public function onIssueView(ViewIssueEvent $event)
{
$issue = $event->getIssue();
$stat = $this->em->getRepository('OjsAnalyticsBundle:IssueStatistic')->findOneBy(['date' => new \DateTime(), 'issue' => $issue]);
if (!$stat) {
$stat = new IssueStatistic();
$stat->setDate(new \DateTime());
$stat->setIssue($issue);
$stat->setView(1);
} else {
$stat->setView($stat->getView() + 1);
}
$issue->increaseViewCount();
$this->em->persist($issue);
$this->em->persist($stat);
$this->em->flush();
}