1SignalReceiver.py

from django.db.models.signals import *

class UserNotPresentError(Exception):
	pass
	
class SignalNotSpecifiedError(Exception):
	pass

class SignalReceiver(object):
	user = None
	signal = None
	sender = None
	action = None
	extra = None
	obj = None
	
	def __init__(self):
		self.pre = None
		for k, v in self.__class__.__dict__.iteritems():
			if isinstance(v, str):
				self.__dict__[k] = v
		
		if isinstance(self.signal, tuple):
			self.signal[0].connect(self.precall, sender = self.sender)
			self.signal[1].connect(self.call, sender = self.sender)
		else:
			self.signal.connect(self.call, sender = self.sender)
	
	def call(self, sender, **kwargs):
		if self.test(sender, **kwargs):
			if 'instance' in kwargs:
				if not self.obj:
					self.obj = kwargs['instance']
				
				if not self.user:
					try:
						self.user = kwargs['instance'].user
					except AttributeError:
						raise UserNotPresentError
				
			elif not self.user:
				raise UserNotPresentError
							
			h = History(user = self.user, action = self.action, obj = self.obj, extra = self.extra)
			h.save()
			
	def test(self, sender):
		return False
						
	def __str__(self):
		if '%' in self.message:
			return self.message%self.__dict__
		return self.message

2sample_class.py

class CommentCreatedReceiver(SignalReceiver):
	signal = post_save
	sender = Comment
	action = 'articles_add_comment'
	message = 'added an answer'
	icon_name = 'add_comment'
	
	def test(self, sender, **kwargs):
		return kwargs['created']

	def __str__(self):
		if self.obj:
			return 'answered (%(perm)s") to %(title)s (%(pperm)s)' %{"perm": self.obj.get_absolute_url(), "pperm": self.obj.obj.get_absolute_url(), "title": self.obj.obj}
		else:
			return super(CommentCreatedReceiver, self).__str__()

3sample_class_pre.py

class AddressChangedReceiver(SignalReceiver):
	signal = profile_pre_edit, profile_edited
	sender = UserProfile
	action = 'accounts_address_changed'
	message = 'updated address'
	icon_name = 'map_edit'
	
	pre = None
	def precall(self, sender, **kwargs):
		self.pre = kwargs['instance'].address
		self.extra = kwargs['instance'].location + ';' + kwargs['instance'].address
		
	def test(self, sender, **kwargs):
		if self.pre!=kwargs['instance'].address:
			return True
			
		return False

4Binder.py

class Binder(object):
	classlist = [ AddressChangedReceiver, CommentCreatedReceiver]

	receivers = dict([(r.action, r()) for r in classlist])