wtf_you_want.py

import datetime

class BaseNotification(object):
    def __init__(self, **kwargs):
        for k, v in kwargs.items():
            setattr(self, k, v) 
                                                                                   
        if 'timestamp' in kwargs.keys():
            self.sent_at = datetime.datetime.fromtimestamp(kwargs['timestamp'])

    def to_dict(self, user):
        return {
            'timestamp': self.timestamp,
        }  

    def get_display(self, user, backend):
        raise NotImplementedError()

class TextNotification(BaseNotification):
    def to_dict(self, user):
        data = super(TextNotification, self).to_dict(user, sent_at)
        data['text'] = self.text % self.format_kwargs
        return data

    def get_display(self, user, backend):
        return self.text

class LazyTextNotification(TextNotification):
    def to_dict(self, user):
        data = super(TextNotification, self).to_dict(user, sent_at)
        data['text'] = self.text
        data['format_kwargs'] = self.format_kwargs
        return  data

    def get_display(self, user, backend):
        return self.text % self.format_kwargs

class WikiSyntaxNotification(object):
    # create ;)

class TemplateNotification(object):
    # create ;)

# example:
def emit_new_follower(user, follower):
    Subscription.objects.emit(TextNotification(
            text='%(follower)s follows %(user)s',
            format_kwargs={
                'user': user,
                'follower': follower,
            }
        ))
        subscribers_of=[follower, user],
        queue='friends',
    )

# or wikisyntax
def emit_new_follower(user, follower):
    Subscription.objects.emit(TextNotification(
            text='[[%s]] follows [[%s]]' % (follower, user),
            **{
                user.username: user,
                follower.username: follower,
            }
        ))
        subscribers_of=[follower, user],
        queue='friends',
    )

# or with template:
def emit_new_follower(user, follower):
    Subscription.objects.emit(TemplateNotification(
            type='new_follower',
            context={
                'user':user,
                'follower':follower
            },
        ))
        subscribers_of=[follower, user],
        queue='friends',
    )