core/homeassistant/components/template/template_entity.py

367 lines
12 KiB
Python

"""TemplateEntity utility class."""
from __future__ import annotations
from collections.abc import Callable
import itertools
import logging
from typing import Any
import voluptuous as vol
from homeassistant.const import (
ATTR_ENTITY_ID,
CONF_ENTITY_PICTURE_TEMPLATE,
CONF_ICON,
CONF_ICON_TEMPLATE,
)
from homeassistant.core import EVENT_HOMEASSISTANT_START, CoreState, callback
from homeassistant.exceptions import TemplateError
import homeassistant.helpers.config_validation as cv
from homeassistant.helpers.entity import Entity
from homeassistant.helpers.event import (
Event,
TrackTemplate,
TrackTemplateResult,
async_track_template_result,
)
from homeassistant.helpers.template import Template, result_as_boolean
from .const import (
CONF_ATTRIBUTE_TEMPLATES,
CONF_ATTRIBUTES,
CONF_AVAILABILITY,
CONF_AVAILABILITY_TEMPLATE,
CONF_PICTURE,
)
_LOGGER = logging.getLogger(__name__)
TEMPLATE_ENTITY_COMMON_SCHEMA = vol.Schema(
{
vol.Optional(CONF_ATTRIBUTES): vol.Schema({cv.string: cv.template}),
vol.Optional(CONF_AVAILABILITY): cv.template,
vol.Optional(CONF_ICON): cv.template,
vol.Optional(CONF_PICTURE): cv.template,
}
)
TEMPLATE_ENTITY_AVAILABILITY_SCHEMA_LEGACY = vol.Schema(
{
vol.Optional(CONF_AVAILABILITY_TEMPLATE): cv.template,
}
)
TEMPLATE_ENTITY_COMMON_SCHEMA_LEGACY = vol.Schema(
{
vol.Optional(CONF_ENTITY_PICTURE_TEMPLATE): cv.template,
vol.Optional(CONF_ICON_TEMPLATE): cv.template,
}
).extend(TEMPLATE_ENTITY_AVAILABILITY_SCHEMA_LEGACY.schema)
LEGACY_FIELDS = {
CONF_ICON_TEMPLATE: CONF_ICON,
CONF_ENTITY_PICTURE_TEMPLATE: CONF_PICTURE,
CONF_AVAILABILITY_TEMPLATE: CONF_AVAILABILITY,
CONF_ATTRIBUTE_TEMPLATES: CONF_ATTRIBUTES,
}
def rewrite_common_legacy_to_modern_conf(
entity_cfg: dict[str, Any], extra_legacy_fields: dict[str, str] = None
) -> list[dict]:
"""Rewrite legacy config."""
entity_cfg = {**entity_cfg}
if extra_legacy_fields is None:
extra_legacy_fields = {}
for from_key, to_key in itertools.chain(
LEGACY_FIELDS.items(), extra_legacy_fields.items()
):
if from_key not in entity_cfg or to_key in entity_cfg:
continue
val = entity_cfg.pop(from_key)
if isinstance(val, str):
val = Template(val)
entity_cfg[to_key] = val
return entity_cfg
class _TemplateAttribute:
"""Attribute value linked to template result."""
def __init__(
self,
entity: Entity,
attribute: str,
template: Template,
validator: Callable[[Any], Any] = None,
on_update: Callable[[Any], None] | None = None,
none_on_template_error: bool | None = False,
) -> None:
"""Template attribute."""
self._entity = entity
self._attribute = attribute
self.template = template
self.validator = validator
self.on_update = on_update
self.async_update = None
self.none_on_template_error = none_on_template_error
@callback
def async_setup(self):
"""Config update path for the attribute."""
if self.on_update:
return
if not hasattr(self._entity, self._attribute):
raise AttributeError(f"Attribute '{self._attribute}' does not exist.")
self.on_update = self._default_update
@callback
def _default_update(self, result):
attr_result = None if isinstance(result, TemplateError) else result
setattr(self._entity, self._attribute, attr_result)
@callback
def handle_result(
self,
event: Event | None,
template: Template,
last_result: str | None | TemplateError,
result: str | TemplateError,
) -> None:
"""Handle a template result event callback."""
if isinstance(result, TemplateError):
_LOGGER.error(
"TemplateError('%s') "
"while processing template '%s' "
"for attribute '%s' in entity '%s'",
result,
self.template,
self._attribute,
self._entity.entity_id,
)
if self.none_on_template_error:
self._default_update(result)
else:
self.on_update(result)
return
if not self.validator:
self.on_update(result)
return
try:
validated = self.validator(result)
except vol.Invalid as ex:
_LOGGER.error(
"Error validating template result '%s' "
"from template '%s' "
"for attribute '%s' in entity %s "
"validation message '%s'",
result,
self.template,
self._attribute,
self._entity.entity_id,
ex.msg,
)
self.on_update(None)
return
self.on_update(validated)
return
class TemplateEntity(Entity):
"""Entity that uses templates to calculate attributes."""
_attr_available = True
_attr_entity_picture = None
_attr_icon = None
_attr_should_poll = False
def __init__(
self,
*,
availability_template=None,
icon_template=None,
entity_picture_template=None,
attribute_templates=None,
config=None,
):
"""Template Entity."""
self._template_attrs = {}
self._async_update = None
self._attr_extra_state_attributes = {}
self._self_ref_update_count = 0
if config is None:
self._attribute_templates = attribute_templates
self._availability_template = availability_template
self._icon_template = icon_template
self._entity_picture_template = entity_picture_template
else:
self._attribute_templates = config.get(CONF_ATTRIBUTES)
self._availability_template = config.get(CONF_AVAILABILITY)
self._icon_template = config.get(CONF_ICON)
self._entity_picture_template = config.get(CONF_PICTURE)
@callback
def _update_available(self, result):
if isinstance(result, TemplateError):
self._attr_available = True
return
self._attr_available = result_as_boolean(result)
@callback
def _update_state(self, result):
if self._availability_template:
return
self._attr_available = not isinstance(result, TemplateError)
@callback
def _add_attribute_template(self, attribute_key, attribute_template):
"""Create a template tracker for the attribute."""
def _update_attribute(result):
attr_result = None if isinstance(result, TemplateError) else result
self._attr_extra_state_attributes[attribute_key] = attr_result
self.add_template_attribute(
attribute_key, attribute_template, None, _update_attribute
)
def add_template_attribute(
self,
attribute: str,
template: Template,
validator: Callable[[Any], Any] = None,
on_update: Callable[[Any], None] | None = None,
none_on_template_error: bool = False,
) -> None:
"""
Call in the constructor to add a template linked to a attribute.
Parameters
----------
attribute
The name of the attribute to link to. This attribute must exist
unless a custom on_update method is supplied.
template
The template to calculate.
validator
Validator function to parse the result and ensure it's valid.
on_update
Called to store the template result rather than storing it
the supplied attribute. Passed the result of the validator, or None
if the template or validator resulted in an error.
"""
assert self.hass is not None, "hass cannot be None"
template.hass = self.hass
attribute = _TemplateAttribute(
self, attribute, template, validator, on_update, none_on_template_error
)
self._template_attrs.setdefault(template, [])
self._template_attrs[template].append(attribute)
@callback
def _handle_results(
self,
event: Event | None,
updates: list[TrackTemplateResult],
) -> None:
"""Call back the results to the attributes."""
if event:
self.async_set_context(event.context)
entity_id = event and event.data.get(ATTR_ENTITY_ID)
if entity_id and entity_id == self.entity_id:
self._self_ref_update_count += 1
else:
self._self_ref_update_count = 0
if self._self_ref_update_count > len(self._template_attrs):
for update in updates:
_LOGGER.warning(
"Template loop detected while processing event: %s, skipping template render for Template[%s]",
event,
update.template.template,
)
return
for update in updates:
for attr in self._template_attrs[update.template]:
attr.handle_result(
event, update.template, update.last_result, update.result
)
self.async_write_ha_state()
async def _async_template_startup(self, *_) -> None:
template_var_tups = []
has_availability_template = False
for template, attributes in self._template_attrs.items():
template_var_tup = TrackTemplate(template, None)
is_availability_template = False
for attribute in attributes:
# pylint: disable-next=protected-access
if attribute._attribute == "_attr_available":
has_availability_template = True
is_availability_template = True
attribute.async_setup()
# Insert the availability template first in the list
if is_availability_template:
template_var_tups.insert(0, template_var_tup)
else:
template_var_tups.append(template_var_tup)
result_info = async_track_template_result(
self.hass,
template_var_tups,
self._handle_results,
has_super_template=has_availability_template,
)
self.async_on_remove(result_info.async_remove)
self._async_update = result_info.async_refresh
result_info.async_refresh()
async def async_added_to_hass(self) -> None:
"""Run when entity about to be added to hass."""
if self._availability_template is not None:
self.add_template_attribute(
"_attr_available",
self._availability_template,
None,
self._update_available,
)
if self._attribute_templates is not None:
for key, value in self._attribute_templates.items():
self._add_attribute_template(key, value)
if self._icon_template is not None:
self.add_template_attribute(
"_attr_icon", self._icon_template, vol.Or(cv.whitespace, cv.icon)
)
if self._entity_picture_template is not None:
self.add_template_attribute(
"_attr_entity_picture", self._entity_picture_template
)
if self.hass.state == CoreState.running:
await self._async_template_startup()
return
self.hass.bus.async_listen_once(
EVENT_HOMEASSISTANT_START, self._async_template_startup
)
async def async_update(self) -> None:
"""Call for forced update."""
self._async_update()