OJSPaymentManager::membershipEnabled PHP Method

    function membershipEnabled()
    {
        $journal = $this->request->getJournal();
        return $this->isConfigured() && $journal->getSetting('membershipFeeEnabled') && $journal->getSetting('membershipFee') > 0;
    }

 /**
  * Validation
  * @see lib/pkp/classes/handler/PKPHandler#validate()
  * @param $request Request
  * @param $issueId int
  * @param $galleyId int
  */
 function validate($request, $issueId = null, $galleyId = null)
 {
     $returner = parent::validate(null, $request);
     // Validate requests that don't specify an issue or galley
     if (!$issueId && !$galleyId) {
         return $returner;
     }
     // Require an issue id to continue
     if (!$issueId) {
         $request->redirect(null, 'index');
     }
     import('classes.issue.IssueAction');
     $journal =& $request->getJournal();
     $journalId = $journal->getId();
     $user =& $request->getUser();
     $userId = $user ? $user->getId() : 0;
     $issue = null;
     $galley = null;
     // Get the issue
     $issueDao =& DAORegistry::getDAO('IssueDAO');
     if ($journal->getSetting('enablePublicIssueId')) {
         $issue =& $issueDao->getIssueByBestIssueId($issueId, $journalId);
     } else {
         $issue =& $issueDao->getIssueById((int) $issueId, null, true);
     }
     // Invalid issue id, redirect to current issue
     if (!$issue || !$this->_isVisibleIssue($issue, $journalId)) {
         $request->redirect(null, null, 'current');
     }
     $this->setIssue($issue);
     // If no issue galley id provided, then we're done
     if (!$galleyId) {
         return true;
     }
     // Get the issue galley
     $galleyDao =& DAORegistry::getDAO('IssueGalleyDAO');
     if ($journal->getSetting('enablePublicGalleyId')) {
         $galley =& $galleyDao->getGalleyByBestGalleyId($galleyId, $issue->getId());
     } else {
         $galley =& $galleyDao->getGalley($galleyId, $issue->getId());
     }
     // Invalid galley id, redirect to issue page
     if (!$galley) {
         $request->redirect(null, null, 'view', $issueId);
     }
     $this->setGalley($galley);
     // If this is an editorial user who can view unpublished issue galleys,
     // bypass further validation
     if (IssueAction::allowedIssuePrePublicationAccess($journal)) {
         return true;
     }
     // Ensure reader has rights to view the issue galley
     if ($issue->getPublished()) {
         $subscriptionRequired = IssueAction::subscriptionRequired($issue);
         $isSubscribedDomain = IssueAction::subscribedDomain($journal, $issueId);
         // Check if login is required for viewing.
         if (!$isSubscribedDomain && !Validation::isLoggedIn() && $journal->getSetting('restrictArticleAccess')) {
             Validation::redirectLogin();
         }
         // If no domain/ip subscription, check if user has a valid subscription
         // or if the user has previously purchased the issue
         if (!$isSubscribedDomain && $subscriptionRequired) {
             // Check if user has a valid subscription
             $subscribedUser = IssueAction::subscribedUser($journal, $issueId);
             if (!$subscribedUser) {
                 // Check if payments are enabled,
                 import('classes.payment.ojs.OJSPaymentManager');
                 $paymentManager = new OJSPaymentManager($request);
                 if ($paymentManager->purchaseIssueEnabled() || $paymentManager->membershipEnabled()) {
                     // If only pdf files are being restricted, then approve all non-pdf galleys
                     // and continue checking if it is a pdf galley
                     if ($paymentManager->onlyPdfEnabled() && !$galley->isPdfGalley()) {
                         return true;
                     }
                     if (!Validation::isLoggedIn()) {
                         Validation::redirectLogin("payment.loginRequired.forIssue");
                     }
                     // If the issue galley has been purchased, then allow reader access
                     $completedPaymentDao =& DAORegistry::getDAO('OJSCompletedPaymentDAO');
                     $dateEndMembership = $user->getSetting('dateEndMembership', 0);
                     if ($completedPaymentDao->hasPaidPurchaseIssue($userId, $issueId) || !is_null($dateEndMembership) && $dateEndMembership > time()) {
                         return true;
                     } else {
                         // Otherwise queue an issue purchase payment and display payment form
                         $queuedPayment =& $paymentManager->createQueuedPayment($journalId, PAYMENT_TYPE_PURCHASE_ISSUE, $userId, $issueId, $journal->getSetting('purchaseIssueFee'));
                         $queuedPaymentId = $paymentManager->queuePayment($queuedPayment);
                         $templateMgr =& TemplateManager::getManager();
                         $paymentManager->displayPaymentForm($queuedPaymentId, $queuedPayment);
                         exit;
                     }
                 }
                 if (!Validation::isLoggedIn()) {
                     Validation::redirectLogin("reader.subscriptionRequiredLoginText");
                 }
                 $request->redirect(null, 'about', 'subscriptions');
             }
         }
     } else {
         $request->redirect(null, 'index');
     }
     return true;
 }