#

# Copyright (c) 2008-2009 Nokia Corporation and/or its subsidiary(-ies).

# All rights reserved.

# This component and the accompanying materials are made available

# under the terms of the License "Eclipse Public License v1.0"

# which accompanies this distribution, and is available

# at the URL "http://www.eclipse.org/legal/epl-v10.html".

#

# Initial Contributors:

# Nokia Corporation - initial contribution.

#

# Contributors:

#

# Description: 

# PluginBox module - finds classes 

#

from os import listdir

import re

from types import TypeType, ModuleType

import sys

class PluginModule(object):

	"""Represents a module containing plugin classes """

	def __init__(self, file):

		self.module = __import__(file)

		self.classes = []

		self.__findclasses(self.module)

	def __findclasses(self,module):

		for c in module.__dict__:

			mbr = module.__dict__[c]

			if type(mbr) == TypeType:

				self.classes.append(mbr)

class PluginBox(object):

	"""

	A container that locates all the classes in a directory.

	Example usage:

		from person import Person

		ps = PluginBox("plugins")

		people = []

		for i in ps.classesof(Person):

			people.append(i())

	"""

	plugfilenamere=re.compile('^(.*)\.py$',re.I)

	def __init__(self, plugindirectory):

		self.pluginlist = []

		self.plugindir = plugindirectory

		sys.path.append(str(self.plugindir))

		for f in listdir(plugindirectory):

			m = PluginBox.plugfilenamere.match(f)

			if m is not None:

				self.pluginlist.append(PluginModule(m.groups()[0]))

		sys.path = sys.path[:-1]

	def classesof(self, classtype):

		"""return a list of all classes that are subclasses of <classtype>"""

		classes = []

		for p in self.pluginlist:

			for c in p.classes:

				if issubclass(c, classtype):

					if c.__name__ != classtype.__name__:

						classes.append(c)

		return classes