Merge pull request #4668 from AngelFQC/BT20637

Calendar: Add agenda_event_subscriptions configuration setting

main/calendar/agenda.php

@@ -174,6 +174,9 @@ if ($allowToEdit) {
                 $notificationPeriod = $_REQUEST['notification_period'] ?? [];
                 $careerId = $_REQUEST['career_id'] ?? 0;
                 $promotionId = $_REQUEST['promotion_id'] ?? 0;
+                $subscriptionVisibility = (int) ($_REQUEST['subscription_visibility'] ?? 0);
+                $subscriptionItemId = isset($_REQUEST['subscription_item']) ? (int) $_REQUEST['subscription_item'] : null;
+                $maxSubscriptions = (int) ($_REQUEST['max_subscriptions'] ?? 0);
 
                 $reminders = $notificationCount ? array_map(null, $notificationCount, $notificationPeriod) : [];
 
@@ -194,7 +197,10 @@ if ($allowToEdit) {
                     $values['collective'] ?? false,
                     $reminders,
                     (int) $careerId,
-                    (int) $promotionId
+                    (int) $promotionId,
+                    $subscriptionVisibility,
+                    $subscriptionItemId,
+                    $maxSubscriptions
                 );
 
                 if (!empty($values['repeat']) && !empty($eventId)) {
@@ -254,6 +260,10 @@ if ($allowToEdit) {
                 $notificationPeriod = $_REQUEST['notification_period'] ?? [];
                 $careerId = $_REQUEST['career_id'] ?? 0;
                 $promotionId = $_REQUEST['promotion_id'] ?? 0;
+                $subscriptionVisibility = (int) ($_REQUEST['subscription_visibility'] ?? 0);
+                $subscriptionItemId = isset($_REQUEST['subscription_item']) ? (int) $_REQUEST['subscription_item'] : null;
+                $maxSubscriptions = (int) ($_REQUEST['max_subscriptions'] ?? 0);
+                $subscribers = $_REQUEST['subscribers'] ?? [];
 
                 $reminders = $notificationCount ? array_map(null, $notificationCount, $notificationPeriod) : [];
 
@@ -307,7 +317,11 @@ if ($allowToEdit) {
                     $values['collective'] ?? false,
                     $reminders,
                     (int) $careerId,
-                    (int) $promotionId
+                    (int) $promotionId,
+                    $subscriptionVisibility,
+                    $subscriptionItemId,
+                    $maxSubscriptions,
+                    $subscribers
                 );
 
                 if (!empty($values['repeat']) && !empty($eventId)) {

main/calendar/agenda_js.php

@@ -3,6 +3,8 @@
 /* For licensing terms, see /license.txt */
 
 // use anonymous mode when accessing this course tool
+use Chamilo\CoreBundle\Entity\AgendaEventSubscription;
+
 $use_anonymous = true;
 $typeList = ['personal', 'course', 'admin', 'platform'];
 // Calendar type
@@ -237,6 +239,7 @@ $form = new FormValidator(
     null,
     ['id' => 'add_event_form']
 );
+$form->addHeader(get_lang('Events'));
 
 $form->addHtml('<span id="calendar_course_info"></span><div id="visible_to_input">');
 
@@ -280,6 +283,7 @@ if ('course' === $agenda->type) {
 }
 
 if (api_get_configuration_value('agenda_collective_invitations') && 'personal' === $agenda->type) {
+    $form->addHeader(get_lang('Invitations'));
     $form->addSelectAjax(
         'invitees',
         get_lang('Invitees'),
@@ -292,6 +296,48 @@ if (api_get_configuration_value('agenda_collective_invitations') && 'personal' =
     $form->addCheckBox('collective', '', get_lang('IsItEditableByTheInvitees'));
 }
 
+if (
+    api_is_platform_admin()
+    && api_get_configuration_value('agenda_event_subscriptions') && 'personal' === $agenda->type
+) {
+    $form->addHeader(get_lang('Subscriptions'));
+    $form->addHtml('<div id="form_subscriptions_container" style="position: relative;">');
+    $form->addSelect(
+        'subscription_visibility',
+        get_lang('AllowSubscriptions'),
+        [
+            AgendaEventSubscription::SUBSCRIPTION_NO => get_lang('No'),
+            AgendaEventSubscription::SUBSCRIPTION_ALL => get_lang('AllUsersOfThePlatform'),
+            AgendaEventSubscription::SUBSCRIPTION_CLASS => get_lang('UsersInsideClass'),
+        ],
+        [
+            'onchange' => 'document.getElementById(\'max_subscriptions\').disabled = this.value == 0; document.getElementById(\'form_subscription_item\').disabled = this.value != 2',
+        ]
+    );
+    $form->addSelectAjax(
+        'subscription_item',
+        get_lang('SocialGroup').' / '.get_lang('Class'),
+        [],
+        [
+            'url' => api_get_path(WEB_AJAX_PATH).'usergroup.ajax.php?a=get_class_by_keyword',
+            'disabled' => 'disabled',
+            'dropdownParent' => '#form_subscriptions_container',
+        ]
+    );
+    $form->addNumeric(
+        'max_subscriptions',
+        ['', get_lang('MaxSubscriptionsLeaveEmptyToNotLimit')],
+        [
+            'disabled' => 'disabled',
+            'step' => 1,
+            'min' => 0,
+            'value' => 0,
+        ]
+    );
+    $form->addHtml('</div>');
+    $form->addHtml('<div id="form_subscriptions_edit" style="display: none;"></div>');
+}
+
 if (api_get_configuration_value('agenda_reminders')) {
     $tpl->assign(
         'agenda_reminders_js',
@@ -309,6 +355,7 @@ if (api_get_configuration_value('allow_careers_in_global_agenda') && 'admin' ===
 }
 
 $form->addHtml('<div id="attachment_block" style="display: none">');
+$form->addHeader(get_lang('FilesAttachment'));
 $form->addLabel(get_lang('Attachment'), '<div id="attachment_text" style="display: none"></div>');
 $form->addHtml('</div>');
 

main/inc/ajax/agenda.ajax.php

@@ -51,6 +51,8 @@ switch ($action) {
         $notificationPeriod = $_REQUEST['notification_period'] ?? [];
         $careerId = $_REQUEST['career_id'] ?? 0;
         $promotionId = $_REQUEST['promotion_id'] ?? 0;
+        $subscriptionVisibility = (int) ($_REQUEST['subscription_visibility'] ?? 0);
+        $maxSubscriptions = (int) ($_REQUEST['max_subscriptions'] ?? 0);
 
         $reminders = $notificationCount ? array_map(null, $notificationCount, $notificationPeriod) : [];
 
@@ -71,7 +73,9 @@ switch ($action) {
             $isCollective,
             $reminders,
             (int) $careerId,
-            (int) $promotionId
+            (int) $promotionId,
+            $subscriptionVisibility,
+            $maxSubscriptions
         );
 
         echo $eventId;
@@ -224,6 +228,32 @@ switch ($action) {
             );
         }
         break;
+    case 'event_subscribe':
+        if (!$agenda->getIsAllowedToEdit()) {
+            break;
+        }
+
+        if (false === Security::check_token('get')) {
+            exit;
+        }
+
+        $id = (int) explode('_', $_REQUEST['id'])[1];
+
+        $agenda->subscribeCurrentUserToEvent($id);
+        break;
+    case 'event_unsubscribe':
+        if (!$agenda->getIsAllowedToEdit()) {
+            break;
+        }
+
+        if (false === Security::check_token('get')) {
+            exit;
+        }
+
+        $id = (int) explode('_', $_REQUEST['id'])[1];
+
+        $agenda->unsubscribeCurrentUserToEvent($id);
+        break;
     default:
         echo '';
 }

main/inc/lib/agenda.lib.php

@@ -4,7 +4,10 @@
 
 use Chamilo\CoreBundle\Entity\AgendaEventInvitation;
 use Chamilo\CoreBundle\Entity\AgendaEventInvitee;
+use Chamilo\CoreBundle\Entity\AgendaEventSubscriber;
+use Chamilo\CoreBundle\Entity\AgendaEventSubscription;
 use Chamilo\CoreBundle\Entity\AgendaReminder;
+use Chamilo\CoreBundle\Entity\PersonalAgenda;
 use Chamilo\UserBundle\Entity\User;
 
 /**
@@ -254,13 +257,18 @@ class Agenda
         bool $isCollective = false,
         array $reminders = [],
         int $careerId = 0,
-        int $promotionId = 0
+        int $promotionId = 0,
+        int $subscriptionVisibility = 0,
+        ?int $subscriptionItemId = null,
+        int $maxSubscriptions = 0
     ) {
         $start = api_get_utc_datetime($start);
         $end = api_get_utc_datetime($end);
         $allDay = isset($allDay) && ($allDay === 'true' || $allDay == 1) ? 1 : 0;
         $id = null;
 
+        $em = Database::getManager();
+
         switch ($this->type) {
             case 'personal':
                 $attributes = [
@@ -281,6 +289,26 @@ class Agenda
                 if (api_get_configuration_value('agenda_collective_invitations')) {
                     Agenda::saveCollectiveProperties($inviteesList, $isCollective, $id);
                 }
+
+                if (api_get_configuration_value('agenda_event_subscriptions') && api_is_platform_admin()) {
+                    $personalEvent = $em->find(PersonalAgenda::class, $id);
+                    $personalEvent
+                        ->setSubscriptionVisibility($subscriptionVisibility)
+                        ->setSubscriptionItemId($subscriptionItemId ?: null)
+                    ;
+
+                    $subscription = (new AgendaEventSubscription())
+                        ->setCreator(api_get_user_entity(api_get_user_id()))
+                        ->setMaxAttendees($subscriptionVisibility > 0 ? $maxSubscriptions : 0)
+                    ;
+
+                    $personalEvent
+                        ->setCollective(false)
+                        ->setInvitation($subscription)
+                    ;
+
+                    $em->flush();
+                }
                 break;
             case 'course':
                 $attributes = [
@@ -865,7 +893,11 @@ class Agenda
         bool $isCollective = false,
         array $remindersList = [],
         int $careerId = 0,
-        int $promotionId = 0
+        int $promotionId = 0,
+        int $subscriptionVisibility = 0,
+        ?int $subscriptionItemId = null,
+        int $maxSubscriptions = 0,
+        array $subscribers = []
     ) {
         $id = (int) $id;
         $start = api_get_utc_datetime($start);
@@ -874,6 +906,8 @@ class Agenda
         $currentUserId = api_get_user_id();
         $authorId = empty($authorId) ? $currentUserId : (int) $authorId;
 
+        $em = Database::getManager();
+
         switch ($this->type) {
             case 'personal':
                 $eventInfo = $this->get_event($id);
@@ -909,6 +943,24 @@ class Agenda
                 if (api_get_configuration_value('agenda_collective_invitations')) {
                     Agenda::saveCollectiveProperties($inviteesList, $isCollective, $id);
                 }
+
+                if (api_get_configuration_value('agenda_event_subscriptions') && api_is_platform_admin()) {
+                    $personalEvent = $em->find(PersonalAgenda::class, $id);
+                    $personalEvent->setSubscriptionVisibility($subscriptionVisibility);
+
+                    /** @var AgendaEventSubscription $subscription */
+                    $subscription = $personalEvent->getInvitation();
+                    $subscription->setMaxAttendees($subscriptionVisibility > 0 ? $maxSubscriptions : 0);
+
+                    if ($personalEvent->getSubscriptionItemId() != $subscriptionItemId) {
+                        $personalEvent->setSubscriptionItemId($subscriptionItemId ?: null);
+                        $subscription->removeInvitees();
+                    } else {
+                        $subscription->removeInviteesNotInIdList($subscribers);
+                    }
+
+                    $em->flush();
+                }
                 break;
             case 'course':
                 $eventInfo = $this->get_event($id);
@@ -1306,6 +1358,80 @@ class Agenda
         }
     }
 
+    public function subscribeCurrentUserToEvent(int $id)
+    {
+        if (false === api_get_configuration_value('agenda_event_subscriptions')) {
+            return;
+        }
+
+        if ('personal' !== $this->type) {
+            return;
+        }
+
+        $em = Database::getManager();
+
+        $currentUser = api_get_user_entity(api_get_user_id());
+        $personalEvent = $em->find(PersonalAgenda::class, $id);
+
+        /** @var AgendaEventSubscription $subscription */
+        $subscription = $personalEvent ? $personalEvent->getInvitation() : null;
+
+        if (!$subscription) {
+            return;
+        }
+
+        if ($subscription->getInvitees()->count() >= $subscription->getMaxAttendees()
+            && $subscription->getMaxAttendees() > 0
+        ) {
+            return;
+        }
+
+        if (AgendaEventSubscription::SUBSCRIPTION_CLASS === $personalEvent->getSubscriptionVisibility()) {
+            $objGroup = new UserGroup();
+            $groupList = $objGroup->getUserGroupListByUser($currentUser->getId(), UserGroup::NORMAL_CLASS);
+            $groupIdList = array_column($groupList, 'id');
+
+            if (!in_array($personalEvent->getSubscriptionItemId(), $groupIdList)) {
+                return;
+            }
+        }
+
+        $subscriber = (new AgendaEventSubscriber())
+            ->setUser($currentUser)
+        ;
+
+        $subscription->addInvitee($subscriber);
+
+        $em->flush();
+    }
+
+    public function unsubscribeCurrentUserToEvent(int $id)
+    {
+        if (false === api_get_configuration_value('agenda_event_subscriptions')) {
+            return;
+        }
+
+        if ('personal' !== $this->type) {
+            return;
+        }
+
+        $em = Database::getManager();
+
+        $currentUser = api_get_user_entity(api_get_user_id());
+        $personalEvent = $em->find(PersonalAgenda::class, $id);
+
+        /** @var AgendaEventSubscription $subscription */
+        $subscription = $personalEvent ? $personalEvent->getInvitation() : null;
+
+        if (!$subscription) {
+            return;
+        }
+
+        $subscription->removeInviteeUser($currentUser);
+
+        $em->flush();
+    }
+
     /**
      * Get agenda events.
      *
@@ -1759,56 +1885,113 @@ class Agenda
         $endCondition = '';
 
         $agendaCollectiveInvitations = api_get_configuration_value('agenda_collective_invitations');
+        $agendaEventSubscriptions = api_get_configuration_value('agenda_event_subscriptions');
+        $userIsAdmin = api_is_platform_admin();
+
+        $queryParams = [];
 
         if ($start !== 0) {
-            $startDate = api_get_utc_datetime($start, true, true);
-            $startCondition = "AND date >= '".$startDate->format('Y-m-d H:i:s')."'";
+            $queryParams['start_date'] = api_get_utc_datetime($start, true, true);
+            $startCondition = "AND pa.date >= :start_date";
         }
         if ($end !== 0) {
-            $endDate = api_get_utc_datetime($end, false, true);
-            $endCondition = "AND (enddate <= '".$endDate->format('Y-m-d H:i:s')."' OR enddate IS NULL)";
+            $queryParams['end_date'] = api_get_utc_datetime($end, false, true);
+            $endCondition = "AND (pa.enddate <= :end_date OR pa.enddate IS NULL)";
         }
         $user_id = api_get_user_id();
 
-        $sql = "SELECT * FROM ".$this->tbl_personal_agenda."
-                WHERE user = $user_id $startCondition $endCondition";
+        $queryParams['user_id'] = $user_id;
+        $userCondition = "pa.user = :user_id";
+
+        $objGroup = new UserGroup();
+
+        if ($agendaEventSubscriptions) {
+            $groupList = $objGroup->getUserGroupListByUser($user_id, UserGroup::NORMAL_CLASS);
+
+            $userCondition = "(
+                    $userCondition
+                    OR (
+                        pa.subscriptionVisibility = ".AgendaEventSubscription::SUBSCRIPTION_ALL;
+
+            if ($groupList) {
+                $userCondition .= "
+                        OR (
+                            pa.subscriptionVisibility = ".AgendaEventSubscription::SUBSCRIPTION_CLASS."
+                            AND pa.subscriptionItemId IN (".implode(', ', array_column($groupList, 'id')).")
+                        ) 
+                ";
+            }
+
+            $userCondition .= "
+                    )
+                )
+            ";
+        }
+
+        $sql = "SELECT pa FROM ChamiloCoreBundle:PersonalAgenda AS pa WHERE $userCondition $startCondition $endCondition";
+
+        $result = Database::getManager()
+            ->createQuery($sql)
+            ->setParameters($queryParams)
+            ->getResult();
 
-        $result = Database::query($sql);
         $my_events = [];
-        if (Database::num_rows($result)) {
-            while ($row = Database::fetch_array($result, 'ASSOC')) {
-                $event = [];
-                $event['id'] = 'personal_'.$row['id'];
-                $event['title'] = $row['title'];
-                $event['className'] = 'personal';
-                $event['borderColor'] = $event['backgroundColor'] = $this->event_personal_color;
-                $event['editable'] = true;
-                $event['sent_to'] = get_lang('Me');
-                $event['type'] = 'personal';
 
-                if (!empty($row['date'])) {
-                    $event['start'] = $this->formatEventDate($row['date']);
-                    $event['start_date_localtime'] = api_get_local_time($row['date']);
-                }
+        /** @var PersonalAgenda $row */
+        foreach ($result as $row) {
+            $event = [];
+            $event['id'] = 'personal_'.$row->getId();
+            $event['title'] = $row->getTitle();
+            $event['className'] = 'personal';
+            $event['borderColor'] = $event['backgroundColor'] = $this->event_personal_color;
+            $event['editable'] = $user_id === (int) $row->getUser();
+            $event['sent_to'] = get_lang('Me');
+            $event['type'] = 'personal';
+
+            if (!empty($row->getDate())) {
+                $event['start'] = $this->formatEventDate($row->getDate());
+                $event['start_date_localtime'] = api_get_local_time($row->getDate());
+            }
 
-                if (!empty($row['enddate'])) {
-                    $event['end'] = $this->formatEventDate($row['enddate']);
-                    $event['end_date_localtime'] = api_get_local_time($row['enddate']);
-                }
+            if (!empty($row->getEnddate())) {
+                $event['end'] = $this->formatEventDate($row->getEnddate());
+                $event['end_date_localtime'] = api_get_local_time($row->getEnddate());
+            }
 
-                $event['description'] = $row['text'];
-                $event['allDay'] = isset($row['all_day']) && $row['all_day'] == 1 ? $row['all_day'] : 0;
-                $event['parent_event_id'] = 0;
-                $event['has_children'] = 0;
+            $event['description'] = $row->getText();
+            $event['allDay'] = $row->getAllDay();
+            $event['parent_event_id'] = 0;
+            $event['has_children'] = 0;
 
-                if ($agendaCollectiveInvitations) {
-                    $event['collective'] = (bool) $row['collective'];
-                    $event['invitees'] = self::getInviteesForPersonalEvent($row['id']);
-                }
+            if ($agendaCollectiveInvitations || $agendaEventSubscriptions) {
+                $subscription = $row->getInvitation();
 
-                $my_events[] = $event;
-                $this->events[] = $event;
+                if ($subscription instanceof AgendaEventSubscription) {
+                    $subscribers = $subscription->getInvitees();
+
+                    $event['subscription_visibility'] = $row->getSubscriptionVisibility();
+                    $event['max_subscriptions'] = $subscription->getMaxAttendees();
+                    $event['can_subscribe'] = $subscribers->count() < $subscription->getMaxAttendees()
+                        || $subscription->getMaxAttendees() === 0;
+                    $event['user_is_subscribed'] = $subscription->hasUserAsInvitee(api_get_user_entity($user_id));
+                    $event['count_subscribers'] = $subscribers->count();
+
+                    if ($userIsAdmin) {
+                        $event['subscribers'] = self::getInviteesForPersonalEvent($row->getId(), AgendaEventSubscriber::class);
+                    }
+
+                    if (AgendaEventSubscription::SUBSCRIPTION_CLASS === $row->getSubscriptionVisibility()) {
+                        $groupInfo = $objGroup->get($row->getSubscriptionItemId());
+                        $event['usergroup'] = $groupInfo['name'];
+                    }
+                } else {
+                    $event['collective'] = $row->isCollective();
+                    $event['invitees'] = self::getInviteesForPersonalEvent($row->getId());
+                }
             }
+
+            $my_events[] = $event;
+            $this->events[] = $event;
         }
 
         if ($agendaCollectiveInvitations) {
@@ -1837,13 +2020,21 @@ class Agenda
         return $my_events;
     }
 
-    public static function getInviteesForPersonalEvent($eventId): array
+    public static function getInviteesForPersonalEvent($eventId, $type = AgendaEventInvitee::class): array
     {
         $em = Database::getManager();
         $event = $em->find('ChamiloCoreBundle:PersonalAgenda', $eventId);
 
-        $inviteeRepo = $em->getRepository('ChamiloCoreBundle:AgendaEventInvitee');
-        $invitees = $inviteeRepo->findByInvitation($event->getInvitation());
+        $invitation = $event->getInvitation();
+
+        if ($invitation instanceof AgendaEventSubscription
+            && AgendaEventInvitee::class === $type
+        ) {
+            return [];
+        }
+
+        $inviteeRepo = $em->getRepository($type);
+        $invitees = $inviteeRepo->findByInvitation($invitation);
 
         $inviteeList = [];
 
@@ -2680,6 +2871,9 @@ class Agenda
         $action = isset($params['action']) ? Security::remove_XSS($params['action']) : null;
         $id = isset($params['id']) ? (int) $params['id'] : 0;
 
+        $em = Database::getManager();
+        $personalEvent = 'personal' === $this->type && $id ? $em->find('ChamiloCoreBundle:PersonalAgenda', $id) : null;
+
         $url = api_get_self().'?action='.$action.'&id='.$id.'&type='.$this->type;
         if ($this->type == 'course') {
             $url = api_get_self().'?'.api_get_cidreq().'&action='.$action.'&id='.$id.'&type='.$this->type;
@@ -2894,16 +3088,15 @@ class Agenda
         $agendaCollectiveInvitations = api_get_configuration_value('agenda_collective_invitations');
 
         if ($agendaCollectiveInvitations && 'personal' === $this->type) {
-            $em = Database::getManager();
-
             $invitees = [];
             $isCollective = false;
+            $allowInvitees = true;
 
-            if ($id) {
-                $event = $em->find('ChamiloCoreBundle:PersonalAgenda', $id);
-                $eventInvitation = $event->getInvitation();
+            if ($personalEvent) {
+                $eventInvitation = $personalEvent->getInvitation();
+                $allowInvitees = !$eventInvitation instanceof AgendaEventSubscription;
 
-                if ($eventInvitation) {
+                if ($eventInvitation && $allowInvitees) {
                     foreach ($eventInvitation->getInvitees() as $invitee) {
                         $inviteeUser = $invitee->getUser();
 
@@ -2911,26 +3104,29 @@ class Agenda
                     }
                 }
 
-                $isCollective = $event->isCollective();
+                $isCollective = $personalEvent->isCollective();
             }
 
-            $form->addSelectAjax(
-                'invitees',
-                get_lang('Invitees'),
-                $invitees,
-                [
-                    'multiple' => 'multiple',
-                    'url' => api_get_path(WEB_AJAX_PATH).'message.ajax.php?a=find_users',
-                ]
-            );
-            $form->addCheckBox('collective', '', get_lang('IsItEditableByTheInvitees'));
+            if ($allowInvitees) {
+                $form->addSelectAjax(
+                    'invitees',
+                    get_lang('Invitees'),
+                    $invitees,
+                    [
+                        'multiple' => 'multiple',
+                        'url' => api_get_path(WEB_AJAX_PATH).'message.ajax.php?a=find_users',
+                    ]
+                );
+                $form->addCheckBox('collective', '', get_lang('IsItEditableByTheInvitees'));
+                $form->addHtml('<hr>');
 
-            $params['invitees'] = array_keys($invitees);
-            $params['collective'] = $isCollective;
+                $params['invitees'] = array_keys($invitees);
+                $params['collective'] = $isCollective;
+            }
         }
 
         if (api_get_configuration_value('agenda_reminders')) {
-            $form->addHtml('<hr><div id="notification_list">');
+            $form->addHtml('<div id="notification_list">');
 
             if ($id) {
                 $this->addFieldsForRemindersToForm($id, $form);
@@ -2941,6 +3137,83 @@ class Agenda
             $form->addHtml('<hr>');
         }
 
+        if (api_is_platform_admin()
+            && true === api_get_configuration_value('agenda_event_subscriptions')
+        ) {
+            $form->addHtml('<hr>');
+            $form->addSelect(
+                'subscription_visibility',
+                get_lang('AllowSubscriptions'),
+                [
+                    AgendaEventSubscription::SUBSCRIPTION_NO => get_lang('No'),
+                    AgendaEventSubscription::SUBSCRIPTION_ALL => get_lang('AllUsersOfThePlatform'),
+                    AgendaEventSubscription::SUBSCRIPTION_CLASS => get_lang('UsersInsideClass'),
+                ]
+            );
+            $slctItem = $form->addSelectAjax(
+                'subscription_item',
+                get_lang('SocialGroup').' / '.get_lang('Class'),
+                [],
+                [
+                    'url' => api_get_path(WEB_AJAX_PATH).'usergroup.ajax.php?a=get_class_by_keyword',
+                    'disabled' => 'disabled',
+                ]
+            );
+
+            $form->addNumeric(
+                'max_subscriptions',
+                ['', get_lang('MaxSubscriptionsLeaveEmptyToNotLimit')],
+                [
+                    'disabled' => 'disabled',
+                    'step' => 1,
+                    'min' => 0,
+                    'value' => 0,
+                ]
+            );
+            $form->addHtml("<script>
+                $(function () {
+                    $('#add_event_subscription_visibility')
+                        .on('change', function () {
+                            $('#max_subscriptions').prop('disabled', this.value == 0);
+                            $('#add_event_subscription_item').prop('disabled', this.value != 2);                        
+                        })
+                        .trigger('change');
+                })
+                </script>
+            ");
+
+            if ($personalEvent) {
+                $subscribers = self::getInviteesForPersonalEvent($personalEvent->getId(), AgendaEventSubscriber::class);
+                $subscribers = array_combine(
+                    array_column($subscribers, 'id'),
+                    array_column($subscribers, 'name')
+                );
+
+                $params['subscribers'] = array_keys($subscribers);
+
+                $form->addSelect(
+                    'subscribers',
+                    get_lang('Subscribers'),
+                    $subscribers,
+                    ['multiple' => 'multiple']
+                );
+
+                /** @var AgendaEventSubscription $subscription */
+                $subscription = $personalEvent->getInvitation();
+                $params['max_subscriptions'] = $subscription->getMaxAttendees();
+
+                $groupId = $personalEvent->getSubscriptionItemId();
+
+                if ($groupId) {
+                    $objUserGroup = new UserGroup();
+
+                    $groupInfo = $objUserGroup->get($groupId);
+
+                    $slctItem->addOption($groupInfo['name'], $groupId);
+                }
+            }
+        }
+
         if (api_get_configuration_value('allow_careers_in_global_agenda') && 'admin' === $this->type) {
             Career::addCareerFieldsToForm($form);
             $form->addHtml('<hr>');
@@ -4589,10 +4862,15 @@ class Agenda
      */
     public function formatEventDate($utcTime)
     {
-        $utcTimeZone = new DateTimeZone('UTC');
+        if ($utcTime instanceof DateTime) {
+            $eventDate = $utcTime;
+        } else {
+            $utcTimeZone = new DateTimeZone('UTC');
+            $eventDate = new DateTime($utcTime, $utcTimeZone);
+        }
+
         $platformTimeZone = new DateTimeZone(api_get_timezone());
 
-        $eventDate = new DateTime($utcTime, $utcTimeZone);
         $eventDate->setTimezone($platformTimeZone);
 
         return $eventDate->format(DateTime::ISO8601);
@@ -4609,24 +4887,33 @@ class Agenda
 
         $event = $em->find('ChamiloCoreBundle:PersonalAgenda', $eventId);
 
-        $invitation = new AgendaEventInvitation();
-        $invitation->setCreator(api_get_user_entity(api_get_user_id()));
+        $invitation = $event->getInvitation();
 
-        $event
-            ->setCollective($isCollective)
-            ->setInvitation($invitation)
-        ;
+        if ($invitation instanceof AgendaEventSubscription) {
+            return;
+        }
 
-        $em->persist($event);
+        if (!$invitation) {
+            $invitation = new AgendaEventInvitation();
+            $invitation->setCreator(api_get_user_entity(api_get_user_id()));
+
+            $event->setInvitation($invitation);
+        }
+
+        $event->setCollective($isCollective);
 
         foreach ($inviteeUserList as $inviteeId) {
-            $invitee = new AgendaEventInvitee();
-            $invitee
-                ->setUser(api_get_user_entity($inviteeId))
-                ->setInvitation($invitation)
-            ;
+            $userInvitee = api_get_user_entity($inviteeId);
 
-            $em->persist($invitee);
+            if (!$invitation->hasUserAsInvitee($userInvitee)) {
+                $invitee = new AgendaEventInvitee();
+                $invitee
+                    ->setUser($userInvitee)
+                    ->setInvitation($invitation)
+                ;
+
+                $em->persist($invitee);
+            }
         }
 
         $em->flush();

main/inc/lib/formvalidator/Element/SelectAjax.php

@@ -23,6 +23,8 @@ class SelectAjax extends HTML_QuickForm_select
     public function toHtml()
     {
         $iso = api_get_language_isocode(api_get_interface_language());
+        $dropdownParent = $this->getAttribute('dropdownParent');
+        $dropdownParentCondition = $dropdownParent ? "dropdownParent: '$dropdownParent'," : '';
         $formatResult = $this->getAttribute('formatResult');
         $formatSelection = $this->getAttribute('formatSelection');
         $formatCondition = '';
@@ -93,6 +95,7 @@ class SelectAjax extends HTML_QuickForm_select
                         width: '$width',
                         minimumInputLength: '$minimumInputLength',
                         tags: $tags,
+                        $dropdownParentCondition
                         ajax: {
                             url: $url,
                             delay: $delay,
@@ -130,6 +133,7 @@ JS;
         $this->removeAttribute('class');
         $this->removeAttribute('url');
         $this->removeAttribute('url_function');
+        $this->removeAttribute('dropdownParent');
         $this->setAttribute('style', 'width: 100%;');
 
         return parent::toHtml().$html;

main/inc/lib/template.lib.php

@@ -200,6 +200,7 @@ class Template
         $functions = [
             ['name' => 'get_tutors_names', 'callable' => 'Template::returnTutorsNames'],
             ['name' => 'get_teachers_names', 'callable' => 'Template::returnTeachersNames'],
+            ['name' => 'api_is_platform_admin', 'callable' => 'api_is_platform_admin'],
         ];
 
         foreach ($functions as $function) {

main/install/configuration.dist.php

@@ -462,6 +462,24 @@ CREATE UNIQUE INDEX UNIQ_D8612460AF68C6B ON personal_agenda (agenda_event_invita
 // Then add the "@" symbol to AgendaEventInvitation and AgendaEventInvitee classes in the ORM\Entity() line.
 // Then uncomment the "use EventCollectiveTrait;" line in the PersonalAgenda class.
 //$_configuration['agenda_collective_invitations'] = false;
+
+// It allows to other users to subscribe for events.
+// Requires enable agenda_collective_invitations before.
+// Requires DB changes:
+/*
+ALTER TABLE personal_agenda ADD subscription_visibility INT DEFAULT 0 NOT NULL, ADD subscription_item_id INT DEFAULT NULL;
+ALTER TABLE agenda_event_invitee ADD type VARCHAR(255) NOT NULL;
+ALTER TABLE agenda_event_invitation ADD type VARCHAR(255) NOT NULL, ADD max_attendees INT DEFAULT 0;
+UPDATE agenda_event_invitation SET type = 'invitation';
+UPDATE agenda_event_invitee SET type = 'invitee';
+*/
+// Then uncomment the "use EventSubscribableTrait;" line in the PersonalAgenda class.
+// Then add the "@" symbol in ORM\InheritanceType, ORM\DiscriminatorColumn and ORM\DiscriminatorMap lines in the AgendaEventInvitation class.
+// Then add the "@" symbol in @ORM\Entity line in the AgendaEventSubscription class.
+// Then add the "@" symbol in ORM\InheritanceType, ORM\DiscriminatorColumn and ORM\DiscriminatorMap lines in the AgendaEventInvitee class.
+// Then add the "@" symbol in @ORM\Entity line in the AgendaEventSubscriber class.
+//$_configuration['agenda_event_subscriptions'] = false;
+
 // Enable reminders for agenda events. Requires database changes:
 /*
  CREATE TABLE agenda_reminder (id BIGINT AUTO_INCREMENT NOT NULL, type VARCHAR(255) NOT NULL, event_id INT NOT NULL, date_interval VARCHAR(255) NOT NULL COMMENT '(DC2Type:dateinterval)', sent TINYINT(1) NOT NULL, created_at DATETIME NOT NULL, updated_at DATETIME NOT NULL, PRIMARY KEY(id)) DEFAULT CHARACTER SET utf8 COLLATE `utf8_unicode_ci` ENGINE = InnoDB;

main/template/default/agenda/month.tpl

@@ -1,4 +1,5 @@
 {% set agenda_collective_invitations = 'agenda_collective_invitations'|api_get_configuration_value %}
+{% set agenda_event_subscriptions = 'agenda_event_subscriptions'|api_get_configuration_value %}
 {% set agenda_reminders = 'agenda_reminders'|api_get_configuration_value %}
 {% set career_in_global_events = 'allow_careers_in_global_agenda'|api_get_configuration_value %}
 
@@ -340,6 +341,15 @@ $(function() {
                 //Reset the CKEditor content that persist in memory
                 CKEDITOR.instances['content'].setData('');
 				allFields.removeClass("ui-state-error");
+
+                $('#add_event_form').get(0).reset();
+
+                {% if agenda_event_subscriptions and 'personal' == type and api_is_platform_admin() %}
+                    $('#form_subscription_visibility').trigger('change').selectpicker('refresh');
+                    $('#form_subscriptions_container').show('');
+                    $('#form_subscriptions_edit').hide().html('');
+                {% endif %}
+
 				$("#dialog-form").dialog("open");
 				$("#dialog-form").dialog({
 					buttons: {
@@ -582,6 +592,13 @@ $(function() {
                     }
                 {% endif %}
 
+                {% if agenda_event_subscriptions and 'personal' == type and api_is_platform_admin() %}
+                    $('#form_subscriptions_container').hide();
+                    $('#form_subscriptions_edit')
+                        .html(showSubcriptionsContainer(calEvent))
+                        .show();
+                {% endif %}
+
                 {% if agenda_reminders %}
                     $('#notification_list').html('').next('.form-group').hide();
 
@@ -651,7 +668,7 @@ $(function() {
                 {% if career_in_global_events %}
                     var $careerFieldParent = $('#career_id').parents('.col-sm-8');
                     var $promotionFieldParent = $('#promotion_id').parents('.col-sm-8');
-                    
+
                     if ($careerFieldParent.find('#form_career_id_edit').length === 0) {
                         $careerFieldParent.append('<p id="form_career_id_edit" class="form-control-static"></p>');
                     }
@@ -941,19 +958,51 @@ $(function() {
                 };
 
                 {% if agenda_collective_invitations and 'personal' == type %}
-                    buttons['{{ "Delete"|get_lang }}'] = function () {
-                        $.ajax({
-                            url: delete_url,
-                            success:function() {
-                                calendar.fullCalendar('removeEvents',
-                                    calEvent
-                                );
-                                calendar.fullCalendar('refetchEvents');
-                                calendar.fullCalendar('rerenderEvents');
-                                $("#simple-dialog-form").dialog('close');
+                    if (!calEvent.subscription_visibility) {
+                        buttons['{{ "Delete"|get_lang }}'] = function () {
+                            $.ajax({
+                                url: delete_url,
+                                success:function() {
+                                    calendar.fullCalendar('removeEvents',
+                                        calEvent
+                                    );
+                                    calendar.fullCalendar('refetchEvents');
+                                    calendar.fullCalendar('rerenderEvents');
+                                    $("#simple-dialog-form").dialog('close');
+                                }
+                            });
+                        };
+                    }
+                {% endif %}
+
+                {% if agenda_event_subscriptions and 'personal' == type %}
+                    $('#simple_subscriptions').html(showSubcriptionsContainer(calEvent));
+
+                    if (calEvent.subscription_visibility > 0) {
+                        if (calEvent.user_is_subscribed) {
+                            buttons["{{ 'Unsubscribe'|get_lang }}"] = function () {
+                                $.ajax({
+                                    url: '{{ web_agenda_ajax_url }}&a=event_unsubscribe&id=' + calEvent.id,
+                                    success:function() {
+                                        calendar.fullCalendar('refetchEvents');
+                                        //calendar.fullCalendar('rerenderEvents');
+                                        $("#simple-dialog-form").dialog('close');
+                                    }
+                                });
+                            };
+                        } else if (calEvent.can_subscribe) {
+                            buttons["{{ 'Subscribe'|get_lang }}"] = function () {
+                                $.ajax({
+                                    url: '{{ web_agenda_ajax_url }}&a=event_subscribe&id=' + calEvent.id,
+                                    success:function() {
+                                        calendar.fullCalendar('refetchEvents');
+                                        //calendar.fullCalendar('rerenderEvents');
+                                        $("#simple-dialog-form").dialog('close');
+                                    }
+                                });
                             }
-                        });
-                    };
+                        }
+                    }
                 {% endif %}
 
                 if ('session_subscription' === calEvent.type) {
@@ -1004,6 +1053,48 @@ $(function() {
 	});
 
     {{ agenda_reminders_js }}
+
+    function showSubcriptionsContainer (calEvent) {
+        if ((calEvent.invitees && calEvent.invitees.length)
+            || !calEvent.subscription_visibility
+        ) {
+            return '';
+        }
+
+        var html = '';
+        html += '<dl class="dl-horizontal">';
+        html += "<dt>{{ 'AllowSubscriptions'|get_lang }}</dt>";
+        html += '<dd>';
+
+        if (1 === calEvent.subscription_visibility) {
+            html += "{{ 'AllUsersOfThePlatform'|get_lang }}";
+        }
+
+        if (2 === calEvent.subscription_visibility) {
+            html += "{{ 'UsersInsideClass'|get_lang }}<br>" + calEvent.usergroup;
+        }
+
+        html += '</dd>';
+
+        if (calEvent.max_subscriptions) {
+            html += "<dt>{{ 'MaxSubscriptions'|get_lang }}</dt>";
+            html += '<dd>' + calEvent.max_subscriptions + '</dd>';
+        }
+
+        html += "<dt>{{ 'Subscriptions'|get_lang }}</dt><dd>" + calEvent.count_subscribers + "</dd>";
+
+        if (calEvent.subscribers) {
+            html += '<dt>{{ 'Subscribers'|get_lang }}</dt><dd>';
+            html += calEvent.subscribers
+                .map(function (invitee) { return invitee.name; })
+                .join('<br>');
+            html += '</dd>'
+        }
+
+        html += '</dl>';
+
+        return html;
+    }
 });
 </script>
 {{ actions_div }}
@@ -1090,6 +1181,10 @@ $(function() {
                 </div>
             </div>
         {% endif %}
+
+        {% if agenda_event_subscriptions and 'personal' == type %}
+            <div class="form-group" id="simple_subscriptions"></div>
+        {% endif %}
     </form>
 </div>
 

src/Chamilo/CoreBundle/Entity/AgendaEventInvitation.php

@@ -14,6 +14,12 @@ use Doctrine\ORM\Mapping as ORM;
  * @ORM\Table(name="agenda_event_invitation")
  * Add @ to the next lineactivating the agenda_collective_invitations configuration setting.
  * ORM\Entity()
+ * ORM\InheritanceType("SINGLE_TABLE")
+ * ORM\DiscriminatorColumn(name="type", type="string")
+ * ORM\DiscriminatorMap({
+ *     "invitation" = "Chamilo\CoreBundle\Entity\AgendaEventInvitation",
+ *     "subscription" = "Chamilo\CoreBundle\Entity\AgendaEventSubscription"
+ * })
  */
 class AgendaEventInvitation
 {
@@ -91,15 +97,49 @@ class AgendaEventInvitation
         return $this;
     }
 
+    public function removeInvitees(): self
+    {
+        $this->invitees = new ArrayCollection();
+
+        return $this;
+    }
+
     public function getCreator(): User
     {
         return $this->creator;
     }
 
-    public function setCreator(User $creator): AgendaEventInvitation
+    public function setCreator(User $creator): self
     {
         $this->creator = $creator;
 
         return $this;
     }
+
+    public function hasUserAsInvitee(User $user): bool
+    {
+        return $this->invitees->exists(
+            function (int $key, AgendaEventInvitee $invitee) use ($user) {
+                return $invitee->getUser() === $user;
+            }
+        );
+    }
+
+    public function removeInviteesNotInIdList(array $idList): self
+    {
+        $toRemove = [];
+
+        /** @var AgendaEventInvitee $invitee */
+        foreach ($this->invitees as $key => $invitee) {
+            if (!in_array($invitee->getUser()->getId(), $idList)) {
+                $toRemove[] = $key;
+            }
+        }
+
+        foreach ($toRemove as $key) {
+            $this->invitees->remove($key);
+        }
+
+        return $this;
+    }
 }

src/Chamilo/CoreBundle/Entity/AgendaEventInvitee.php

@@ -12,6 +12,12 @@ use Doctrine\ORM\Mapping as ORM;
  * @ORM\Table(name="agenda_event_invitee")
  * Add @ to the next lineactivating the agenda_collective_invitations configuration setting.
  * ORM\Entity()
+ * ORM\InheritanceType("SINGLE_TABLE")
+ * ORM\DiscriminatorColumn(name="type", type="string")
+ * ORM\DiscriminatorMap({
+ *     "invitee" = "Chamilo\CoreBundle\Entity\AgendaEventInvitee",
+ *     "subscriber" = "Chamilo\CoreBundle\Entity\AgendaEventSubscriber"
+ * })
  */
 class AgendaEventInvitee
 {

src/Chamilo/CoreBundle/Entity/AgendaEventSubscriber.php

@@ -0,0 +1,14 @@
+<?php
+
+/* For licensing terms, see /license.txt */
+
+namespace Chamilo\CoreBundle\Entity;
+
+use Doctrine\ORM\Mapping as ORM;
+
+/**
+ * ORM\Entity()
+ */
+class AgendaEventSubscriber extends AgendaEventInvitee
+{
+}

src/Chamilo/CoreBundle/Entity/AgendaEventSubscription.php

@@ -0,0 +1,36 @@
+<?php
+
+/* For licensing terms, see /license.txt */
+
+namespace Chamilo\CoreBundle\Entity;
+
+use Doctrine\ORM\Mapping as ORM;
+
+/**
+ * ORM\Entity()
+ */
+class AgendaEventSubscription extends AgendaEventInvitation
+{
+    public const SUBSCRIPTION_NO = 0;
+    public const SUBSCRIPTION_ALL = 1;
+    public const SUBSCRIPTION_CLASS = 2;
+
+    /**
+     * @var int
+     *
+     * @ORM\Column(name="max_attendees", type="integer", nullable=false, options={"default": 0})
+     */
+    protected $maxAttendees = 0;
+
+    public function getMaxAttendees(): int
+    {
+        return $this->maxAttendees;
+    }
+
+    public function setMaxAttendees(int $maxAttendees): self
+    {
+        $this->maxAttendees = $maxAttendees;
+
+        return $this;
+    }
+}

src/Chamilo/CoreBundle/Entity/PersonalAgenda.php

@@ -4,6 +4,7 @@
 namespace Chamilo\CoreBundle\Entity;
 
 use Chamilo\CoreBundle\Traits\EventCollectiveTrait;
+use Chamilo\CoreBundle\Traits\EventSubscribableTrait;
 use Doctrine\ORM\Mapping as ORM;
 
 /**
@@ -17,6 +18,8 @@ class PersonalAgenda
 {
     // Uncomment next line when activating the agenda_collective_invitations configuration setting.
     //use EventCollectiveTrait;
+    // Uncomment next line when activating the agenda_event_subscriptions configuration setting.
+    //use EventSubscribableTrait;
 
     /**
      * @var int

src/Chamilo/CoreBundle/Entity/Repository/PersonalAgendaRepository.php

@@ -4,6 +4,7 @@
 
 namespace Chamilo\CoreBundle\Entity\Repository;
 
+use Chamilo\CoreBundle\Entity\AgendaEventSubscription;
 use Chamilo\CoreBundle\Entity\PersonalAgenda;
 use Chamilo\UserBundle\Entity\User;
 use Doctrine\ORM\EntityRepository;
@@ -25,6 +26,16 @@ class PersonalAgendaRepository extends EntityRepository
             )
         ;
 
+        if (api_get_configuration_value('agenda_event_subscriptions')) {
+            $qb
+                ->andWhere(
+                    $qb->expr()->not(
+                        $qb->expr()->isInstanceOf('i', AgendaEventSubscription::class)
+                    )
+                )
+            ;
+        }
+
         $params = [
             'user' => $user,
         ];

src/Chamilo/CoreBundle/Traits/EventSubscribableTrait.php

@@ -0,0 +1,48 @@
+<?php
+
+/* For licensing terms, see /license.txt */
+
+namespace Chamilo\CoreBundle\Traits;
+
+use Doctrine\ORM\Mapping as ORM;
+
+trait EventSubscribableTrait
+{
+    /**
+     * @var int
+     *
+     * @ORM\Column(name="subscription_visibility", type="integer", options={"default": 0})
+     */
+    protected $subscriptionVisibility = 0;
+
+    /**
+     * @var int
+     *
+     * @ORM\Column(name="subscription_item_id", type="integer", nullable=true)
+     */
+    protected $subscriptionItemId = null;
+
+    public function getSubscriptionVisibility(): int
+    {
+        return $this->subscriptionVisibility;
+    }
+
+    public function setSubscriptionVisibility(int $subscriptionVisibility): self
+    {
+        $this->subscriptionVisibility = $subscriptionVisibility;
+
+        return $this;
+    }
+
+    public function getSubscriptionItemId(): ?int
+    {
+        return $this->subscriptionItemId;
+    }
+
+    public function setSubscriptionItemId(?int $subscriptionItemId): self
+    {
+        $this->subscriptionItemId = $subscriptionItemId;
+
+        return $this;
+    }
+}