pluginLoader.py

#!/usr/bin/python
# -*- coding: UTF-8 -*-

"""
Functions to Load and import the Plugins

@author: Bastian Schroll

@requires: Configuration has to be set in the config.ini
"""

import logging # Global logger
import imp
import os

from ConfigParser import NoOptionError # we need this exception
from includes import globalVars  # Global variables

def loadPlugins():
	"""
	Load all plugins into globalVars.pluginList

	@return:    nothing
	@exception: Exception if insert into globalVars.pluginList failed
	"""
	try:
		logging.debug("loading plugins")
		# go to all Plugins from getPlugins()
		for i in getPlugins():
			try:
				# call for each Plugin the loadPlugin() Methode
				plugin = loadPlugin(i)
			except:
				# call next plugin, if one has thrown an exception
				logging.error("error loading plugin: %s", i["name"])
				logging.debug("error loading plugin: %s", i["name"], exc_info=True)
			else: # only call onLoad() and insert into pluginList[] if import is succesfull

				try:
					# Try to call the .onLoad() routine for all active plugins
					logging.debug("call %s.onLoad()", i["name"])
					plugin.onLoad()
					# Add it to globalVars.pluginList
					globalVars.pluginList[i["name"]] = plugin
				except:
					# call next plugin, if one has thrown an exception
					logging.error("error calling %s.onLoad()", i["name"])
					logging.debug("error calling %s.onLoad()", exc_info=True)
	except:
		logging.error("cannot load plugins")
		logging.debug("cannot load plugins", exc_info=True)
		raise


def getPlugins():
	"""
	get a Python Dict of all activeated plugins

	@return:    plugins as Python Dict
	@exception: Exception if plugin search failed
	"""
	try:
		logging.debug("Search in plugin folder")
		PluginFolder = globalVars.script_path+"/plugins"
		plugins = []
		# Go to all Folders in the Plugin-Dir
		for i in os.listdir(PluginFolder):
			location = os.path.join(PluginFolder, i)

			# Skip if Path.isdir() or no File DIR_NAME.py is found
			if not os.path.isdir(location) or not i + ".py" in os.listdir(location):
				continue

			# is the plugin enabled in the config-file?
			try:
				if globalVars.config.getint("Plugins", i):
					info = imp.find_module(i, [location])
					plugins.append({"name": i, "info": info})
					logging.debug("Plugin [ENABLED ] %s", i)
				else:
					logging.debug("Plugin [DISABLED] %s ", i)
			# no entry for plugin found in config-file
			except NoOptionError:
				logging.warning("Plugin [NO CONF ] %s", i)
	except:
		logging.error("Error during plugin search")
		logging.debug("Error during plugin search", exc_info=True)
		raise

	return plugins


def loadPlugin(plugin):
	"""
	Imports a single plugin

	@type    plugin: plugin Data
	@param   plugin: Contains the information to import a plugin


	@return:    nothing
	@exception: Exception if plugin import failed
	"""
	try:
		logging.debug("load plugin: %s", plugin["name"])
		return imp.load_module(plugin["name"], *plugin["info"])
	except:
		logging.error("cannot load plugin: %s", plugin["name"])
		logging.debug("cannot load plugin: %s", plugin["name"], exc_info=True)
		raise