def update(self):
context = self.context
mtool = getToolByName(context, 'portal_membership')
self.uid = IUIDStrategy(context).getuid()
self.container = queryUtility(ISubscribers)
self.utility = getUtility(IDigestUtility)
self.catalog = queryUtility(ISubscriptionCatalog)
self.user = mtool.getAuthenticatedMember()
self.user_id = self.user.getId()
self.subscriber = ItemSubscriber(user=self.user_id)
self.subscribed_daily = ('member', self.user_id) in self.catalog.search({'daily-digest': self.uid})
self.subscribed_weekly = ('member', self.user_id) in self.catalog.search({'weekly-digest': self.uid})
self.subscribed_nothing = not (self.subscribed_daily or self.subscribed_weekly)
