/**
  * Update event from db
  *
  * @param EventForm $eventForm
  * @param Event     $event
  * @param User      $user
  */
 public function saveEventOnUpdate(EventForm $eventForm, Event $event, User $user)
 {
     $groupRepository = $this->entityManager->getRepository('AppBundle:Group');
     /** @var Event $event */
     $event->setName($eventForm->getName())->setDescription($eventForm->getDescription())->setCountry($eventForm->getCountry())->setCity($eventForm->getCity())->setAddress($eventForm->getAddress())->setBeginAt($eventForm->getBeginAt())->setEndAt($eventForm->getEndAt())->setSlug($eventForm->getName())->setUpdatedBy($user);
     $this->entityManager->persist($event);
     $groups = $groupRepository->findGroupsByEvent($event);
     /** @var Group $groupElement */
     foreach ($eventForm->getGroups() as $groupElement) {
         $group = $groupRepository->findOneBy(['slug' => $groupElement->getSlug()]);
         if (!in_array($group, $groups)) {
             $eventGroups = (new EventGroup())->setEvent($event)->setGroup($group);
             $this->entityManager->persist($eventGroups);
         }
     }
     $this->entityManager->flush();
 }