platypush/platypush/context/__init__.py
2017-12-27 10:19:35 +01:00

93 lines
2.7 KiB
Python

import functools
import importlib
import logging
from ..config import Config
# Map: backend_name -> backend_instance
backends = {}
# Map: plugin_name -> plugin_instance
plugins = {}
def register_backends(bus=None, global_scope=False, **kwargs):
""" Initialize the backend objects based on the configuration and returns
a name -> backend_instance map.
Params:
bus -- If specific (it usually should), the messages processed by the
backends will be posted on this bus.
kwargs -- Any additional key-value parameters required to initialize the backends
"""
if global_scope:
global backends
else:
backends = {}
for (name, cfg) in Config.get_backends().items():
module = importlib.import_module('platypush.backend.' + name)
# e.g. backend.pushbullet main class: PushbulletBackend
cls_name = functools.reduce(
lambda a,b: a.title() + b.title(),
(module.__name__.title().split('.')[2:])
) + 'Backend'
try:
b = getattr(module, cls_name)(bus=bus, **cfg, **kwargs)
backends[name] = b
except AttributeError as e:
logging.warning('No such class in {}: {}'.format(
module.__name__, cls_name))
raise RuntimeError(e)
return backends
def get_backend(name):
""" Returns the backend instance identified by name if it exists """
global backends
return backends[name]
def get_plugin(plugin_name, reload=False):
""" Registers a plugin instance by name if not registered already, or
returns the registered plugin instance"""
global plugins
if plugin_name in plugins and not reload:
return plugins[plugin_name]
try:
plugin = importlib.import_module('platypush.plugins.' + plugin_name)
except ModuleNotFoundError as e:
logging.warning('No such plugin: {}'.format(plugin_name))
raise RuntimeError(e)
# e.g. plugins.music.mpd main class: MusicMpdPlugin
cls_name = functools.reduce(
lambda a,b: a.title() + b.title(),
(plugin_name.title().split('.'))
) + 'Plugin'
plugin_conf = Config.get_plugins()[plugin_name] \
if plugin_name in Config.get_plugins() else {}
try:
plugin_class = getattr(plugin, cls_name)
plugin = plugin_class(**plugin_conf)
plugins[plugin_name] = plugin
except AttributeError as e:
logging.warning('No such class in {}: {}'.format(plugin_name, cls_name))
raise RuntimeError(e)
plugins[plugin_name] = plugin
return plugin
def register_plugin(name, plugin, **kwargs):
""" Registers a plugin instance by name """
global plugins
# vim:sw=4:ts=4:et: