Add template support to rest sensor

homeassistant/components/sensor/rest.py

@@ -7,12 +7,12 @@ For more details about this platform, please refer to the documentation at
 https://home-assistant.io/components/sensor.rest/
 """
 from datetime import timedelta
-from json import loads
 import logging
-
 import requests
+import jinja2.exceptions
 
-from homeassistant.util import Throttle
+from homeassistant.const import CONF_VALUE_TEMPLATE
+from homeassistant.util import template, Throttle
 from homeassistant.helpers.entity import Entity
 
 _LOGGER = logging.getLogger(__name__)
@@ -59,57 +59,43 @@ def setup_platform(hass, config, add_devices, discovery_info=None):
                       'Please check the URL in the configuration file.')
         return False
 
-    try:
-        data = loads(response.text)
-    except ValueError:
-        _LOGGER.error('No valid JSON in the response in: %s', data)
-        return False
-
-    try:
-        RestSensor.extract_value(data, config.get('variable'))
-    except KeyError:
-        _LOGGER.error('Variable "%s" not found in response: "%s"',
-                      config.get('variable'), data)
-        return False
+    value_template = config.get(CONF_VALUE_TEMPLATE)
+    data = response.text
+    if value_template is not None:
+        try:
+            template.render_with_possible_json_value(hass,
+                                                     value_template,
+                                                     data)
+        except jinja2.exceptions.UndefinedError:
+            _LOGGER.error('Template "%s" not found in response: "%s"',
+                          value_template, data)
+            return False
 
     if use_get:
         rest = RestDataGet(resource, verify_ssl)
     elif use_post:
         rest = RestDataPost(resource, payload, verify_ssl)
 
-    add_devices([RestSensor(rest,
+    add_devices([RestSensor(hass,
+                            rest,
                             config.get('name', DEFAULT_NAME),
-                            config.get('variable'),
                             config.get('unit_of_measurement'),
-                            config.get('correction_factor', None),
-                            config.get('decimal_places', None))])
+                            config.get(CONF_VALUE_TEMPLATE))])
 
 
 # pylint: disable=too-many-arguments
 class RestSensor(Entity):
     """ Implements a REST sensor. """
 
-    def __init__(self, rest, name, variable, unit_of_measurement, corr_factor,
-                 decimal_places):
+    def __init__(self, hass, rest, name, unit_of_measurement, value_template):
+        self._hass = hass
         self.rest = rest
         self._name = name
-        self._variable = variable
         self._state = 'n/a'
         self._unit_of_measurement = unit_of_measurement
-        self._corr_factor = corr_factor
-        self._decimal_places = decimal_places
+        self._value_template = value_template
         self.update()
 
-    @classmethod
-    def extract_value(cls, data, variable):
-        """ Extracts the value using a key name or a path. """
-        if isinstance(variable, list):
-            for variable_item in variable:
-                data = data[variable_item]
-            return data
-        else:
-            return data[variable]
-
     @property
     def name(self):
         """ The name of the sensor. """
@@ -133,18 +119,10 @@ class RestSensor(Entity):
         if 'error' in value:
             self._state = value['error']
         else:
-            try:
-                if value is not None:
-                    value = RestSensor.extract_value(value, self._variable)
-                    if self._corr_factor is not None:
-                        value = float(value) * float(self._corr_factor)
-                    if self._decimal_places is not None:
-                        value = round(value, self._decimal_places)
-                    if self._decimal_places == 0:
-                        value = int(value)
-                    self._state = value
-            except ValueError:
-                self._state = RestSensor.extract_value(value, self._variable)
+            if self._value_template is not None:
+                value = template.render_with_possible_json_value(
+                    self._hass, self._value_template, value)
+            self._state = value
 
 
 # pylint: disable=too-few-public-methods
@@ -164,7 +142,7 @@ class RestDataGet(object):
                                     verify=self._verify_ssl)
             if 'error' in self.data:
                 del self.data['error']
-            self.data = response.json()
+            self.data = response.text
         except requests.exceptions.ConnectionError:
             _LOGGER.error("No route to resource/endpoint.")
             self.data['error'] = 'N/A'
@@ -188,7 +166,7 @@ class RestDataPost(object):
                                      timeout=10, verify=self._verify_ssl)
             if 'error' in self.data:
                 del self.data['error']
-            self.data = response.json()
+            self.data = response.text
         except requests.exceptions.ConnectionError:
             _LOGGER.error("No route to resource/endpoint.")
             self.data['error'] = 'N/A'