core/homeassistant/helpers/template.py

309 lines
9.6 KiB
Python

"""Template helper methods for rendering strings with HA data."""
# pylint: disable=too-few-public-methods
import json
import logging
import jinja2
from jinja2.sandbox import ImmutableSandboxedEnvironment
from homeassistant.const import STATE_UNKNOWN, ATTR_LATITUDE, ATTR_LONGITUDE
from homeassistant.core import State
from homeassistant.exceptions import TemplateError
from homeassistant.helpers import location as loc_helper
from homeassistant.loader import get_component
from homeassistant.util import convert, dt as dt_util, location as loc_util
_LOGGER = logging.getLogger(__name__)
_SENTINEL = object()
DATE_STR_FORMAT = "%Y-%m-%d %H:%M:%S"
def render_with_possible_json_value(hass, template, value,
error_value=_SENTINEL):
"""Render template with value exposed.
If valid JSON will expose value_json too.
"""
variables = {
'value': value
}
try:
variables['value_json'] = json.loads(value)
except ValueError:
pass
try:
return render(hass, template, variables)
except TemplateError as ex:
_LOGGER.error('Error parsing value: %s', ex)
return value if error_value is _SENTINEL else error_value
def render(hass, template, variables=None, **kwargs):
"""Render given template."""
if variables is not None:
kwargs.update(variables)
location_methods = LocationMethods(hass)
utcnow = dt_util.utcnow()
try:
return ENV.from_string(template, {
'closest': location_methods.closest,
'distance': location_methods.distance,
'float': forgiving_float,
'is_state': hass.states.is_state,
'is_state_attr': hass.states.is_state_attr,
'now': dt_util.as_local(utcnow),
'states': AllStates(hass),
'utcnow': utcnow,
'as_timestamp': dt_util.as_timestamp,
'relative_time': dt_util.get_age
}).render(kwargs).strip()
except jinja2.TemplateError as err:
raise TemplateError(err)
class AllStates(object):
"""Class to expose all HA states as attributes."""
def __init__(self, hass):
"""Initialize all states."""
self._hass = hass
def __getattr__(self, name):
"""Return the domain state."""
return DomainStates(self._hass, name)
def __iter__(self):
"""Return all states."""
return iter(sorted(self._hass.states.all(),
key=lambda state: state.entity_id))
def __call__(self, entity_id):
"""Return the states."""
state = self._hass.states.get(entity_id)
return STATE_UNKNOWN if state is None else state.state
class DomainStates(object):
"""Class to expose a specific HA domain as attributes."""
def __init__(self, hass, domain):
"""Initialize the domain states."""
self._hass = hass
self._domain = domain
def __getattr__(self, name):
"""Return the states."""
return self._hass.states.get('{}.{}'.format(self._domain, name))
def __iter__(self):
"""Return the iteration over all the states."""
return iter(sorted(
(state for state in self._hass.states.all()
if state.domain == self._domain),
key=lambda state: state.entity_id))
class LocationMethods(object):
"""Class to expose distance helpers to templates."""
def __init__(self, hass):
"""Initialize the distance helpers."""
self._hass = hass
def closest(self, *args):
"""Find closest entity.
Closest to home:
closest(states)
closest(states.device_tracker)
closest('group.children')
closest(states.group.children)
Closest to a point:
closest(23.456, 23.456, 'group.children')
closest('zone.school', 'group.children')
closest(states.zone.school, 'group.children')
"""
if len(args) == 1:
latitude = self._hass.config.latitude
longitude = self._hass.config.longitude
entities = args[0]
elif len(args) == 2:
point_state = self._resolve_state(args[0])
if point_state is None:
_LOGGER.warning('Closest:Unable to find state %s', args[0])
return None
elif not loc_helper.has_location(point_state):
_LOGGER.warning(
'Closest:State does not contain valid location: %s',
point_state)
return None
latitude = point_state.attributes.get(ATTR_LATITUDE)
longitude = point_state.attributes.get(ATTR_LONGITUDE)
entities = args[1]
else:
latitude = convert(args[0], float)
longitude = convert(args[1], float)
if latitude is None or longitude is None:
_LOGGER.warning(
'Closest:Received invalid coordinates: %s, %s',
args[0], args[1])
return None
entities = args[2]
if isinstance(entities, (AllStates, DomainStates)):
states = list(entities)
else:
if isinstance(entities, State):
gr_entity_id = entities.entity_id
else:
gr_entity_id = str(entities)
group = get_component('group')
states = [self._hass.states.get(entity_id) for entity_id
in group.expand_entity_ids(self._hass, [gr_entity_id])]
return loc_helper.closest(latitude, longitude, states)
def distance(self, *args):
"""Calculate distance.
Will calculate distance from home to a point or between points.
Points can be passed in using state objects or lat/lng coordinates.
"""
locations = []
to_process = list(args)
while to_process:
value = to_process.pop(0)
if isinstance(value, State):
latitude = value.attributes.get(ATTR_LATITUDE)
longitude = value.attributes.get(ATTR_LONGITUDE)
if latitude is None or longitude is None:
_LOGGER.warning(
'Distance:State does not contains a location: %s',
value)
return None
else:
# We expect this and next value to be lat&lng
if not to_process:
_LOGGER.warning(
'Distance:Expected latitude and longitude, got %s',
value)
return None
value_2 = to_process.pop(0)
latitude = convert(value, float)
longitude = convert(value_2, float)
if latitude is None or longitude is None:
_LOGGER.warning('Distance:Unable to process latitude and '
'longitude: %s, %s', value, value_2)
return None
locations.append((latitude, longitude))
if len(locations) == 1:
return self._hass.config.distance(*locations[0])
return self._hass.config.units.length(
loc_util.distance(*locations[0] + locations[1]), 'm')
def _resolve_state(self, entity_id_or_state):
"""Return state or entity_id if given."""
if isinstance(entity_id_or_state, State):
return entity_id_or_state
elif isinstance(entity_id_or_state, str):
return self._hass.states.get(entity_id_or_state)
return None
def forgiving_round(value, precision=0):
"""Rounding filter that accepts strings."""
try:
value = round(float(value), precision)
return int(value) if precision == 0 else value
except (ValueError, TypeError):
# If value can't be converted to float
return value
def multiply(value, amount):
"""Filter to convert value to float and multiply it."""
try:
return float(value) * amount
except (ValueError, TypeError):
# If value can't be converted to float
return value
def timestamp_custom(value, date_format=DATE_STR_FORMAT, local=True):
"""Filter to convert given timestamp to format."""
try:
date = dt_util.utc_from_timestamp(value)
if local:
date = dt_util.as_local(date)
return date.strftime(date_format)
except (ValueError, TypeError):
# If timestamp can't be converted
return value
def timestamp_local(value):
"""Filter to convert given timestamp to local date/time."""
try:
return dt_util.as_local(
dt_util.utc_from_timestamp(value)).strftime(DATE_STR_FORMAT)
except (ValueError, TypeError):
# If timestamp can't be converted
return value
def timestamp_utc(value):
"""Filter to convert given timestamp to UTC date/time."""
try:
return dt_util.utc_from_timestamp(value).strftime(DATE_STR_FORMAT)
except (ValueError, TypeError):
# If timestamp can't be converted
return value
def forgiving_float(value):
"""Try to convert value to a float."""
try:
return float(value)
except (ValueError, TypeError):
return value
class TemplateEnvironment(ImmutableSandboxedEnvironment):
"""The Home Assistant template environment."""
def is_safe_callable(self, obj):
"""Test if callback is safe."""
return isinstance(obj, AllStates) or super().is_safe_callable(obj)
ENV = TemplateEnvironment()
ENV.filters['round'] = forgiving_round
ENV.filters['multiply'] = multiply
ENV.filters['timestamp_custom'] = timestamp_custom
ENV.filters['timestamp_local'] = timestamp_local
ENV.filters['timestamp_utc'] = timestamp_utc