def execute(self, dbSession, telegram, peer, arguments):
if not len(arguments) == 2:
telegram.send_msg(peer.id, 'Wrong number of arguments.')
return
if not self._isUserAuthorized(dbSession, peer):
telegram.send_msg(peer.id, 'Not authorized.')
return
if self._subscriptionExists(dbSession, telegram, peer, arguments[0]):
telegram.send_msg(peer.id, 'You are already subscribed to this URL.')
return
try:
if not WHCrawlFactory.crawlerExists(arguments[0]):
raise Exception("Could not find a suitable crawler for the site provided!")
if not WHCrawlFactory.isCrawlingPeriodValid(arguments[0], int(arguments[1])):
raise Exception("Given crawling period is not valid.")
# add URL
urlId = self._makeSureUrlExists(dbSession, arguments[0])
# add Subscription of user to URL
subscription = Subscription(user_id=self._queryUser(dbSession, peer).id, url_id=urlId, query_period=int(arguments[1]))
dbSession.add(subscription)
dbSession.commit()
telegram.send_msg(peer.id, 'URL added successfully.')
except Exception as exc:
telegram.send_msg(peer.id, "Could not add URL: {0}".format(exc))
dbSession.rollback()
def processSubscriptions(self, dbSession):
now = datetime.datetime.now()
# iterate through subscriptions
for user, subscription, subscription_url in dbSession.query(User, Subscription, Url).filter(User.id == Subscription.user_id).filter(Subscription.url_id == Url.id).all():
# determine which subscriptions have to be queried again
if self.__isSubscriptionDue(now, subscription):
# query relevant subscription pages
crawler = WHCrawlFactory.getCrawler(subscription_url.location)
self.__processOffers(crawler.crawl(), dbSession, user, subscription)
# update last_query to now
subscription.last_query = now
dbSession.commit()