 from homeassistant.helpers import (
     service, condition, template, config_validation as cv)
 from homeassistant.helpers.event import track_point_in_utc_time
@@ -47,7 +47,7 @@ class Script():
         self.can_cancel = any(CONF_DELAY in action for action
                               in self.sequence)
         self._lock = threading.Lock()
-        self._delay_listener = None
+        self._unsub_delay_listener = None
 
     @property
     def is_running(self) -> bool:
@@ -72,7 +72,7 @@ class Script():
                     # Call ourselves in the future to continue work
                     def script_delay(now):
                         """Called after delay is done."""
-                        self._delay_listener = None
+                        self._unsub_delay_listener = None
                         self.run(variables)
 
                     delay = action[CONF_DELAY]
@@ -83,7 +83,7 @@ class Script():
                             cv.positive_timedelta)(
                                 template.render(self.hass, delay))
 
-                    self._delay_listener = track_point_in_utc_time(
+                    self._unsub_delay_listener = track_point_in_utc_time(
                         self.hass, script_delay,
                         date_util.utcnow() + delay)
                     self._cur = cur + 1
@@ -139,10 +139,9 @@ class Script():
 
     def _remove_listener(self):
         """Remove point in time listener, if any."""
-        if self._delay_listener:
+        if self._unsub_delay_listener:
-            self.hass.bus.remove_listener(EVENT_TIME_CHANGED,
+            self._unsub_delay_listener()
-                                          self._delay_listener)
+            self._unsub_delay_listener = None
-            self._delay_listener = None
 
     def _log(self, msg):
         """Logger helper."""

tests/components/mqtt/test_init.py

@@ -149,7 +149,7 @@ class TestMQTT(unittest.TestCase):
 
     def test_subscribe_topic(self):
         """Test the subscription of a topic."""
-        mqtt.subscribe(self.hass, 'test-topic', self.record_calls)
+        unsub = mqtt.subscribe(self.hass, 'test-topic', self.record_calls)
 
         fire_mqtt_message(self.hass, 'test-topic', 'test-payload')
 
@@ -158,6 +158,13 @@ class TestMQTT(unittest.TestCase):
         self.assertEqual('test-topic', self.calls[0][0])
         self.assertEqual('test-payload', self.calls[0][1])
 
+        unsub()
+
+        fire_mqtt_message(self.hass, 'test-topic', 'test-payload')
+
+        self.hass.pool.block_till_done()
+        self.assertEqual(1, len(self.calls))
+
     def test_subscribe_topic_not_match(self):
         """Test if subscribed topic is not a match."""
         mqtt.subscribe(self.hass, 'test-topic', self.record_calls)

tests/helpers/test_event.py

@@ -65,13 +65,21 @@ class TestEventHelpers(unittest.TestCase):
         self.hass.pool.block_till_done()
         self.assertEqual(2, len(runs))
 
+        unsub = track_point_in_time(
+            self.hass, lambda x: runs.append(1), birthday_paulus)
+        unsub()
+
+        self._send_time_changed(after_birthday)
+        self.hass.pool.block_till_done()
+        self.assertEqual(2, len(runs))
+
     def test_track_time_change(self):
         """Test tracking time change."""
         wildcard_runs = []
         specific_runs = []
 
-        track_time_change(self.hass, lambda x: wildcard_runs.append(1))
+        unsub = track_time_change(self.hass, lambda x: wildcard_runs.append(1))
-        track_utc_time_change(
+        unsub_utc = track_utc_time_change(
             self.hass, lambda x: specific_runs.append(1), second=[0, 30])
 
         self._send_time_changed(datetime(2014, 5, 24, 12, 0, 0))
@@ -89,6 +97,14 @@ class TestEventHelpers(unittest.TestCase):
         self.assertEqual(2, len(specific_runs))
         self.assertEqual(3, len(wildcard_runs))
 
+        unsub()
+        unsub_utc()
+
+        self._send_time_changed(datetime(2014, 5, 24, 12, 0, 30))
+        self.hass.pool.block_till_done()
+        self.assertEqual(2, len(specific_runs))
+        self.assertEqual(3, len(wildcard_runs))
+
     def test_track_state_change(self):
         """Test track_state_change."""
         # 2 lists to track how often our callbacks get called
@@ -186,11 +202,12 @@ class TestEventHelpers(unittest.TestCase):
 
         # Track sunrise
         runs = []
-        track_sunrise(self.hass, lambda: runs.append(1))
+        unsub = track_sunrise(self.hass, lambda: runs.append(1))
 
         offset_runs = []
         offset = timedelta(minutes=30)
-        track_sunrise(self.hass, lambda: offset_runs.append(1), offset)
+        unsub2 = track_sunrise(self.hass, lambda: offset_runs.append(1),
+                               offset)
 
         # run tests
         self._send_time_changed(next_rising - offset)
@@ -208,6 +225,14 @@ class TestEventHelpers(unittest.TestCase):
         self.assertEqual(2, len(runs))
         self.assertEqual(1, len(offset_runs))
 
+        unsub()
+        unsub2()
+
+        self._send_time_changed(next_rising + offset)
+        self.hass.pool.block_till_done()
+        self.assertEqual(2, len(runs))
+        self.assertEqual(1, len(offset_runs))
+
     def test_track_sunset(self):
         """Test track the sunset."""
         latitude = 32.87336
@@ -232,11 +257,11 @@ class TestEventHelpers(unittest.TestCase):
 
         # Track sunset
         runs = []
-        track_sunset(self.hass, lambda: runs.append(1))
+        unsub = track_sunset(self.hass, lambda: runs.append(1))
 
         offset_runs = []
         offset = timedelta(minutes=30)
-        track_sunset(self.hass, lambda: offset_runs.append(1), offset)
+        unsub2 = track_sunset(self.hass, lambda: offset_runs.append(1), offset)
 
         # Run tests
         self._send_time_changed(next_setting - offset)
@@ -254,6 +279,14 @@ class TestEventHelpers(unittest.TestCase):
         self.assertEqual(2, len(runs))
         self.assertEqual(1, len(offset_runs))
 
+        unsub()
+        unsub2()
+
+        self._send_time_changed(next_setting + offset)
+        self.hass.pool.block_till_done()
+        self.assertEqual(2, len(runs))
+        self.assertEqual(1, len(offset_runs))
+
     def _send_time_changed(self, now):
         """Send a time changed event."""
         self.hass.bus.fire(ha.EVENT_TIME_CHANGED, {ha.ATTR_NOW: now})
@@ -262,7 +295,7 @@ class TestEventHelpers(unittest.TestCase):
         """Test periodic tasks per minute."""
         specific_runs = []
 
-        track_utc_time_change(
+        unsub = track_utc_time_change(
             self.hass, lambda x: specific_runs.append(1), minute='/5')
 
         self._send_time_changed(datetime(2014, 5, 24, 12, 0, 0))
@@ -277,11 +310,17 @@ class TestEventHelpers(unittest.TestCase):
         self.hass.pool.block_till_done()
         self.assertEqual(2, len(specific_runs))
 
+        unsub()
+
+        self._send_time_changed(datetime(2014, 5, 24, 12, 5, 0))
+        self.hass.pool.block_till_done()
+        self.assertEqual(2, len(specific_runs))
+
     def test_periodic_task_hour(self):
         """Test periodic tasks per hour."""
         specific_runs = []
 
-        track_utc_time_change(
+        unsub = track_utc_time_change(
             self.hass, lambda x: specific_runs.append(1), hour='/2')
 
         self._send_time_changed(datetime(2014, 5, 24, 22, 0, 0))
@@ -304,11 +343,17 @@ class TestEventHelpers(unittest.TestCase):
         self.hass.pool.block_till_done()
         self.assertEqual(3, len(specific_runs))
 
+        unsub()
+
+        self._send_time_changed(datetime(2014, 5, 25, 2, 0, 0))
+        self.hass.pool.block_till_done()
+        self.assertEqual(3, len(specific_runs))
+
     def test_periodic_task_day(self):
         """Test periodic tasks per day."""
         specific_runs = []
 
-        track_utc_time_change(
+        unsub = track_utc_time_change(
             self.hass, lambda x: specific_runs.append(1), day='/2')
 
         self._send_time_changed(datetime(2014, 5, 2, 0, 0, 0))
@@ -323,11 +368,17 @@ class TestEventHelpers(unittest.TestCase):
         self.hass.pool.block_till_done()
         self.assertEqual(2, len(specific_runs))
 
+        unsub()
+
+        self._send_time_changed(datetime(2014, 5, 4, 0, 0, 0))
+        self.hass.pool.block_till_done()
+        self.assertEqual(2, len(specific_runs))
+
     def test_periodic_task_year(self):
         """Test periodic tasks per year."""
         specific_runs = []
 
-        track_utc_time_change(
+        unsub = track_utc_time_change(
             self.hass, lambda x: specific_runs.append(1), year='/2')
 
         self._send_time_changed(datetime(2014, 5, 2, 0, 0, 0))
@@ -342,6 +393,12 @@ class TestEventHelpers(unittest.TestCase):
         self.hass.pool.block_till_done()
         self.assertEqual(2, len(specific_runs))
 
+        unsub()
+
+        self._send_time_changed(datetime(2016, 5, 2, 0, 0, 0))
+        self.hass.pool.block_till_done()
+        self.assertEqual(2, len(specific_runs))
+
     def test_periodic_task_wrong_input(self):
         """Test periodic tasks with wrong input."""
         specific_runs = []

tests/test_core.py

@@ -175,6 +175,29 @@ class TestEventBus(unittest.TestCase):
         # Try deleting listener while category doesn't exist either
         self.bus.remove_listener('test', listener)
 
+    def test_unsubscribe_listener(self):
+        """Test unsubscribe listener from returned function."""
+        self.bus._pool.add_worker()
+        calls = []
+
+        def listener(event):
+            """Mock listener."""
+            calls.append(event)
+
+        unsub = self.bus.listen('test', listener)
+
+        self.bus.fire('test')
+        self.bus._pool.block_till_done()
+
+        assert len(calls) == 1
+
+        unsub()
+
+        self.bus.fire('event')
+        self.bus._pool.block_till_done()
+
+        assert len(calls) == 1
+
     def test_listen_once_event(self):
         """Test listen_once_event method."""
         runs = []