feat(files_sharing): configure public share link base URL

apps/files_sharing/composer/composer/autoload_classmap.php

@@ -98,6 +98,7 @@
     'OCA\\Files_Sharing\\Notification\\Notifier' => $baseDir . '/../lib/Notification/Notifier.php',
     'OCA\\Files_Sharing\\OpenMetrics\\SharesCountMetric' => $baseDir . '/../lib/OpenMetrics/SharesCountMetric.php',
     'OCA\\Files_Sharing\\OrphanHelper' => $baseDir . '/../lib/OrphanHelper.php',
+    'OCA\\Files_Sharing\\PublicShareUrlGenerator' => $baseDir . '/../lib/PublicShareUrlGenerator.php',
     'OCA\\Files_Sharing\\Repair\\CleanupShareTarget' => $baseDir . '/../lib/Repair/CleanupShareTarget.php',
     'OCA\\Files_Sharing\\ResponseDefinitions' => $baseDir . '/../lib/ResponseDefinitions.php',
     'OCA\\Files_Sharing\\Scanner' => $baseDir . '/../lib/Scanner.php',

apps/files_sharing/composer/composer/autoload_static.php

@@ -113,6 +113,7 @@ class ComposerStaticInitFiles_Sharing
         'OCA\\Files_Sharing\\Notification\\Notifier' => __DIR__ . '/..' . '/../lib/Notification/Notifier.php',
         'OCA\\Files_Sharing\\OpenMetrics\\SharesCountMetric' => __DIR__ . '/..' . '/../lib/OpenMetrics/SharesCountMetric.php',
         'OCA\\Files_Sharing\\OrphanHelper' => __DIR__ . '/..' . '/../lib/OrphanHelper.php',
+        'OCA\\Files_Sharing\\PublicShareUrlGenerator' => __DIR__ . '/..' . '/../lib/PublicShareUrlGenerator.php',
         'OCA\\Files_Sharing\\Repair\\CleanupShareTarget' => __DIR__ . '/..' . '/../lib/Repair/CleanupShareTarget.php',
         'OCA\\Files_Sharing\\ResponseDefinitions' => __DIR__ . '/..' . '/../lib/ResponseDefinitions.php',
         'OCA\\Files_Sharing\\Scanner' => __DIR__ . '/..' . '/../lib/Scanner.php',

apps/files_sharing/lib/Controller/ShareAPIController.php

@@ -18,6 +18,7 @@
 use OCA\Federation\TrustedServers;
 use OCA\Files_Sharing\Exceptions\SharingRightsException;
 use OCA\Files_Sharing\External\Storage;
+use OCA\Files_Sharing\PublicShareUrlGenerator;
 use OCA\Files_Sharing\ResponseDefinitions;
 use OCA\Files_Sharing\SharedStorage;
 use OCA\GlobalSiteSelector\Service\SlaveService;
@@ -107,6 +108,7 @@ public function __construct(
 		private IMailer $mailer,
 		private ITagManager $tagManager,
 		private IEmailValidator $emailValidator,
+		private PublicShareUrlGenerator $publicShareUrlGenerator,
 		private ?TrustedServers $trustedServers,
 		private ?string $userId = null,
 	) {
@@ -271,7 +273,7 @@ protected function formatShare(IShare $share, ?Node $recipientNode = null): arra
 			$result['share_with'] = $share->getSharedWith();
 			$result['share_with_displayname'] = $group !== null ? $group->getDisplayName() : $share->getSharedWith();
 		} elseif ($share->getShareType() === IShare::TYPE_LINK) {
-			$url = $token ? $this->urlGenerator->linkToRouteAbsolute('files_sharing.sharecontroller.showShare', ['token' => $token]) : null;
+			$url = $token ? $this->publicShareUrlGenerator->getUrl($token) : null;
 
 			// "share_with" and "share_with_displayname" for passwords of link
 			// shares was deprecated in Nextcloud 15, use "password" instead.
@@ -293,6 +295,7 @@ protected function formatShare(IShare $share, ?Node $recipientNode = null): arra
 			$result['share_with_displayname'] = $this->getDisplayNameFromAddressBook($share->getSharedWith(), 'CLOUD');
 			$result['token'] = $token;
 		} elseif ($share->getShareType() === IShare::TYPE_EMAIL) {
+			$result['url'] = $token ? $this->publicShareUrlGenerator->getUrl($token) : null;
 			$result['share_with'] = $share->getSharedWith();
 			$result['password'] = $this->formatPasswordField($share->getPassword());
 			$result['password_expiration_time'] = $share->getPasswordExpirationTime() !== null ? $share->getPasswordExpirationTime()->format(\DateTime::ATOM) : null;

apps/files_sharing/lib/DefaultPublicShareTemplateProvider.php

@@ -45,6 +45,7 @@ public function __construct(
 		private IPreview $previewManager,
 		protected FederatedShareProvider $federatedShareProvider,
 		private IUrlGenerator $urlGenerator,
+		private PublicShareUrlGenerator $publicShareUrlGenerator,
 		private IEventDispatcher $eventDispatcher,
 		private IL10N $l10n,
 		private Defaults $defaults,
@@ -175,7 +176,7 @@ public function renderPage(IShare $share, string $token, string $path): Template
 			}
 		}
 
-		$shareUrl = $this->urlGenerator->linkToRouteAbsolute('files_sharing.sharecontroller.showShare', ['token' => $token]);
+		$shareUrl = $this->publicShareUrlGenerator->getUrl($token);
 		// By default use the share link as the direct link
 		$directLink = $shareUrl;
 		// Add the direct link header actions
@@ -199,7 +200,7 @@ public function renderPage(IShare $share, string $token, string $path): Template
 	protected function addMetaHeaders(IShare $share): void {
 		$shareNode = $share->getNode();
 		$token = $share->getToken();
-		$shareUrl = $this->urlGenerator->linkToRouteAbsolute('files_sharing.sharecontroller.showShare', ['token' => $token]);
+		$shareUrl = $this->publicShareUrlGenerator->getUrl($token);
 
 		// Handle preview generation for OpenGraph
 		$hasImagePreview = false;

apps/files_sharing/lib/PublicShareUrlGenerator.php

@@ -0,0 +1,75 @@
+<?php
+
+declare(strict_types=1);
+/**
+ * SPDX-FileCopyrightText: 2026 Nextcloud GmbH and Nextcloud contributors
+ * SPDX-License-Identifier: AGPL-3.0-or-later
+ */
+
+namespace OCA\Files_Sharing;
+
+use OC\Core\AppInfo\ConfigLexicon;
+use OCP\IAppConfig;
+use OCP\IURLGenerator;
+use Psr\Log\LoggerInterface;
+
+class PublicShareUrlGenerator {
+	private bool $invalidBaseUrlLogged = false;
+
+	public function __construct(
+		private IAppConfig $appConfig,
+		private IURLGenerator $urlGenerator,
+		private LoggerInterface $logger,
+	) {
+	}
+
+	public function getUrl(string $token): string {
+		$baseUrl = $this->getBaseUrl();
+		if ($baseUrl === null) {
+			return $this->urlGenerator->linkToRouteAbsolute('files_sharing.sharecontroller.showShare', ['token' => $token]);
+		}
+
+		// Keep the router as the single source of truth for the share link path,
+		// including a potential '/index.php' front controller prefix on instances
+		// without pretty URLs, and only swap the instance's webroot for the
+		// configured base URL.
+		$path = $this->urlGenerator->linkToRoute('files_sharing.sharecontroller.showShare', ['token' => $token]);
+		$webroot = $this->urlGenerator->getWebroot();
+		if ($webroot !== '' && str_starts_with($path, $webroot)) {
+			$path = substr($path, strlen($webroot));
+		}
+
+		return $baseUrl . $path;
+	}
+
+	private function getBaseUrl(): ?string {
+		$baseUrl = trim($this->appConfig->getValueString('core', ConfigLexicon::SHARE_LINK_BASE_URL, ''));
+		if ($baseUrl === '') {
+			return null;
+		}
+
+		if (filter_var($baseUrl, FILTER_VALIDATE_URL) !== false) {
+			$parts = parse_url($baseUrl);
+			if (is_array($parts)
+				&& isset($parts['host'])
+				&& in_array($parts['scheme'] ?? '', ['http', 'https'], true)
+				&& !isset($parts['user'])
+				&& !isset($parts['pass'])
+				&& !isset($parts['query'])
+				&& !isset($parts['fragment'])) {
+				return rtrim($baseUrl, '/');
+			}
+		}
+
+		// Do not log the configured value itself, it may contain credentials
+		if (!$this->invalidBaseUrlLogged) {
+			$this->invalidBaseUrlLogged = true;
+			$this->logger->warning(
+				'Ignoring invalid {configKey} app config value, falling back to the default base URL for public share links. Expected an absolute http(s) URL without credentials, query or fragment.',
+				['app' => 'files_sharing', 'configKey' => ConfigLexicon::SHARE_LINK_BASE_URL],
+			);
+		}
+
+		return null;
+	}
+}

apps/files_sharing/lib/SharesReminderJob.php

@@ -44,6 +44,7 @@ public function __construct(
 		private readonly IUserManager $userManager,
 		private readonly LoggerInterface $logger,
 		private readonly IURLGenerator $urlGenerator,
+		private readonly PublicShareUrlGenerator $publicShareUrlGenerator,
 		private readonly IFactory $l10nFactory,
 		private readonly IMailer $mailer,
 		private readonly Defaults $defaults,
@@ -231,9 +232,7 @@ private function prepareReminder(IShare $share): ?array {
 			]);
 		} else {
 			$reminderInfo['email'] = $sharedWith;
-			$reminderInfo['folderLink'] = $this->urlGenerator->linkToRouteAbsolute('files_sharing.sharecontroller.showShare', [
-				'token' => $share->getToken()
-			]);
+			$reminderInfo['folderLink'] = $this->publicShareUrlGenerator->getUrl($share->getToken());
 		}
 		if (empty($reminderInfo['email'])) {
 			return null;

apps/files_sharing/src/components/NewFileRequestDialog/NewFileRequestDialogFinish.vue

@@ -126,7 +126,7 @@ export default defineComponent({
 
 	computed: {
 		shareLink() {
-			return generateUrl('/s/{token}', { token: this.share.token }, { baseURL: getBaseUrl() })
+			return this.share.url ?? generateUrl('/s/{token}', { token: this.share.token }, { baseURL: getBaseUrl() })
 		},
 	},
 

apps/files_sharing/src/components/PublicShareLinkComponents.spec.ts

@@ -0,0 +1,55 @@
+/**
+ * SPDX-FileCopyrightText: 2026 Nextcloud GmbH and Nextcloud contributors
+ * SPDX-License-Identifier: AGPL-3.0-or-later
+ */
+
+import type * as Router from '@nextcloud/router'
+
+import { beforeEach, describe, expect, it, vi } from 'vitest'
+import NewFileRequestDialogFinish from './NewFileRequestDialog/NewFileRequestDialogFinish.vue'
+import SharingEntryLink from './SharingEntryLink.vue'
+
+const generateUrl = vi.hoisted(() => vi.fn())
+const getBaseUrl = vi.hoisted(() => vi.fn())
+vi.mock('@nextcloud/router', async (importOriginal) => ({
+	...await importOriginal<typeof Router>(),
+	generateUrl,
+	getBaseUrl,
+}))
+
+const components = [
+	['SharingEntryLink', SharingEntryLink],
+	['NewFileRequestDialogFinish', NewFileRequestDialogFinish],
+] as const
+
+beforeEach(() => {
+	vi.clearAllMocks()
+})
+
+describe.each(components)('%s public share link', (_name, component) => {
+	it('uses the complete URL returned by the server', () => {
+		generateUrl.mockReturnValue('http://nextcloud.local/s/token')
+
+		const shareLink = component.computed.shareLink.call({
+			share: {
+				token: 'token',
+				url: 'https://public-gateway.example/s/token',
+			},
+		})
+
+		expect(shareLink).toBe('https://public-gateway.example/s/token')
+		expect(generateUrl).not.toHaveBeenCalled()
+	})
+
+	it('falls back to the existing URL generation when the server URL is absent', () => {
+		getBaseUrl.mockReturnValue('/nextcloud')
+		generateUrl.mockReturnValue('http://nextcloud.local/nextcloud/s/token')
+
+		const shareLink = component.computed.shareLink.call({
+			share: { token: 'token' },
+		})
+
+		expect(shareLink).toBe('http://nextcloud.local/nextcloud/s/token')
+		expect(generateUrl).toHaveBeenCalledWith('/s/{token}', { token: 'token' }, { baseURL: '/nextcloud' })
+	})
+})

apps/files_sharing/src/components/SharingEntryLink.vue

@@ -561,7 +561,7 @@ export default {
 		 * @return {string}
 		 */
 		shareLink() {
-			return generateUrl('/s/{token}', { token: this.share.token }, { baseURL: getBaseUrl() })
+			return this.share.url ?? generateUrl('/s/{token}', { token: this.share.token }, { baseURL: getBaseUrl() })
 		},
 
 		/**

apps/files_sharing/src/models/Share.spec.ts

@@ -0,0 +1,19 @@
+/**
+ * SPDX-FileCopyrightText: 2026 Nextcloud GmbH and Nextcloud contributors
+ * SPDX-License-Identifier: AGPL-3.0-or-later
+ */
+
+import { describe, expect, it } from 'vitest'
+import Share from './Share.ts'
+
+describe('Share', () => {
+	it('exposes the complete public link URL returned by the server', () => {
+		const share = new Share({
+			id: 1,
+			share_type: 3,
+			url: 'https://public-gateway.example/prefix/s/token',
+		})
+
+		expect(share.url).toBe('https://public-gateway.example/prefix/s/token')
+	})
+})

apps/files_sharing/src/models/Share.ts

@@ -203,6 +203,13 @@ export default class Share {
 		return this._share.token
 	}
 
+	/**
+	 * Get the complete public share URL returned by the server
+	 */
+	get url(): string | undefined {
+		return this._share.url
+	}
+
 	/**
 	 * Set the public share token
 	 */

apps/files_sharing/tests/ApiTest.php

@@ -16,6 +16,7 @@
 use OC\Files\View;
 use OCA\Federation\TrustedServers;
 use OCA\Files_Sharing\Controller\ShareAPIController;
+use OCA\Files_Sharing\PublicShareUrlGenerator;
 use OCP\App\IAppManager;
 use OCP\AppFramework\OCS\OCSBadRequestException;
 use OCP\AppFramework\OCS\OCSException;
@@ -146,6 +147,7 @@ private function createOCS($userId) {
 			$mailer,
 			$tagManager,
 			$this->getEmailValidatorWithStrictEmailCheck(),
+			Server::get(PublicShareUrlGenerator::class),
 			$trustedServers,
 			$userId,
 		);
@@ -240,6 +242,30 @@ public function testCreateShareLink(): void {
 		$ocs->cleanup();
 	}
 
+	#[\PHPUnit\Framework\Attributes\Group(name: 'RoutingWeirdness')]
+	public function testCreateShareLinkWithConfiguredPublicLinkBaseUrl(): void {
+		$appConfig = Server::get(IAppConfig::class);
+		$appConfig->setValueString('core', ConfigLexicon::SHARE_LINK_BASE_URL, 'https://public-gateway.example/prefix/');
+
+		try {
+			$ocs = $this->createOCS(self::TEST_FILES_SHARING_API_USER1);
+			$result = $ocs->createShare($this->folder, Constants::PERMISSION_ALL, IShare::TYPE_LINK);
+			$ocs->cleanup();
+
+			$data = $result->getData();
+			$this->assertSame(
+				'https://public-gateway.example/prefix/s/' . $data['token'],
+				$data['url'],
+			);
+
+			$ocs = $this->createOCS(self::TEST_FILES_SHARING_API_USER1);
+			$ocs->deleteShare($data['id']);
+			$ocs->cleanup();
+		} finally {
+			$appConfig->deleteKey('core', ConfigLexicon::SHARE_LINK_BASE_URL);
+		}
+	}
+
 	#[\PHPUnit\Framework\Attributes\DataProvider(methodName: 'dataAllowFederationOnPublicShares')]
 	#[\PHPUnit\Framework\Attributes\Group(name: 'RoutingWeirdness')]
 	public function testCreateShareLinkPublicUpload(array $appConfig, int $permissions): void {