Ojs\JournalBundle\Controller\ArticleSubmissionController::previewAction PHP Method

    public function previewAction(Request $request, $articleId)
    {
        $journal = $this->get('ojs.journal_service')->getSelectedJournal();
        if ($this->submissionsNotAllowed($request)) {
            return $this->respondAsNotAllowed();
        }
        $em = $this->getDoctrine()->getManager();
        $dispatcher = $this->get('event_dispatcher');
        $session = $this->get('session');
        /** @var User $user */
        $user = $this->getUser();
        if (!$journal) {
            $this->throw404IfNotFound($journal);
        }
        /** @var ArticleRepository $articleRepository */
        $articleRepository = $em->getRepository('OjsJournalBundle:Article');
        /** @var Article $article */
        $article = $articleRepository->findOneBy(array('id' => $articleId, 'submitterUser' => $user, 'status' => ArticleStatuses::STATUS_NOT_SUBMITTED));
        $this->throw404IfNotFound($article);
        $form = $this->createForm(new ArticlePreviewType(), $article, array('action' => $this->generateUrl('ojs_journal_submission_preview', array('journalId' => $journal->getId(), 'articleId' => $article->getId())), 'method' => 'POST'))->add('submit', 'submit', array('label' => 'article.submit', 'attr' => ['class' => 'btn-block']));
        $form->handleRequest($request);
        $validator = $this->get('validator');
        $draftErrors = $validator->validate($article, null, ['groups' => 'submission']);
        $submissionSetting = $em->getRepository('OjsJournalBundle:SubmissionSetting')->findOneBy([]);
        if ($form->isValid() && count($draftErrors) == 0) {
            if ($session->has('submissionFiles')) {
                $session->remove('submissionFiles');
            }
            $article->setStatus(ArticleStatuses::STATUS_PUBLISH_READY);
            $article->setSubmissionDate(new \DateTime());
            $em->persist($article);
            // Assign user to author journal role
            /** @var Role $role */
            $role = $em->getRepository('OjsUserBundle:Role')->findOneBy(['role' => 'ROLE_AUTHOR']);
            /** @var JournalUser $journalUser */
            $journalUser = $em->getRepository('OjsJournalBundle:JournalUser')->findOneBy(array('user' => $user));
            if (!$journalUser) {
                $journalUser = new JournalUser();
                $journalUser->setJournal($journal)->setUser($user);
            }
            $journalUser->addRole($role);
            $em->persist($journalUser);
            $em->flush();
            $response = $this->redirectToRoute('ojs_journal_submission_me', ['journalId' => $article->getJournal()->getId()]);
            $event = new JournalItemEvent($article);
            $dispatcher->dispatch(ArticleEvents::POST_SUBMIT, $event);
            if (null !== $event->getResponse()) {
                return $event->getResponse();
            }
            return $response;
        }
        return $this->render('OjsJournalBundle:ArticleSubmission:preview.html.twig', array('article' => $article, 'journal' => $journal, 'translations' => $article->getTranslations(), 'fileTypes' => ArticleFileParams::$FILE_TYPES, 'form' => $form->createView(), 'submissionSetting' => $submissionSetting, 'draftErrors' => $draftErrors));
    }