# -*- coding: UTF-8 -*-
from models import Statuses, Item, Company, Invoice
from observers import EmailSender, Imprint
# Observer is a behavioral design pattern that
# lets you define a subscription mechanism to
# notify multiple objects about any events that
# happen to the object they’re observing.
if __name__ == "__main__":
items = [Item('ITEM A', 100), Item('ITEM B', 200)]
provider = Company('012345678901234', 'Guido')
subject = Invoice(company=provider, items=items)
notification = EmailSender()
subject.attach(notification)
printer = Imprint()
subject.attach(printer)
subject.update('deferred')
subject.detach(printer)
subject.update('rejected')
