Minor cleanup - Define 'CONF_ICON_TEMPLATE' constant centrally (#7910)

* Add 'icon_template' to switch templates (similar to sensor template)

* Add test for template switch 'icon_template'

* Define 'CONF_ICON_TEMPLATE' constant centrally

* Missed a redundant definition

homeassistant/components/sensor/template.py

@@ -13,7 +13,8 @@ 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, EVENT_HOMEASSISTANT_START)
+    CONF_ICON_TEMPLATE, 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
@@ -22,8 +23,6 @@ from homeassistant.helpers.restore_state import async_get_last_state
 
 _LOGGER = logging.getLogger(__name__)
 
-CONF_ICON_TEMPLATE = 'icon_template'
-
 SENSOR_SCHEMA = vol.Schema({
     vol.Required(CONF_VALUE_TEMPLATE): cv.template,
     vol.Optional(CONF_ICON_TEMPLATE): cv.template,

homeassistant/components/switch/template.py

@@ -13,8 +13,8 @@ from homeassistant.core import callback
 from homeassistant.components.switch import (
     ENTITY_ID_FORMAT, SwitchDevice, PLATFORM_SCHEMA)
 from homeassistant.const import (
-    ATTR_FRIENDLY_NAME, CONF_VALUE_TEMPLATE, STATE_OFF, STATE_ON,
-    ATTR_ENTITY_ID, CONF_SWITCHES, EVENT_HOMEASSISTANT_START)
+    ATTR_FRIENDLY_NAME, CONF_VALUE_TEMPLATE, CONF_ICON_TEMPLATE, STATE_OFF,
+    STATE_ON, ATTR_ENTITY_ID, CONF_SWITCHES, EVENT_HOMEASSISTANT_START)
 from homeassistant.exceptions import TemplateError
 import homeassistant.helpers.config_validation as cv
 from homeassistant.helpers.entity import async_generate_entity_id
@@ -25,8 +25,6 @@ from homeassistant.helpers.script import Script
 _LOGGER = logging.getLogger(__name__)
 _VALID_STATES = [STATE_ON, STATE_OFF, 'true', 'false']
 
-CONF_ICON_TEMPLATE = 'icon_template'
-
 ON_ACTION = 'turn_on'
 OFF_ACTION = 'turn_off'
 

homeassistant/const.py

@@ -105,6 +105,7 @@ CONF_HEADERS = 'headers'
 CONF_HOST = 'host'
 CONF_HOSTS = 'hosts'
 CONF_ICON = 'icon'
+CONF_ICON_TEMPLATE = 'icon_template'
 CONF_INCLUDE = 'include'
 CONF_ID = 'id'
 CONF_LATITUDE = 'latitude'