core/homeassistant/components/sensor/rest.py

111 lines
3.3 KiB
Python

"""
Support for REST API sensors..
For more details about this platform, please refer to the documentation at
https://home-assistant.io/components/sensor.rest/
"""
import logging
from datetime import timedelta
import requests
from homeassistant.const import CONF_VALUE_TEMPLATE, STATE_UNKNOWN
from homeassistant.helpers.entity import Entity
from homeassistant.helpers import template
from homeassistant.util import Throttle
_LOGGER = logging.getLogger(__name__)
DEFAULT_NAME = 'REST Sensor'
DEFAULT_METHOD = 'GET'
# Return cached results if last scan was less then this time ago
MIN_TIME_BETWEEN_UPDATES = timedelta(seconds=60)
# pylint: disable=unused-variable
def setup_platform(hass, config, add_devices, discovery_info=None):
"""Setup the REST sensor."""
resource = config.get('resource', None)
method = config.get('method', DEFAULT_METHOD)
payload = config.get('payload', None)
verify_ssl = config.get('verify_ssl', True)
rest = RestData(method, resource, payload, verify_ssl)
rest.update()
if rest.data is None:
_LOGGER.error('Unable to fetch Rest data')
return False
add_devices([RestSensor(
hass, rest, config.get('name', DEFAULT_NAME),
config.get('unit_of_measurement'), config.get(CONF_VALUE_TEMPLATE))])
# pylint: disable=too-many-arguments
class RestSensor(Entity):
"""Implementation of a REST sensor."""
def __init__(self, hass, rest, name, unit_of_measurement, value_template):
"""Initialize the sensor."""
self._hass = hass
self.rest = rest
self._name = name
self._state = STATE_UNKNOWN
self._unit_of_measurement = unit_of_measurement
self._value_template = value_template
self.update()
@property
def name(self):
"""Return the name of the sensor."""
return self._name
@property
def unit_of_measurement(self):
"""Return the unit the value is expressed in."""
return self._unit_of_measurement
@property
def state(self):
"""Return the state of the device."""
return self._state
def update(self):
"""Get the latest data from REST API and update the state."""
self.rest.update()
value = self.rest.data
if value is None:
value = STATE_UNKNOWN
elif self._value_template is not None:
value = template.render_with_possible_json_value(
self._hass, self._value_template, value, STATE_UNKNOWN)
self._state = value
# pylint: disable=too-few-public-methods
class RestData(object):
"""Class for handling the data retrieval."""
def __init__(self, method, resource, data, verify_ssl):
"""Initialize the data object."""
self._request = requests.Request(method, resource, data=data).prepare()
self._verify_ssl = verify_ssl
self.data = None
@Throttle(MIN_TIME_BETWEEN_UPDATES)
def update(self):
"""Get the latest data from REST service with GET method."""
try:
with requests.Session() as sess:
response = sess.send(self._request, timeout=10,
verify=self._verify_ssl)
self.data = response.text
except requests.exceptions.RequestException:
_LOGGER.error("Error fetching data: %s", self._request)
self.data = None