core/homeassistant/components/demo/sensor.py

"""Demo platform that has a couple of fake sensors."""
from homeassistant.const import (
    ATTR_BATTERY_LEVEL,
    TEMP_CELSIUS,
    DEVICE_CLASS_HUMIDITY,
    DEVICE_CLASS_TEMPERATURE,
)
from homeassistant.helpers.entity import Entity


def setup_platform(hass, config, add_entities, discovery_info=None):
    """Set up the Demo sensors."""
    add_entities(
        [
            DemoSensor(
                "Outside Temperature", 15.6, DEVICE_CLASS_TEMPERATURE, TEMP_CELSIUS, 12
            ),
            DemoSensor("Outside Humidity", 54, DEVICE_CLASS_HUMIDITY, "%", None),
        ]
    )


class DemoSensor(Entity):
    """Representation of a Demo sensor."""

    def __init__(self, name, state, device_class, unit_of_measurement, battery):
        """Initialize the sensor."""
        self._name = name
        self._state = state
        self._device_class = device_class
        self._unit_of_measurement = unit_of_measurement
        self._battery = battery

    @property
    def should_poll(self):
        """No polling needed for a demo sensor."""
        return False

    @property
    def device_class(self):
        """Return the device class of the sensor."""
        return self._device_class

    @property
    def name(self):
        """Return the name of the sensor."""
        return self._name

    @property
    def state(self):
        """Return the state of the sensor."""
        return self._state

    @property
    def unit_of_measurement(self):
        """Return the unit this state is expressed in."""
        return self._unit_of_measurement

    @property
    def device_state_attributes(self):
        """Return the state attributes."""
        if self._battery:
            return {ATTR_BATTERY_LEVEL: self._battery}