Template sensor change flow / add restore (#6336)

homeassistant/components/sensor/template.py

@@ -13,11 +13,12 @@ from homeassistant.core import callback
 from homeassistant.components.sensor import ENTITY_ID_FORMAT, PLATFORM_SCHEMA
 from homeassistant.const import (
     ATTR_FRIENDLY_NAME, ATTR_UNIT_OF_MEASUREMENT, CONF_VALUE_TEMPLATE,
-    ATTR_ENTITY_ID, CONF_SENSORS)
+    ATTR_ENTITY_ID, CONF_SENSORS, EVENT_HOMEASSISTANT_START)
 from homeassistant.exceptions import TemplateError
+import homeassistant.helpers.config_validation as cv
 from homeassistant.helpers.entity import Entity, async_generate_entity_id
 from homeassistant.helpers.event import async_track_state_change
-import homeassistant.helpers.config_validation as cv
+from homeassistant.helpers.restore_state import async_get_last_state
 
 _LOGGER = logging.getLogger(__name__)
 
@@ -69,7 +70,7 @@ def async_setup_platform(hass, config, async_add_devices, discovery_info=None):
         _LOGGER.error("No sensors added")
         return False
 
-    async_add_devices(sensors, True)
+    async_add_devices(sensors)
     return True
 
 
@@ -88,14 +89,30 @@ class SensorTemplate(Entity):
         self._state = None
         self._icon_template = icon_template
         self._icon = None
+        self._entities = entity_ids
+
+    @asyncio.coroutine
+    def async_added_to_hass(self):
+        """Register callbacks."""
+        state = yield from async_get_last_state(self.hass, self.entity_id)
+        if state:
+            self._state = state.state
 
         @callback
         def template_sensor_state_listener(entity, old_state, new_state):
             """Called when the target device changes state."""
-            hass.async_add_job(self.async_update_ha_state, True)
+            self.hass.async_add_job(self.async_update_ha_state(True))
 
-        async_track_state_change(
-            hass, entity_ids, template_sensor_state_listener)
+        @callback
+        def template_sensor_startup(event):
+            """Update template on startup."""
+            async_track_state_change(
+                self.hass, self._entities, template_sensor_state_listener)
+
+            self.hass.async_add_job(self.async_update_ha_state(True))
+
+        self.hass.bus.async_listen_once(
+            EVENT_HOMEASSISTANT_START, template_sensor_startup)
 
     @property
     def name(self):

tests/components/sensor/test_template.py

@@ -1,7 +1,12 @@
 """The test for the Template sensor platform."""
-from homeassistant.bootstrap import setup_component
+import asyncio
 
-from tests.common import get_test_home_assistant, assert_setup_component
+from homeassistant.core import CoreState, State
+from homeassistant.bootstrap import setup_component, async_setup_component
+from homeassistant.helpers.restore_state import DATA_RESTORE_CACHE
+
+from tests.common import (
+    get_test_home_assistant, assert_setup_component, mock_component)
 
 
 class TestTemplateSensor:
@@ -33,6 +38,8 @@ class TestTemplateSensor:
                 }
             })
 
+        self.hass.start()
+
         state = self.hass.states.get('sensor.test_template_sensor')
         assert state.state == 'It .'
 
@@ -60,6 +67,8 @@ class TestTemplateSensor:
                 }
             })
 
+        self.hass.start()
+
         state = self.hass.states.get('sensor.test_template_sensor')
         assert 'icon' not in state.attributes
 
@@ -82,6 +91,8 @@ class TestTemplateSensor:
                     }
                 }
             })
+
+        self.hass.start()
         assert self.hass.states.all() == []
 
     def test_template_attribute_missing(self):
@@ -99,6 +110,8 @@ class TestTemplateSensor:
                 }
             })
 
+        self.hass.start()
+
         state = self.hass.states.get('sensor.test_template_sensor')
         assert state.state == 'unknown'
 
@@ -116,6 +129,8 @@ class TestTemplateSensor:
                     }
                 }
             })
+
+        self.hass.start()
         assert self.hass.states.all() == []
 
     def test_invalid_sensor_does_not_create(self):
@@ -129,6 +144,8 @@ class TestTemplateSensor:
                     }
                 }
             })
+
+        self.hass.start()
         assert self.hass.states.all() == []
 
     def test_no_sensors_does_not_create(self):
@@ -139,6 +156,8 @@ class TestTemplateSensor:
                     'platform': 'template'
                 }
             })
+
+        self.hass.start()
         assert self.hass.states.all() == []
 
     def test_missing_template_does_not_create(self):
@@ -155,4 +174,39 @@ class TestTemplateSensor:
                     }
                 }
             })
+
+        self.hass.start()
         assert self.hass.states.all() == []
+
+
+@asyncio.coroutine
+def test_restore_state(hass):
+    """Ensure states are restored on startup."""
+    hass.data[DATA_RESTORE_CACHE] = {
+        'sensor.test_template_sensor':
+            State('sensor.test_template_sensor', 'It Test.'),
+    }
+
+    hass.state = CoreState.starting
+    mock_component(hass, 'recorder')
+
+    yield from async_setup_component(hass, 'sensor', {
+        'sensor': {
+            'platform': 'template',
+            'sensors': {
+                'test_template_sensor': {
+                    'value_template':
+                        "It {{ states.sensor.test_state.state }}."
+                }
+            }
+        }
+    })
+
+    state = hass.states.get('sensor.test_template_sensor')
+    assert state.state == 'It Test.'
+
+    yield from hass.async_start()
+    yield from hass.async_block_till_done()
+
+    state = hass.states.get('sensor.test_template_sensor')
+    assert state.state == 'It .'