feat(public): add Open Graph metadata for public share links

lib/Controller/PublicViewController.php

@@ -8,15 +8,20 @@
 
 namespace OCA\Calendar\Controller;
 
+use OCA\DAV\CalDAV\CalDavBackend;
 use OCP\AppFramework\Controller;
 use OCP\AppFramework\Http\ContentSecurityPolicy;
 use OCP\AppFramework\Http\RedirectResponse;
 use OCP\AppFramework\Http\Response;
 use OCP\AppFramework\Http\Template\PublicTemplateResponse;
+use OCP\Defaults;
 use OCP\IConfig;
 use OCP\IInitialStateService;
+use OCP\IL10N;
 use OCP\IRequest;
 use OCP\IURLGenerator;
+use OCP\Util;
+use Sabre\DAV\Exception\NotFound;
 
 /**
  * Class PublicViewController
@@ -31,13 +36,19 @@ class PublicViewController extends Controller {
 	 * @param IConfig $config
 	 * @param IInitialStateService $initialStateService
 	 * @param IURLGenerator $urlGenerator
+	 * @param IL10N $l10n
+	 * @param Defaults $defaults
+	 * @param CalDavBackend $calDavBackend
 	 */
 	public function __construct(
 		string $appName,
 		IRequest $request,
 		private IConfig $config,
 		private IInitialStateService $initialStateService,
 		private IURLGenerator $urlGenerator,
+		private IL10N $l10n,
+		private Defaults $defaults,
+		private CalDavBackend $calDavBackend,
 	) {
 		parent::__construct($appName, $request);
 	}
@@ -110,10 +121,116 @@ private function publicIndex(string $token):PublicTemplateResponse {
 		$this->initialStateService->provideInitialState($this->appName, 'can_subscribe_link', $defaultCanSubscribeLink);
 		$this->initialStateService->provideInitialState($this->appName, 'show_resources', false);
 
-		return new PublicTemplateResponse($this->appName, 'main', [
-			'share_url' => $this->getShareURL(),
-			'preview_image' => $this->getPreviewImage(),
+		$shareUrl = $this->getShareURL();
+		$previewImage = $this->getPreviewImage();
+
+		$response = new PublicTemplateResponse($this->appName, 'main', [
+			'share_url' => $shareUrl,
+			'preview_image' => $previewImage,
 		]);
+
+		[$title, $description, $sharedBy] = $this->resolvePublicShareMeta($token);
+		$response->setHeaderTitle($title);
+		if ($sharedBy !== null) {
+			$response->setHeaderDetails($sharedBy);
+		}
+		$this->addOpenGraphHeaders($title, $description, $shareUrl, $previewImage);
+
+		return $response;
+	}
+
+	/**
+	 * Resolve calendar display name and owner for Open Graph / public header.
+	 *
+	 * @return array{0: string, 1: string, 2: ?string} title, description, shared-by details
+	 */
+	private function resolvePublicShareMeta(string $token): array {
+		$fallbackTitle = $this->l10n->t('Calendar');
+		$fallbackDescription = $this->l10n->t('A publicly shared calendar');
+
+		if ($token === '') {
+			return [$fallbackTitle, $fallbackDescription, null];
+		}
+
+		try {
+			$calendarInfo = $this->calDavBackend->getPublicCalendar($token);
+		} catch (NotFound) {
+			return [$fallbackTitle, $fallbackDescription, null];
+		}
+
+		$calendarName = $this->extractPublicCalendarDisplayName($calendarInfo);
+		$ownerDisplayName = $calendarInfo['{http://nextcloud.com/ns}owner-displayname'] ?? null;
+		if (!is_string($ownerDisplayName) || $ownerDisplayName === '') {
+			$ownerDisplayName = null;
+		}
+
+		if ($calendarName === null) {
+			return [$fallbackTitle, $fallbackDescription, $ownerDisplayName !== null
+				? $this->l10n->t('Shared by %s', [$ownerDisplayName])
+				: null];
+		}
+
+		$title = $calendarName;
+		if ($ownerDisplayName !== null) {
+			$description = $this->l10n->t('%s is a publicly shared calendar by %s', [$calendarName, $ownerDisplayName]);
+			$sharedBy = $this->l10n->t('Shared by %s', [$ownerDisplayName]);
+		} else {
+			$description = $this->l10n->t('%s is a publicly shared calendar', [$calendarName]);
+			$sharedBy = null;
+		}
+
+		return [$title, $description, $sharedBy];
+	}
+
+	/**
+	 * @param array<string, mixed> $calendarInfo
+	 */
+	private function extractPublicCalendarDisplayName(array $calendarInfo): ?string {
+		$displayName = $calendarInfo['{DAV:}displayname'] ?? null;
+		if (!is_string($displayName) || $displayName === '') {
+			return null;
+		}
+
+		// getPublicCalendar() appends " (uid)" to the display name for DAV clients.
+		$principalUri = $calendarInfo['principaluri'] ?? '';
+		if (is_string($principalUri) && $principalUri !== '') {
+			$uid = basename($principalUri);
+			if ($uid !== '') {
+				$suffix = ' (' . $uid . ')';
+				if (str_ends_with($displayName, $suffix)) {
+					$displayName = substr($displayName, 0, -strlen($suffix));
+				}
+			}
+		}
+
+		$displayName = trim($displayName);
+		return $displayName !== '' ? $displayName : null;
+	}
+
+	/**
+	 * Add Open Graph / Twitter meta tags so crawlers see title and description without JS.
+	 */
+	private function addOpenGraphHeaders(
+		string $title,
+		string $description,
+		string $shareUrl,
+		string $previewImage,
+	): void {
+		$siteName = $this->defaults->getName();
+
+		// Open Graph: https://ogp.me/
+		Util::addHeader('meta', ['property' => 'og:title', 'content' => $title]);
+		Util::addHeader('meta', ['property' => 'og:description', 'content' => $description]);
+		Util::addHeader('meta', ['property' => 'og:site_name', 'content' => $siteName]);
+		Util::addHeader('meta', ['property' => 'og:url', 'content' => $shareUrl]);
+		Util::addHeader('meta', ['property' => 'og:type', 'content' => 'website']);
+		Util::addHeader('meta', ['property' => 'og:image', 'content' => $previewImage]);
+
+		// Twitter / X cards
+		Util::addHeader('meta', ['property' => 'twitter:title', 'content' => $title]);
+		Util::addHeader('meta', ['property' => 'twitter:description', 'content' => $description]);
+		Util::addHeader('meta', ['property' => 'twitter:card', 'content' => 'summary']);
+		Util::addHeader('meta', ['property' => 'twitter:image', 'content' => $previewImage]);
 	}
 
 	/**

psalm.xml

@@ -37,11 +37,13 @@
 				<referencedClass name="OCA\Circles\Api\v1\Circles" />
 				<referencedClass name="OCA\Circles\Exceptions\CircleNotFoundException" />
 				<referencedClass name="OCA\Calendar\Controller\Exception" />
+				<referencedClass name="OCA\DAV\CalDAV\CalDavBackend" />
 				<referencedClass name="OCA\DAV\CalDAV\Calendar" />
 				<referencedClass name="OCA\DAV\CalDAV\CalendarHome" />
 				<referencedClass name="OCA\DAV\CalDAV\InvitationResponse\InvitationResponseServer" />
 				<referencedClass name="OCA\NotifyPush\Queue\IQueue" />
 				<referencedClass name="Psr\Http\Client\ClientExceptionInterface" />
+				<referencedClass name="Sabre\DAV\Exception\NotFound" />
 				<referencedClass name="Sabre\VObject\Component\VCalendar" />
 				<referencedClass name="Sabre\VObject\Component\VEvent" />
 				<referencedClass name="Sabre\VObject\Component\VTimezone" />

tests/php/unit/Controller/PublicViewControllerTest.php

@@ -9,13 +9,17 @@
 namespace OCA\Calendar\Controller;
 
 use ChristophWurst\Nextcloud\Testing\TestCase;
+use OCA\DAV\CalDAV\CalDavBackend;
 use OCP\AppFramework\Http\RedirectResponse;
 use OCP\AppFramework\Http\Template\PublicTemplateResponse;
+use OCP\Defaults;
 use OCP\IConfig;
 use OCP\IInitialStateService;
+use OCP\IL10N;
 use OCP\IRequest;
 use OCP\IURLGenerator;
 use PHPUnit\Framework\MockObject\MockObject;
+use Sabre\DAV\Exception\NotFound;
 
 class PublicViewControllerTest extends TestCase {
 	/** @var string */
@@ -33,7 +37,16 @@ class PublicViewControllerTest extends TestCase {
 	/** @var IURLGenerator|MockObject */
 	private $urlGenerator;
 
-	/** @var ViewController */
+	/** @var IL10N|MockObject */
+	private $l10n;
+
+	/** @var Defaults|MockObject */
+	private $defaults;
+
+	/** @var CalDavBackend|MockObject */
+	private $calDavBackend;
+
+	/** @var PublicViewController */
 	private $controller;
 
 	protected function setUp():void {
@@ -42,9 +55,22 @@ protected function setUp():void {
 		$this->config = $this->createMock(IConfig::class);
 		$this->initialStateService = $this->createMock(IInitialStateService::class);
 		$this->urlGenerator = $this->createMock(IURLGenerator::class);
+		$this->l10n = $this->createMock(IL10N::class);
+		$this->defaults = $this->createMock(Defaults::class);
+		$this->calDavBackend = $this->createMock(CalDavBackend::class);
+
+		$this->l10n->method('t')
+			->willReturnCallback(function (string $text, array $parameters = []) {
+				if ($parameters === []) {
+					return $text;
+				}
+				return vsprintf(str_replace('%s', '%s', $text), $parameters);
+			});
+		$this->defaults->method('getName')->willReturn('Nextcloud');
 
 		$this->controller = new PublicViewController($this->appName, $this->request,
-			$this->config, $this->initialStateService, $this->urlGenerator);
+			$this->config, $this->initialStateService, $this->urlGenerator,
+			$this->l10n, $this->defaults, $this->calDavBackend);
 	}
 
 	public function testPublicIndexWithBranding():void {
@@ -109,6 +135,7 @@ public function testPublicIndexWithBranding():void {
 				['calendar', 'show_resources', false],
 			]);
 
+		// Empty token → fallback meta (no CalDAV lookup)
 		$response = $this->controller->publicIndexWithBranding('');
 
 		$this->assertInstanceOf(PublicTemplateResponse::class, $response);
@@ -118,6 +145,65 @@ public function testPublicIndexWithBranding():void {
 		], $response->getParams());
 		$this->assertEquals('public', $response->getRenderAs());
 		$this->assertEquals('main', $response->getTemplateName());
+		$this->assertEquals('Calendar', $response->getHeaderTitle());
+		$this->assertEquals('', $response->getHeaderDetails());
+	}
+
+	public function testPublicIndexWithBrandingUsesCalendarMeta(): void {
+		$this->config->method('getAppValue')->willReturnMap([
+			['calendar', 'eventLimit', 'yes', 'yes'],
+			['calendar', 'currentView', 'dayGridMonth', 'dayGridMonth'],
+			['calendar', 'showWeekends', 'yes', 'yes'],
+			['calendar', 'showWeekNr', 'no', 'no'],
+			['calendar', 'skipPopover', 'yes', 'yes'],
+			['calendar', 'timezone', 'automatic', 'automatic'],
+			['calendar', 'slotDuration', '00:30:00', '00:30:00'],
+			['calendar', 'showTasks', 'yes', 'yes'],
+			['calendar', 'tasksSidebar', 'yes', 'yes'],
+			['dav', 'allow_calendar_link_subscriptions', 'yes', 'yes'],
+			['calendar', 'installed_version', '', '1.0.0'],
+		]);
+		$this->request->method('getServerProtocol')->willReturn('https');
+		$this->request->method('getServerHost')->willReturn('cloud.example');
+		$this->request->method('getRequestUri')->willReturn('/apps/calendar/p/token123');
+		$this->urlGenerator->method('imagePath')->willReturn('img');
+		$this->urlGenerator->method('getAbsoluteURL')->willReturn('https://cloud.example/img');
+
+		$this->request->method('getHeader')->with('Accept')->willReturn('text/html');
+		$this->calDavBackend->expects(self::once())
+			->method('getPublicCalendar')
+			->with('token123')
+			->willReturn([
+				'{DAV:}displayname' => 'Team events (alice)',
+				'principaluri' => 'principals/users/alice',
+				'{http://nextcloud.com/ns}owner-displayname' => 'Alice Wonder',
+			]);
+
+		$response = $this->controller->publicIndexWithBranding('token123');
+
+		$this->assertInstanceOf(PublicTemplateResponse::class, $response);
+		$this->assertEquals('Team events', $response->getHeaderTitle());
+		$this->assertEquals('Shared by Alice Wonder', $response->getHeaderDetails());
+	}
+
+	public function testPublicIndexWithBrandingFallsBackWhenCalendarMissing(): void {
+		$this->config->method('getAppValue')->willReturn('yes');
+		$this->request->method('getServerProtocol')->willReturn('https');
+		$this->request->method('getServerHost')->willReturn('cloud.example');
+		$this->request->method('getRequestUri')->willReturn('/apps/calendar/p/missing');
+		$this->urlGenerator->method('imagePath')->willReturn('img');
+		$this->urlGenerator->method('getAbsoluteURL')->willReturn('https://cloud.example/img');
+
+		$this->request->method('getHeader')->with('Accept')->willReturn('text/html');
+		$this->calDavBackend->expects(self::once())
+			->method('getPublicCalendar')
+			->with('missing')
+			->willThrowException(new NotFound());
+
+		$response = $this->controller->publicIndexWithBranding('missing');
+
+		$this->assertEquals('Calendar', $response->getHeaderTitle());
+		$this->assertEquals('', $response->getHeaderDetails());
 	}
 
 	public function testRedirectionIfRequestedWithAcceptCalendarHeader(): void {