Merge pull request #120 from balloob/chore-platform-dependencies

Allow platforms to specify dependencies.

homeassistant/bootstrap.py

@@ -28,7 +28,9 @@ from homeassistant.const import (
 
 _LOGGER = logging.getLogger(__name__)
 
-ATTR_COMPONENT = "component"
+ATTR_COMPONENT = 'component'
+
+PLATFORM_FORMAT = '{}.{}'
 
 
 def setup_component(hass, domain, config=None):
@@ -67,7 +69,7 @@ def _setup_component(hass, domain, config):
 
     if missing_deps:
         _LOGGER.error(
-            "Not initializing %s because not all dependencies loaded: %s",
+            'Not initializing %s because not all dependencies loaded: %s',
             domain, ", ".join(missing_deps))
 
         return False
@@ -87,14 +89,43 @@ def _setup_component(hass, domain, config):
             return True
 
         else:
-            _LOGGER.error("component %s failed to initialize", domain)
+            _LOGGER.error('component %s failed to initialize', domain)
 
     except Exception:  # pylint: disable=broad-except
-        _LOGGER.exception("Error during setup of component %s", domain)
+        _LOGGER.exception('Error during setup of component %s', domain)
 
     return False
 
 
+def prepare_setup_platform(hass, config, domain, platform_name):
+    """ Loads a platform and makes sure dependencies are setup. """
+    _ensure_loader_prepared(hass)
+
+    platform_path = PLATFORM_FORMAT.format(domain, platform_name)
+
+    platform = loader.get_component(platform_path)
+
+    # Not found
+    if platform is None:
+        _LOGGER.error('Unable to find platform %s', platform_path)
+        return None
+
+    # Already loaded or no dependencies
+    elif (platform_path in hass.config.components or
+          not hasattr(platform, 'DEPENDENCIES')):
+        return platform
+
+    # Load dependencies
+    for component in platform.DEPENDENCIES:
+        if not setup_component(hass, component, config):
+            _LOGGER.error(
+                'Unable to prepare setup for platform %s because dependency '
+                '%s could not be initialized', platform_path, component)
+            return None
+
+    return platform
+
+
 # pylint: disable=too-many-branches, too-many-statements
 def from_config_dict(config, hass=None):
     """
@@ -122,12 +153,12 @@ def from_config_dict(config, hass=None):
                   if ' ' not in key and key != homeassistant.DOMAIN)
 
     if not core_components.setup(hass, config):
-        _LOGGER.error("Home Assistant core failed to initialize. "
-                      "Further initialization aborted.")
+        _LOGGER.error('Home Assistant core failed to initialize. '
+                      'Further initialization aborted.')
 
         return hass
 
-    _LOGGER.info("Home Assistant core initialized")
+    _LOGGER.info('Home Assistant core initialized')
 
     # Setup the components
     for domain in loader.load_order_components(components):
@@ -158,7 +189,7 @@ def enable_logging(hass):
     logging.basicConfig(level=logging.INFO)
 
     # Log errors to a file if we have write access to file or config dir
-    err_log_path = hass.config.path("home-assistant.log")
+    err_log_path = hass.config.path('home-assistant.log')
     err_path_exists = os.path.isfile(err_log_path)
 
     # Check if we can write to the error log if it exists or that
@@ -177,7 +208,7 @@ def enable_logging(hass):
 
     else:
         _LOGGER.error(
-            "Unable to setup error log %s (access denied)", err_log_path)
+            'Unable to setup error log %s (access denied)', err_log_path)
 
 
 def process_ha_core_config(hass, config):
@@ -195,7 +226,7 @@ def process_ha_core_config(hass, config):
             hac.time_zone = time_zone
             date_util.set_default_time_zone(time_zone)
         else:
-            _LOGGER.error("Received invalid time zone %s", time_zone_str)
+            _LOGGER.error('Received invalid time zone %s', time_zone_str)
 
     for key, attr in ((CONF_LATITUDE, 'latitude'),
                       (CONF_LONGITUDE, 'longitude'),

homeassistant/helpers/entity_component.py

@@ -4,7 +4,7 @@ homeassistant.helpers.entity_component
 
 Provides helpers for components that manage entities.
 """
-from homeassistant.loader import get_component
+from homeassistant.bootstrap import prepare_setup_platform
 from homeassistant.helpers import (
     generate_entity_id, config_per_platform, extract_entity_ids)
 from homeassistant.components import group, discovery
@@ -45,7 +45,7 @@ class EntityComponent(object):
         for p_type, p_config in \
                 config_per_platform(config, self.domain, self.logger):
 
-            self._setup_platform(p_type, p_config)
+            self._setup_platform(config, p_type, p_config)
 
         if self.discovery_platforms:
             discovery.listen(self.hass, self.discovery_platforms.keys(),
@@ -115,18 +115,20 @@ class EntityComponent(object):
             self._update_entity_states,
             second=range(0, 60, self.scan_interval))
 
-    def _setup_platform(self, platform_type, config, discovery_info=None):
+    def _setup_platform(self, config, platform_type, platform_config,
+                        discovery_info=None):
         """ Tries to setup a platform for this component. """
-        platform_name = '{}.{}'.format(self.domain, platform_type)
-        platform = get_component(platform_name)
+        platform = prepare_setup_platform(
+            self.hass, config, self.domain, platform_type)
 
         if platform is None:
-            self.logger.error('Unable to find platform %s', platform_type)
             return
 
+        platform_name = '{}.{}'.format(self.domain, platform_type)
+
         try:
             platform.setup_platform(
-                self.hass, config, self.add_entities, discovery_info)
+                self.hass, platform_config, self.add_entities, discovery_info)
 
             self.hass.config.components.append(platform_name)
 
@@ -135,15 +137,16 @@ class EntityComponent(object):
             # Support old deprecated method for now - 3/1/2015
             if hasattr(platform, 'get_devices'):
                 self.logger.warning(
-                    "Please upgrade %s to return new entities using "
-                    "setup_platform. See %s/demo.py for an example.",
+                    'Please upgrade %s to return new entities using '
+                    'setup_platform. See %s/demo.py for an example.',
                     platform_name, self.domain)
-                self.add_entities(platform.get_devices(self.hass, config))
+                self.add_entities(
+                    platform.get_devices(self.hass, platform_config))
 
             else:
                 self.logger.exception(
-                    "Error while setting up platform %s", platform_type)
+                    'Error while setting up platform %s', platform_type)
 
         except Exception:  # pylint: disable=broad-except
             self.logger.exception(
-                "Error while setting up platform %s", platform_type)
+                'Error while setting up platform %s', platform_type)