mirror of https://github.com/home-assistant/core
108 lines
2.8 KiB
Python
108 lines
2.8 KiB
Python
|
"""
|
||
|
|
homeassistant.loader
|
||
|
|
~~~~~~~~~~~~~~~~~~~~
|
||
|
|
|
||
|
|
Provides methods for loading Home Assistant components.
|
||
|
|
"""
|
||
|
|
import sys
|
||
|
|
import pkgutil
|
||
|
|
import importlib
|
||
|
|
import logging
|
||
|
|
|
||
|
|
# List of available components
|
||
|
|
AVAILABLE_COMPONENTS = []
|
||
|
|
|
||
|
|
# Dict of loaded components mapped name => module
|
||
|
|
_COMPONENT_CACHE = {}
|
||
|
|
|
||
|
|
_LOGGER = logging.getLogger(__name__)
|
||
|
|
|
||
|
|
|
||
|
|
def prepare(hass):
|
||
|
|
""" Prepares the loading of components. """
|
||
|
|
# Ensure we can load custom components from the config dir
|
||
|
|
sys.path.append(hass.config_dir)
|
||
|
|
|
||
|
|
# pylint: disable=import-error
|
||
|
|
import custom_components
|
||
|
|
import homeassistant.components as components
|
||
|
|
|
||
|
|
AVAILABLE_COMPONENTS.clear()
|
||
|
|
|
||
|
|
AVAILABLE_COMPONENTS.extend(
|
||
|
|
item[1] for item in
|
||
|
|
pkgutil.iter_modules(components.__path__, 'homeassistant.components.'))
|
||
|
|
|
||
|
|
AVAILABLE_COMPONENTS.extend(
|
||
|
|
item[1] for item in
|
||
|
|
pkgutil.iter_modules(custom_components.__path__, 'custom_components.'))
|
||
|
|
|
||
|
|
|
||
|
|
def get_component(comp_name):
|
||
|
|
""" Tries to load specified component.
|
||
|
|
Looks in config dir first, then built-in components.
|
||
|
|
Only returns it if also found to be valid. """
|
||
|
|
|
||
|
|
if comp_name in _COMPONENT_CACHE:
|
||
|
|
return _COMPONENT_CACHE[comp_name]
|
||
|
|
|
||
|
|
# First check config dir, then built-in
|
||
|
|
potential_paths = [path for path in
|
||
|
|
['custom_components.{}'.format(comp_name),
|
||
|
|
'homeassistant.components.{}'.format(comp_name)]
|
||
|
|
if path in AVAILABLE_COMPONENTS]
|
||
|
|
|
||
|
|
if not potential_paths:
|
||
|
|
_LOGGER.error("Failed to find component {}".format(comp_name))
|
||
|
|
|
||
|
|
return None
|
||
|
|
|
||
|
|
for path in potential_paths:
|
||
|
|
comp = _get_component(path)
|
||
|
|
|
||
|
|
if comp is not None:
|
||
|
|
_LOGGER.info("Loaded component {} from {}".format(
|
||
|
|
comp_name, path))
|
||
|
|
|
||
|
|
_COMPONENT_CACHE[comp_name] = comp
|
||
|
|
|
||
|
|
return comp
|
||
|
|
|
||
|
|
# We did find components but were unable to load them
|
||
|
|
_LOGGER.error("Unable to load component {}".format(comp_name))
|
||
|
|
|
||
|
|
return None
|
||
|
|
|
||
|
|
|
||
|
|
def _get_component(module):
|
||
|
|
""" Tries to load specified component.
|
||
|
|
Only returns it if also found to be valid."""
|
||
|
|
try:
|
||
|
|
comp = importlib.import_module(module)
|
||
|
|
|
||
|
|
except ImportError:
|
||
|
|
_LOGGER.exception("Error loading {}".format(module))
|
||
|
|
|
||
|
|
return None
|
||
|
|
|
||
|
|
# Validation if component has required methods and attributes
|
||
|
|
errors = []
|
||
|
|
|
||
|
|
if not hasattr(comp, 'DOMAIN'):
|
||
|
|
errors.append("missing DOMAIN attribute")
|
||
|
|
|
||
|
|
if not hasattr(comp, 'DEPENDENCIES'):
|
||
|
|
errors.append("missing DEPENDENCIES attribute")
|
||
|
|
|
||
|
|
if not hasattr(comp, 'setup'):
|
||
|
|
errors.append("missing setup method")
|
||
|
|
|
||
|
|
if errors:
|
||
|
|
_LOGGER.error("Found invalid component {}: {}".format(
|
||
|
|
module, ", ".join(errors)))
|
||
|
|
|
||
|
|
return None
|
||
|
|
|
||
|
|
else:
|
||
|
|
return comp
|