SEO: event meta title with date, Open Graph defaults, cache invalidation

- event detail pages: <title> is "Title – 03.12.2026" (multi-day ranges
  supported) so recurring events with the same name stay distinguishable;
  H1 and lists keep the editor's title
- meta description fallback for events without teaser/description (date,
  time, location); a teaser that is only an insert tag (shared series
  text) also falls back, so a series does not share one description
- EventOpenGraphProvider for numero2/contao-opengraph3 (registered only
  when the bundle is installed, priority above its CalendarEventsProvider):
  og:title with date, og:description from teaser, event image as og:image
- FrontendCacheInvalidator: frontend event/organization edits write via
  DBAL, so invalidate the same cache tags the backend uses; tag the map
  and organization listing, invalidate the generic organization tag on
  backend saves

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

composer.json

@@ -29,5 +29,8 @@
       "contao-components/installer": true,
       "contao/manager-plugin": true
     }
+  },
+  "suggest": {
+    "numero2/contao-opengraph3": "Open-Graph-Standardwerte (Titel mit Datum, Teaser, Eventbild) für Event-Detailseiten"
   }
 }

config/services.yaml

@@ -9,6 +9,8 @@ services:
       - ../src/DependencyInjection/
       - ../src/Contao/Manager/
       - ../src/EventManagerBundle.php
+      - ../src/OpenGraph/            # nur mit numero2/contao-opengraph3, siehe EventManagerExtension
+      - ../src/Seo/                  # statische Helfer, kein Service
 
   Mummert\EventManagerBundle\EventListener\DataContainer\SetDateAddedCallback:
     tags:

contao/dca/tl_organization.php

@@ -305,3 +305,11 @@ $GLOBALS['TL_DCA']['tl_organization']['fields']['alias']['save_callback'][] = st
 
     return $value;
 };
+
+// Organisationsliste und Karte sind mit dem allgemeinen Tabellen-Tag getaggt
+// (FrontendCacheInvalidator): beim Speichern im Backend mit invalidieren.
+$GLOBALS['TL_DCA']['tl_organization']['config']['oninvalidate_cache_tags_callback'][] = static function ($dc, array $tags): array {
+    $tags[] = \Mummert\EventManagerBundle\Service\FrontendCacheInvalidator::ORGANIZATION_TAG;
+
+    return $tags;
+};

src/Controller/Frontend/EventMapController.php

@@ -29,11 +29,15 @@ class EventMapController extends AbstractFrontendModuleController
 
     public function __construct(
         private readonly MapModuleDataProvider $mapModuleDataProvider,
+        private readonly \Mummert\EventManagerBundle\Service\FrontendCacheInvalidator $cacheInvalidator,
     ) {
     }
 
     protected function getResponse(FragmentTemplate $template, ModuleModel $model, Request $request): Response
     {
+        // Karte zeigt Events aller Kalender und Organisationen: bei Änderungen neu erzeugen
+        $this->tagResponse($this->cacheInvalidator->getMapTags());
+
         $containerId = sprintf('eventmanager-map-%d', (int) ($model->id ?? 0));
         $dataElementId = sprintf('%s-data', $containerId);
         $filterWrapperId = sprintf('%s-filter', $containerId);

src/DependencyInjection/EventManagerExtension.php

@@ -4,6 +4,8 @@ declare(strict_types=1);
 
 namespace Mummert\EventManagerBundle\DependencyInjection;
 
+use Mummert\EventManagerBundle\OpenGraph\EventOpenGraphProvider;
+use numero2\Opengraph3Bundle\OpenGraph\Provider\ProviderInterface;
 use Symfony\Component\Config\FileLocator;
 use Symfony\Component\DependencyInjection\ContainerBuilder;
 use Symfony\Component\DependencyInjection\Extension\Extension;
@@ -15,5 +17,14 @@ class EventManagerExtension extends Extension
     {
         $loader = new YamlFileLoader($container, new FileLocator(__DIR__ . '/../../config'));
         $loader->load('services.yaml');
+
+        // Open-Graph-Standardwerte für Events, nur wenn numero2/contao-opengraph3 installiert ist.
+        // Höhere Priorität als dessen eigener CalendarEventsProvider (der erste passende Provider gewinnt).
+        if (interface_exists(ProviderInterface::class)) {
+            $container->register(EventOpenGraphProvider::class, EventOpenGraphProvider::class)
+                ->setAutowired(true)
+                ->setAutoconfigured(false)
+                ->addTag('numero2_opengraph3.provider', ['priority' => 10]);
+        }
     }
 }

src/EventListener/EventFullTemplateDataListener.php

@@ -5,10 +5,13 @@ declare(strict_types=1);
 namespace Mummert\EventManagerBundle\EventListener;
 
 use Contao\CoreBundle\DependencyInjection\Attribute\AsHook;
+use Contao\CoreBundle\Routing\ResponseContext\HtmlHeadBag\HtmlHeadBag;
+use Contao\CoreBundle\Routing\ResponseContext\ResponseContextAccessor;
 use Contao\StringUtil;
 use Contao\Template;
 use Doctrine\DBAL\Connection;
 use Doctrine\DBAL\ParameterType;
+use Mummert\EventManagerBundle\Seo\EventMetaTitle;
 
 #[AsHook('parseTemplate', method: 'onParseTemplate')]
 class EventFullTemplateDataListener
@@ -17,6 +20,7 @@ class EventFullTemplateDataListener
 
     public function __construct(
         private readonly Connection $connection,
+        private readonly ResponseContextAccessor $responseContextAccessor,
     ) {
     }
 
@@ -41,6 +45,9 @@ class EventFullTemplateDataListener
         $organizations = $this->fetchOrganizations($eventId);
         $tags = $this->fetchTags($eventId);
 
+        $this->setMetaTitle($data);
+        $this->setMetaDescriptionFallback($data, $locationRow);
+
         $template->location_row = $locationRow;
         $template->organizations = $organizations;
         $template->tags = $tags;
@@ -62,6 +69,75 @@ class EventFullTemplateDataListener
         $template->tag_fields = $this->toFlatTagFields($tags);
     }
 
+    /**
+     * Meta-Titel mit Datum ("Titel – 03.12.2026"), damit wiederkehrende Events
+     * gleichen Namens in den Suchergebnissen unterscheidbar sind. H1 und Listen
+     * zeigen weiterhin nur den Redaktions-Titel.
+     *
+     * @param array<string, mixed> $data
+     */
+    private function setMetaTitle(array $data): void
+    {
+        $headBag = $this->responseContextAccessor->getResponseContext()?->get(HtmlHeadBag::class);
+
+        if (!$headBag instanceof HtmlHeadBag) {
+            return;
+        }
+
+        $title = EventMetaTitle::build($data);
+
+        if ('' !== $title) {
+            $headBag->setTitle($title);
+        }
+    }
+
+    /**
+     * Ersatz-Description für Events ohne Teaser/Beschreibung (Redakteure pflegen
+     * keine Meta-Description): "Titel am 03.12.2026 um 16:30 Uhr in Ort, Stadt."
+     *
+     * @param array<string, mixed>  $data
+     * @param array<string, string> $locationRow
+     */
+    private function setMetaDescriptionFallback(array $data, array $locationRow): void
+    {
+        $headBag = $this->responseContextAccessor->getResponseContext()?->get(HtmlHeadBag::class);
+
+        if (!$headBag instanceof HtmlHeadBag) {
+            return;
+        }
+
+        // Vorhandene Description behalten, außer sie ist leer oder stammt aus einem Teaser,
+        // der nur aus einem Insert-Tag besteht (z. B. {{insert_content::ID}} als gemeinsamer
+        // Serien-Teaser: sonst hätten alle Events der Serie dieselbe Description).
+        $hasOwnDescription = '' !== trim(strip_tags((string) ($data['description'] ?? '')));
+        $teaserIsInsertTagOnly = (bool) preg_match('/^\{\{[^{}]+\}\}$/', trim((string) ($data['teaser'] ?? '')));
+
+        if ($hasOwnDescription || ('' !== trim($headBag->getMetaDescription()) && !$teaserIsInsertTagOnly)) {
+            return;
+        }
+
+        $title = html_entity_decode(strip_tags((string) ($data['title'] ?? '')), ENT_QUOTES | ENT_HTML5, 'UTF-8');
+        $date = EventMetaTitle::formatDate((int) ($data['startDate'] ?? 0), (int) ($data['endDate'] ?? 0));
+
+        if ('' === $date) {
+            return;
+        }
+
+        $description = trim($title).(str_contains($date, '–') ? ' vom '.str_replace('–', ' bis ', $date) : ' am '.$date);
+
+        if (!empty($data['addTime']) && !empty($data['startTime'])) {
+            $description .= ' um '.date('H:i', (int) $data['startTime']).' Uhr';
+        }
+
+        $place = implode(', ', array_filter([trim((string) ($locationRow['title'] ?? '')), trim((string) ($locationRow['city'] ?? ''))]));
+
+        if ('' !== $place) {
+            $description .= ' in '.$place;
+        }
+
+        $headBag->setMetaDescription($description.'. Termin und Infos im Veranstaltungskalender Nossener Land.');
+    }
+
     /** @return array<string, string> */
     private function fetchLocationRow(int $locationId): array
     {

src/EventListener/OrganizationListingTemplateDataListener.php

@@ -18,6 +18,7 @@ class OrganizationListingTemplateDataListener
     public function __construct(
         private readonly Connection $connection,
         private readonly ?LoggerInterface $logger = null,
+        private readonly \Mummert\EventManagerBundle\Service\FrontendCacheInvalidator $cacheInvalidator,
     ) {
     }
 
@@ -27,6 +28,9 @@ class OrganizationListingTemplateDataListener
             return;
         }
 
+        // Seite bei Änderungen an Organisationen automatisch aus dem Cache werfen
+        $this->cacheInvalidator->tagOrganizationListing();
+
         $tbody = $template->tbody;
 
         if (!\is_array($tbody) || [] === $tbody) {

src/OpenGraph/EventOpenGraphProvider.php

@@ -0,0 +1,125 @@
+<?php
+
+declare(strict_types=1);
+
+namespace Mummert\EventManagerBundle\OpenGraph;
+
+use Contao\CalendarEventsModel;
+use Contao\CoreBundle\InsertTag\InsertTagParser;
+use Contao\Input;
+use Contao\ModuleModel;
+use Contao\StringUtil;
+use Doctrine\DBAL\Connection;
+use Mummert\EventManagerBundle\Seo\EventMetaTitle;
+use numero2\Opengraph3Bundle\OpenGraph\OpenGraphReference;
+use numero2\Opengraph3Bundle\OpenGraph\Provider\ProviderInterface;
+
+/**
+ * Open-Graph-Standardwerte für Event-Detailseiten (numero2/contao-opengraph3).
+ *
+ * Redakteure pflegen keine OG-Felder. Ohne diesen Provider würden alle Events
+ * Titel und Bild der Website-Root teilen. Werte, die im Event selbst gepflegt
+ * sind (Reiter "OpenGraph"), haben weiterhin Vorrang.
+ *
+ * Wird nur registriert, wenn numero2/contao-opengraph3 installiert ist
+ * (siehe EventManagerExtension).
+ */
+class EventOpenGraphProvider implements ProviderInterface
+{
+    private const DESCRIPTION_LENGTH = 200;
+
+    public function __construct(
+        private readonly InsertTagParser $insertTagParser,
+        private readonly Connection $connection,
+    ) {
+    }
+
+    public function supports(ModuleModel $model): bool
+    {
+        return 'eventreader' === $model->type;
+    }
+
+    public function getReference(ModuleModel $model): ?OpenGraphReference
+    {
+        $event = CalendarEventsModel::findPublishedByParentAndIdOrAlias(
+            (string) Input::get('auto_item'),
+            StringUtil::deserialize($model->cal_calendar, true),
+        );
+
+        if (null === $event) {
+            return null;
+        }
+
+        $row = $event->row();
+        $defaults = [
+            'og_type' => 'website',
+            'og_title' => EventMetaTitle::build($row),
+            'og_description' => $this->buildDescription($row),
+        ];
+
+        if ($event->addImage && $event->singleSRC) {
+            $defaults['og_image'] = $event->singleSRC;
+        }
+
+        return new OpenGraphReference($event, $defaults);
+    }
+
+    /**
+     * @param array<string, mixed> $row
+     */
+    private function buildDescription(array $row): string
+    {
+        foreach (['teaser', 'description'] as $field) {
+            $text = $this->toPlainText((string) ($row[$field] ?? ''));
+
+            if ('' !== $text) {
+                return $this->truncate($text);
+            }
+        }
+
+        // Kein Text gepflegt: Datum, Uhrzeit und Ort als Beschreibung
+        $parts = [EventMetaTitle::formatDate((int) ($row['startDate'] ?? 0), (int) ($row['endDate'] ?? 0))];
+
+        if (!empty($row['addTime']) && !empty($row['startTime'])) {
+            $parts[0] .= ', '.date('H:i', (int) $row['startTime']).' Uhr';
+        }
+
+        $locationId = (int) ($row['location_id'] ?? 0);
+
+        if ($locationId > 0) {
+            $location = $this->connection->fetchAssociative('SELECT title, city FROM tl_location WHERE id = ?', [$locationId]);
+
+            if ($location) {
+                $parts[] = trim(implode(', ', array_filter([(string) $location['title'], (string) $location['city']])));
+            }
+        }
+
+        return implode(' – ', array_filter($parts));
+    }
+
+    private function toPlainText(string $value): string
+    {
+        // Leer oder nur ein Insert-Tag (gemeinsamer Serien-Teaser): lieber Datum und Ort
+        if ('' === trim($value) || preg_match('/^\{\{[^{}]+\}\}$/', trim($value))) {
+            return '';
+        }
+
+        $value = $this->insertTagParser->replaceInline($value);
+        $value = preg_replace('/<(br|\/p|\/li|\/h[1-6])\b[^>]*>/i', ' ', $value) ?? $value;
+        $value = html_entity_decode(strip_tags($value), ENT_QUOTES | ENT_HTML5, 'UTF-8');
+
+        return trim((string) preg_replace('/\s+/u', ' ', $value));
+    }
+
+    private function truncate(string $text): string
+    {
+        if (mb_strlen($text) <= self::DESCRIPTION_LENGTH) {
+            return $text;
+        }
+
+        $cut = mb_substr($text, 0, self::DESCRIPTION_LENGTH);
+        $space = mb_strrpos($cut, ' ');
+
+        return rtrim(false !== $space && $space > 120 ? mb_substr($cut, 0, $space) : $cut, " ,.;:–-").' …';
+    }
+}

src/Seo/EventMetaTitle.php

@@ -0,0 +1,60 @@
+<?php
+
+declare(strict_types=1);
+
+namespace Mummert\EventManagerBundle\Seo;
+
+/**
+ * Meta-Titel für Event-Detailseiten: Redaktions-Titel plus Datum, z. B.
+ * "Sterne falten – 03.12.2026" oder "Reiterferien – 03.08.–07.08.2027".
+ *
+ * Das Datum erscheint nur im <title> und in og:title, nicht in der H1 und nicht
+ * in den Listen. So bleiben wiederkehrende Veranstaltungen gleichen Namens
+ * für Suchmaschinen unterscheidbar.
+ */
+final class EventMetaTitle
+{
+    /**
+     * @param array<string, mixed> $event Event-Datensatz (title, pageTitle, startDate, endDate)
+     */
+    public static function build(array $event): string
+    {
+        $base = self::clean((string) ($event['pageTitle'] ?? ''));
+
+        if ('' === $base) {
+            $base = self::clean((string) ($event['title'] ?? ''));
+        }
+
+        $date = self::formatDate((int) ($event['startDate'] ?? 0), (int) ($event['endDate'] ?? 0));
+
+        if ('' === $date) {
+            return $base;
+        }
+
+        return '' === $base ? $date : $base.' – '.$date;
+    }
+
+    public static function formatDate(int $start, int $end = 0): string
+    {
+        if ($start <= 0) {
+            return '';
+        }
+
+        if ($end <= 0 || date('Ymd', $end) === date('Ymd', $start)) {
+            return date('d.m.Y', $start);
+        }
+
+        if (date('Y', $end) === date('Y', $start)) {
+            return date('d.m.', $start).'–'.date('d.m.Y', $end);
+        }
+
+        return date('d.m.Y', $start).'–'.date('d.m.Y', $end);
+    }
+
+    private static function clean(string $value): string
+    {
+        $value = html_entity_decode(strip_tags($value), ENT_QUOTES | ENT_HTML5, 'UTF-8');
+
+        return trim((string) preg_replace('/\s+/u', ' ', $value));
+    }
+}

src/Service/EventRepository.php

@@ -11,6 +11,7 @@ class EventRepository
 {
     public function __construct(
         private readonly Connection $connection,
+        private readonly FrontendCacheInvalidator $cacheInvalidator,
     ) {
     }
 
@@ -71,6 +72,8 @@ class EventRepository
             ['id' => $eventId],
             ['id' => ParameterType::INTEGER],
         );
+
+        $this->cacheInvalidator->invalidateEvent($eventId);
     }
 
     public function duplicate(int $eventId): ?int
@@ -138,6 +141,8 @@ class EventRepository
             $this->assignTagsToEvent($newEventId, $tagIds);
         }
 
+        $this->cacheInvalidator->invalidateEvent($newEventId);
+
         return $newEventId;
     }
 
@@ -264,6 +269,8 @@ class EventRepository
 
     public function delete(int $eventId): void
     {
+        $calendarId = (int) $this->connection->fetchOne('SELECT pid FROM tl_calendar_events WHERE id = ?', [$eventId]);
+
         $this->connection->delete(
             'tl_tags_rel',
             ['ptable' => 'tl_calendar_events', 'field' => 'tags', 'pid' => $eventId],
@@ -281,6 +288,8 @@ class EventRepository
             ['id' => $eventId],
             ['id' => ParameterType::INTEGER],
         );
+
+        $this->cacheInvalidator->invalidateEvent($eventId, $calendarId);
     }
 
     /** @return array<string, mixed>|null */
@@ -508,6 +517,8 @@ class EventRepository
                 ],
             );
         }
+
+        $this->cacheInvalidator->invalidateEvent($eventId);
     }
 
     /**
@@ -525,6 +536,8 @@ class EventRepository
                 'id' => ParameterType::INTEGER,
             ],
         );
+
+        $this->cacheInvalidator->invalidateEvent($eventId);
     }
 
     /**
@@ -573,6 +586,8 @@ class EventRepository
 
         $this->assignEventToOrganizations($eventId, $allowedOrganizationIds);
 
+        $this->cacheInvalidator->invalidateEvent($eventId);
+
         return $eventId;
     }
 
@@ -730,6 +745,8 @@ class EventRepository
             ['id' => $eventId],
             $types,
         );
+
+        $this->cacheInvalidator->invalidateEvent($eventId);
     }
 
     /** @return array<int> */

src/Service/FrontendCacheInvalidator.php

@@ -0,0 +1,67 @@
+<?php
+
+declare(strict_types=1);
+
+namespace Mummert\EventManagerBundle\Service;
+
+use Contao\CoreBundle\Cache\CacheTagManager;
+use Doctrine\DBAL\Connection;
+
+/**
+ * Leert den Contao-Seitencache nach Änderungen aus dem Frontend (Veranstalterbereich).
+ *
+ * Die Repositories schreiben direkt per DBAL. Anders als beim Speichern im Backend
+ * (DC_Table) bekommt Contao davon nichts mit, ohne Invalidierung wären Änderungen
+ * erst nach Ablauf der Cache-Zeit sichtbar.
+ *
+ * Tags wie im Backend: Event selbst + Kalender-Archiv (Listen, Kalender, Karte).
+ */
+class FrontendCacheInvalidator
+{
+    public const ORGANIZATION_TAG = 'contao.db.tl_organization';
+
+    public function __construct(
+        private readonly CacheTagManager $cacheTagManager,
+        private readonly Connection $connection,
+    ) {
+    }
+
+    public function invalidateEvent(int $eventId, ?int $calendarId = null): void
+    {
+        $tags = ['contao.db.tl_calendar_events.'.$eventId];
+
+        $calendarId ??= (int) $this->connection->fetchOne('SELECT pid FROM tl_calendar_events WHERE id = ?', [$eventId]);
+
+        if ($calendarId > 0) {
+            $tags[] = 'contao.db.tl_calendar.'.$calendarId;
+        }
+
+        $this->cacheTagManager->invalidateTags($tags);
+    }
+
+    public function invalidateOrganization(int $organizationId): void
+    {
+        $this->cacheTagManager->invalidateTags([self::ORGANIZATION_TAG, self::ORGANIZATION_TAG.'.'.$organizationId]);
+    }
+
+    /**
+     * Tags für Seiten, die Events aller Kalender und Organisationen zeigen (Karte).
+     *
+     * @return list<string>
+     */
+    public function getMapTags(): array
+    {
+        $tags = [self::ORGANIZATION_TAG];
+
+        foreach ($this->connection->fetchFirstColumn('SELECT id FROM tl_calendar') as $calendarId) {
+            $tags[] = 'contao.db.tl_calendar.'.$calendarId;
+        }
+
+        return $tags;
+    }
+
+    public function tagOrganizationListing(): void
+    {
+        $this->cacheTagManager->tagWith([self::ORGANIZATION_TAG]);
+    }
+}

src/Service/OrganizationRepository.php

@@ -11,6 +11,7 @@ class OrganizationRepository
 {
     public function __construct(
         private readonly Connection $connection,
+        private readonly FrontendCacheInvalidator $cacheInvalidator,
     ) {
     }
 
@@ -85,6 +86,8 @@ class OrganizationRepository
                 'id' => ParameterType::INTEGER,
             ],
         );
+
+        $this->cacheInvalidator->invalidateOrganization($organizationId);
     }
 
     public function updateLogo(int $organizationId, ?string $logoUuid): void
@@ -106,6 +109,8 @@ class OrganizationRepository
             ['id' => $organizationId],
             $types,
         );
+
+        $this->cacheInvalidator->invalidateOrganization($organizationId);
     }
 
     /**
@@ -208,6 +213,8 @@ class OrganizationRepository
                 ],
             );
         }
+
+        $this->cacheInvalidator->invalidateOrganization($organizationId);
     }
 
     /** @return array<int> */