feat: Implement reference picker for document sections

Signed-off-by: Julius Härtl <jus@bitgrid.net>

appinfo/routes.php

@@ -34,6 +34,7 @@ return [
 		['name' => 'document#publicPage', 'url' => '/public', 'verb' => 'GET'],
 
 		['name' => 'document#editOnline', 'url' => 'editonline', 'verb' => 'GET'],
+		['name' => 'document#editOnlineTarget', 'url' => 'editonline/{fileId}/{target}', 'verb' => 'GET'],
 
 		// external api access
 		['name' => 'document#extAppGetData', 'url' => '/ajax/extapp/data/{fileId}', 'verb' => 'POST'],
@@ -87,5 +88,8 @@ return [
 		['name' => 'Federation#index', 'url' => '/api/v1/federation', 'verb' => 'GET'],
 		['name' => 'Federation#remoteWopiToken', 'url' => '/api/v1/federation', 'verb' => 'POST'],
 		['name' => 'Federation#initiatorUser', 'url' => '/api/v1/federation/user', 'verb' => 'POST'],
+
+		['name' => 'Target#getTargets', 'url' => '/api/v1/targets', 'verb' => 'GET'],
+		['name' => 'Target#getPreview', 'url' => '/api/v1/targets/preview', 'verb' => 'GET'],
 	],
 ];

composer.json

@@ -8,6 +8,9 @@
 			"php": "8.0"
 		}
 	},
+	"require": {
+		"ext-json": "*"
+	},
 	"require-dev": {
 		"roave/security-advisories": "dev-master",
 		"jakub-onderka/php-parallel-lint": "^1.0.0",

composer/composer/autoload_classmap.php

@@ -23,6 +23,7 @@ return array(
     'OCA\\Richdocuments\\Controller\\FederationController' => $baseDir . '/../lib/Controller/FederationController.php',
     'OCA\\Richdocuments\\Controller\\OCSController' => $baseDir . '/../lib/Controller/OCSController.php',
     'OCA\\Richdocuments\\Controller\\SettingsController' => $baseDir . '/../lib/Controller/SettingsController.php',
+    'OCA\\Richdocuments\\Controller\\TargetController' => $baseDir . '/../lib/Controller/TargetController.php',
     'OCA\\Richdocuments\\Controller\\TemplatesController' => $baseDir . '/../lib/Controller/TemplatesController.php',
     'OCA\\Richdocuments\\Controller\\WopiController' => $baseDir . '/../lib/Controller/WopiController.php',
     'OCA\\Richdocuments\\Db\\Asset' => $baseDir . '/../lib/Db/Asset.php',
@@ -40,6 +41,7 @@ return array(
     'OCA\\Richdocuments\\Listener\\CSPListener' => $baseDir . '/../lib/Listener/CSPListener.php',
     'OCA\\Richdocuments\\Listener\\FileCreatedFromTemplateListener' => $baseDir . '/../lib/Listener/FileCreatedFromTemplateListener.php',
     'OCA\\Richdocuments\\Listener\\LoadViewerListener' => $baseDir . '/../lib/Listener/LoadViewerListener.php',
+    'OCA\\Richdocuments\\Listener\\ReferenceListener' => $baseDir . '/../lib/Listener/ReferenceListener.php',
     'OCA\\Richdocuments\\Listener\\ShareLinkListener' => $baseDir . '/../lib/Listener/ShareLinkListener.php',
     'OCA\\Richdocuments\\Middleware\\WOPIMiddleware' => $baseDir . '/../lib/Middleware/WOPIMiddleware.php',
     'OCA\\Richdocuments\\Migration\\Version2060Date20200302131958' => $baseDir . '/../lib/Migration/Version2060Date20200302131958.php',
@@ -55,11 +57,14 @@ return array(
     'OCA\\Richdocuments\\Preview\\Office' => $baseDir . '/../lib/Preview/Office.php',
     'OCA\\Richdocuments\\Preview\\OpenDocument' => $baseDir . '/../lib/Preview/OpenDocument.php',
     'OCA\\Richdocuments\\Preview\\Pdf' => $baseDir . '/../lib/Preview/Pdf.php',
+    'OCA\\Richdocuments\\Reference\\OfficeTargetReferenceProvider' => $baseDir . '/../lib/Reference/OfficeTargetReferenceProvider.php',
     'OCA\\Richdocuments\\Service\\CapabilitiesService' => $baseDir . '/../lib/Service/CapabilitiesService.php',
     'OCA\\Richdocuments\\Service\\DemoService' => $baseDir . '/../lib/Service/DemoService.php',
     'OCA\\Richdocuments\\Service\\FederationService' => $baseDir . '/../lib/Service/FederationService.php',
+    'OCA\\Richdocuments\\Service\\FileTargetService' => $baseDir . '/../lib/Service/FileTargetService.php',
     'OCA\\Richdocuments\\Service\\FontService' => $baseDir . '/../lib/Service/FontService.php',
     'OCA\\Richdocuments\\Service\\InitialStateService' => $baseDir . '/../lib/Service/InitialStateService.php',
+    'OCA\\Richdocuments\\Service\\RemoteService' => $baseDir . '/../lib/Service/RemoteService.php',
     'OCA\\Richdocuments\\Service\\UserScopeService' => $baseDir . '/../lib/Service/UserScopeService.php',
     'OCA\\Richdocuments\\Settings\\Admin' => $baseDir . '/../lib/Settings/Admin.php',
     'OCA\\Richdocuments\\Settings\\Personal' => $baseDir . '/../lib/Settings/Personal.php',

composer/composer/autoload_static.php

@@ -38,6 +38,7 @@ class ComposerStaticInitRichdocuments
         'OCA\\Richdocuments\\Controller\\FederationController' => __DIR__ . '/..' . '/../lib/Controller/FederationController.php',
         'OCA\\Richdocuments\\Controller\\OCSController' => __DIR__ . '/..' . '/../lib/Controller/OCSController.php',
         'OCA\\Richdocuments\\Controller\\SettingsController' => __DIR__ . '/..' . '/../lib/Controller/SettingsController.php',
+        'OCA\\Richdocuments\\Controller\\TargetController' => __DIR__ . '/..' . '/../lib/Controller/TargetController.php',
         'OCA\\Richdocuments\\Controller\\TemplatesController' => __DIR__ . '/..' . '/../lib/Controller/TemplatesController.php',
         'OCA\\Richdocuments\\Controller\\WopiController' => __DIR__ . '/..' . '/../lib/Controller/WopiController.php',
         'OCA\\Richdocuments\\Db\\Asset' => __DIR__ . '/..' . '/../lib/Db/Asset.php',
@@ -55,6 +56,7 @@ class ComposerStaticInitRichdocuments
         'OCA\\Richdocuments\\Listener\\CSPListener' => __DIR__ . '/..' . '/../lib/Listener/CSPListener.php',
         'OCA\\Richdocuments\\Listener\\FileCreatedFromTemplateListener' => __DIR__ . '/..' . '/../lib/Listener/FileCreatedFromTemplateListener.php',
         'OCA\\Richdocuments\\Listener\\LoadViewerListener' => __DIR__ . '/..' . '/../lib/Listener/LoadViewerListener.php',
+        'OCA\\Richdocuments\\Listener\\ReferenceListener' => __DIR__ . '/..' . '/../lib/Listener/ReferenceListener.php',
         'OCA\\Richdocuments\\Listener\\ShareLinkListener' => __DIR__ . '/..' . '/../lib/Listener/ShareLinkListener.php',
         'OCA\\Richdocuments\\Middleware\\WOPIMiddleware' => __DIR__ . '/..' . '/../lib/Middleware/WOPIMiddleware.php',
         'OCA\\Richdocuments\\Migration\\Version2060Date20200302131958' => __DIR__ . '/..' . '/../lib/Migration/Version2060Date20200302131958.php',
@@ -70,11 +72,14 @@ class ComposerStaticInitRichdocuments
         'OCA\\Richdocuments\\Preview\\Office' => __DIR__ . '/..' . '/../lib/Preview/Office.php',
         'OCA\\Richdocuments\\Preview\\OpenDocument' => __DIR__ . '/..' . '/../lib/Preview/OpenDocument.php',
         'OCA\\Richdocuments\\Preview\\Pdf' => __DIR__ . '/..' . '/../lib/Preview/Pdf.php',
+        'OCA\\Richdocuments\\Reference\\OfficeTargetReferenceProvider' => __DIR__ . '/..' . '/../lib/Reference/OfficeTargetReferenceProvider.php',
         'OCA\\Richdocuments\\Service\\CapabilitiesService' => __DIR__ . '/..' . '/../lib/Service/CapabilitiesService.php',
         'OCA\\Richdocuments\\Service\\DemoService' => __DIR__ . '/..' . '/../lib/Service/DemoService.php',
         'OCA\\Richdocuments\\Service\\FederationService' => __DIR__ . '/..' . '/../lib/Service/FederationService.php',
+        'OCA\\Richdocuments\\Service\\FileTargetService' => __DIR__ . '/..' . '/../lib/Service/FileTargetService.php',
         'OCA\\Richdocuments\\Service\\FontService' => __DIR__ . '/..' . '/../lib/Service/FontService.php',
         'OCA\\Richdocuments\\Service\\InitialStateService' => __DIR__ . '/..' . '/../lib/Service/InitialStateService.php',
+        'OCA\\Richdocuments\\Service\\RemoteService' => __DIR__ . '/..' . '/../lib/Service/RemoteService.php',
         'OCA\\Richdocuments\\Service\\UserScopeService' => __DIR__ . '/..' . '/../lib/Service/UserScopeService.php',
         'OCA\\Richdocuments\\Settings\\Admin' => __DIR__ . '/..' . '/../lib/Settings/Admin.php',
         'OCA\\Richdocuments\\Settings\\Personal' => __DIR__ . '/..' . '/../lib/Settings/Personal.php',

lib/AppConfig.php

@@ -137,6 +137,10 @@ class AppConfig {
 		return $this->config->getAppValue(Application::APPNAME, self::WOPI_URL, '');
 	}
 
+	public function getDisableCertificateValidation(): bool {
+		return $this->config->getAppValue(Application::APPNAME, 'disable_certificate_verification', 'no') === 'yes';
+	}
+
 	public function getUseGroups(): ?array {
 		$groups = $this->config->getAppValue(Application::APPNAME, 'use_groups', '');
 		if ($groups === '') {

lib/AppInfo/Application.php

@@ -31,6 +31,7 @@ use OCA\Richdocuments\Listener\BeforeFetchPreviewListener;
 use OCA\Richdocuments\Listener\CSPListener;
 use OCA\Richdocuments\Listener\FileCreatedFromTemplateListener;
 use OCA\Richdocuments\Listener\LoadViewerListener;
+use OCA\Richdocuments\Listener\ReferenceListener;
 use OCA\Richdocuments\Listener\ShareLinkListener;
 use OCA\Richdocuments\Middleware\WOPIMiddleware;
 use OCA\Richdocuments\PermissionManager;
@@ -39,6 +40,7 @@ use OCA\Richdocuments\Preview\MSWord;
 use OCA\Richdocuments\Preview\OOXML;
 use OCA\Richdocuments\Preview\OpenDocument;
 use OCA\Richdocuments\Preview\Pdf;
+use OCA\Richdocuments\Reference\OfficeTargetReferenceProvider;
 use OCA\Richdocuments\Service\CapabilitiesService;
 use OCA\Richdocuments\Template\CollaboraTemplateProvider;
 use OCA\Richdocuments\WOPI\DiscoveryManager;
@@ -47,6 +49,7 @@ use OCP\AppFramework\App;
 use OCP\AppFramework\Bootstrap\IBootContext;
 use OCP\AppFramework\Bootstrap\IBootstrap;
 use OCP\AppFramework\Bootstrap\IRegistrationContext;
+use OCP\Collaboration\Reference\RenderReferenceEvent;
 use OCP\Files\Template\FileCreatedFromTemplateEvent;
 use OCP\Files\Template\ITemplateManager;
 use OCP\Files\Template\TemplateFileCreator;
@@ -73,6 +76,8 @@ class Application extends App implements IBootstrap {
 		$context->registerEventListener(LoadViewer::class, LoadViewerListener::class);
 		$context->registerEventListener(ShareLinkAccessedEvent::class, ShareLinkListener::class);
 		$context->registerEventListener(BeforePreviewFetchedEvent::class, BeforeFetchPreviewListener::class);
+		$context->registerEventListener(RenderReferenceEvent::class, ReferenceListener::class);
+		$context->registerReferenceProvider(OfficeTargetReferenceProvider::class);
 	}
 
 	public function boot(IBootContext $context): void {

lib/Controller/DocumentController.php

@@ -39,6 +39,8 @@ use OCP\Share\IManager;
 class DocumentController extends Controller {
 	use DocumentTrait;
 
+	public const SESSION_FILE_TARGET = 'richdocuments_openfile_target';
+
 	/** @var ?string */
 	private $uid;
 	/** @var IConfig */
@@ -140,12 +142,13 @@ class DocumentController extends Controller {
 
 	/**
 	 * @NoAdminRequired
+	 * @UseSession
 	 *
 	 * @param string $fileId
 	 * @param string|null $path
 	 * @return RedirectResponse|TemplateResponse
 	 */
-	public function index($fileId, $path = null) {
+	public function index($fileId, ?string $path = null) {
 		try {
 			$folder = $this->rootFolder->getUserFolder($this->uid);
 
@@ -188,6 +191,14 @@ class DocumentController extends Controller {
 				'path' => $folder->getRelativePath($item->getPath()),
 			];
 
+			$targetData = $this->session->get(self::SESSION_FILE_TARGET);
+			if ($targetData) {
+				$this->session->remove(self::SESSION_FILE_TARGET);
+				if ($targetData['fileId'] === $item->getId()) {
+					$params['target'] = $targetData['target'];
+				}
+			}
+
 			$encryptionManager = \OC::$server->getEncryptionManager();
 			if ($encryptionManager->isEnabled()) {
 				// Update the current file to be accessible with system public shared key
@@ -403,8 +414,9 @@ class DocumentController extends Controller {
 	/**
 	 * @NoCSRFRequired
 	 * @NoAdminRequired
+	 * @UseSession
 	 */
-	public function editOnline(string $path = null, string $userId = null) {
+	public function editOnline(string $path = null, ?string $userId = null, ?string $target = null) {
 		if ($path === null) {
 			return $this->renderErrorPage('No path provided');
 		}
@@ -428,6 +440,46 @@ class DocumentController extends Controller {
 		try {
 			$userFolder = $this->rootFolder->getUserFolder($userId);
 			$file = $userFolder->get($path);
+			if ($target !== null) {
+				$this->session->set(self::SESSION_FILE_TARGET, [
+					'fileId' => $file->getId(),
+					'target' => $target,
+				]);
+			}
+			$redirectUrl = $this->urlGenerator->getAbsoluteURL('/index.php/f/' . $file->getId());
+			return new RedirectResponse($redirectUrl);
+		} catch (NotFoundException $e) {
+		} catch (NotPermittedException $e) {
+		} catch (NoUserException $e) {
+		}
+
+		return $this->renderErrorPage('File not found', Http::STATUS_NOT_FOUND);
+	}
+
+	/**
+	 * @NoCSRFRequired
+	 * @NoAdminRequired
+	 * @UseSession
+	 */
+	public function editOnlineTarget(int $fileId, ?string $target = null) {
+		if (!$this->uid) {
+			return $this->renderErrorPage('File not found', Http::STATUS_NOT_FOUND);
+		}
+
+		try {
+			$userFolder = $this->rootFolder->getUserFolder($this->uid);
+			$files = $userFolder->getById($fileId);
+			$file = array_shift($files);
+			if (!$file) {
+				return $this->renderErrorPage('File not found', Http::STATUS_NOT_FOUND);
+			}
+
+			if ($target !== null) {
+				$this->session->set(self::SESSION_FILE_TARGET, [
+					'fileId' => $file->getId(),
+					'target' => $target,
+				]);
+			}
 			$redirectUrl = $this->urlGenerator->getAbsoluteURL('/index.php/f/' . $file->getId());
 			return new RedirectResponse($redirectUrl);
 		} catch (NotFoundException $e) {

lib/Controller/TargetController.php

@@ -0,0 +1,75 @@
+<?php
+
+namespace OCA\Richdocuments\Controller;
+
+use OC\User\NoUserException;
+use OCA\Richdocuments\Service\FileTargetService;
+use OCP\AppFramework\Http;
+use OCP\AppFramework\Http\DataDisplayResponse;
+use OCP\AppFramework\Http\DataResponse;
+use OCP\AppFramework\Http\Response;
+use OCP\Files\File;
+use OCP\Files\IRootFolder;
+use OCP\Files\NotFoundException;
+use OCP\Files\NotPermittedException;
+use OCP\IRequest;
+
+class TargetController extends \OCP\AppFramework\OCSController {
+
+	public function __construct(
+		string $appName,
+		IRequest $request,
+		private FileTargetService $fileTargetService,
+		private IRootFolder $rootFolder,
+		private ?string $userId,
+	) {
+		parent::__construct($appName, $request);
+	}
+
+	/**
+	 * @NoAdminRequired
+	 */
+	public function getTargets(string $path): DataResponse {
+		try {
+			$file = $this->getFile($path);
+			return new DataResponse($this->fileTargetService->getFileTargets($file));
+		} catch (NotFoundException $e) {
+		}
+
+		return new DataResponse('File not found', Http::STATUS_NOT_FOUND);
+	}
+
+	/**
+	 * @NoAdminRequired
+	 * @NoCSRFRequired
+	 */
+	public function getPreview(string $path, string $target): Response {
+		try {
+			$file = $this->getFile($path);
+			return new DataDisplayResponse(
+				$this->fileTargetService->getTargetPreview($file, $target),
+				Http::STATUS_OK,
+				['Content-Type' => 'image/png']
+			);
+		} catch (NotFoundException $e) {
+			return new DataResponse('File not found', Http::STATUS_NOT_FOUND);
+		}
+	}
+
+	/**
+	 * @throws NotFoundException
+	 */
+	private function getFile(string $path): File {
+		try {
+			$file = $this->rootFolder->getUserFolder($this->userId)->get($path);
+
+			if (!$file instanceof File) {
+				throw new NotFoundException();
+			}
+
+			return $file;
+		} catch (NotFoundException|NotPermittedException|NoUserException $e) {
+			throw new NotFoundException();
+		}
+	}
+}

lib/Listener/ReferenceListener.php

@@ -0,0 +1,45 @@
+<?php
+
+declare(strict_types=1);
+
+/**
+ * @copyright Copyright (c) 2023 Julius Härtl <jus@bitgrid.net>
+ *
+ * @author Julius Härtl <jus@bitgrid.net>
+ *
+ * @license GNU AGPL version 3 or any later version
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU Affero General Public License as
+ * published by the Free Software Foundation, either version 3 of the
+ * License, or (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ * GNU Affero General Public License for more details.
+ *
+ * You should have received a copy of the GNU Affero General Public License
+ * along with this program. If not, see <http://www.gnu.org/licenses/>.
+ *
+ */
+
+
+
+namespace OCA\Richdocuments\Listener;
+
+use OCP\Collaboration\Reference\RenderReferenceEvent;
+use OCP\EventDispatcher\Event;
+use OCP\EventDispatcher\IEventListener;
+use OCP\Util;
+
+/** @template-implements IEventListener<Event|RenderReferenceEvent> */
+class ReferenceListener implements IEventListener {
+	public function handle(Event $event): void {
+		if (!$event instanceof RenderReferenceEvent) {
+			return;
+		}
+
+		Util::addScript('richdocuments', 'richdocuments-reference');
+	}
+}

lib/Reference/OfficeTargetReferenceProvider.php

@@ -0,0 +1,148 @@
+<?php
+
+namespace OCA\Richdocuments\Reference;
+
+use Exception;
+use OCA\Richdocuments\AppInfo\Application;
+use OCA\Richdocuments\Service\FileTargetService;
+use OCP\Collaboration\Reference\ADiscoverableReferenceProvider;
+use OCP\Collaboration\Reference\IReference;
+use OCP\Collaboration\Reference\Reference;
+use OCP\Files\IMimeTypeDetector;
+use OCP\Files\IRootFolder;
+use OCP\IL10N;
+use OCP\IPreview;
+use OCP\IURLGenerator;
+use Psr\Log\LoggerInterface;
+
+class OfficeTargetReferenceProvider extends ADiscoverableReferenceProvider {
+
+	public function __construct(
+		private FileTargetService $fileTargetService,
+		private IURLGenerator $urlGenerator,
+		private IL10N $l10n,
+		private IPreview $previewManager,
+		private IMimeTypeDetector $mimeTypeDetector,
+		private IRootFolder $rootFolder,
+		private LoggerInterface $logger,
+		private ?string $userId,
+	) {
+	}
+
+	/**
+	 * @inheritDoc
+	 */
+	public function matchReference(string $referenceText): bool {
+		$start = $this->urlGenerator->getAbsoluteURL('/apps/' . Application::APPNAME);
+		$startIndex = $this->urlGenerator->getAbsoluteURL('/index.php/apps/' . Application::APPNAME);
+
+		$noIndexMatch = preg_match('/^' . preg_quote($start, '/') . '\/editonline\/([0-9]+)\/(.*)$/', $referenceText) === 1;
+		$indexMatch = preg_match('/^' . preg_quote($startIndex, '/') . '\/editonline\/([0-9]+)\/(.*)$/', $referenceText) === 1;
+
+		return $noIndexMatch || $indexMatch;
+	}
+
+	/**
+	 * @inheritDoc
+	 */
+	public function resolveReference(string $referenceText): ?IReference {
+		$start = $this->urlGenerator->getAbsoluteURL('/apps/' . Application::APPNAME);
+		$startIndex = $this->urlGenerator->getAbsoluteURL('/index.php/apps/' . Application::APPNAME);
+
+		$matched = preg_match('/^' . preg_quote($start, '/') . '\/editonline\/([0-9]+)\/(.*)$/', $referenceText, $matches) === 1;
+		if (!$matched) {
+			$matched = preg_match('/^' . preg_quote($startIndex, '/') . '\/editonline\/([0-9]+)\/(.*)$/', $referenceText, $matches) === 1;
+		}
+
+		if (!$matched) {
+			return null;
+		}
+
+		$fileId = (int)$matches[1];
+		$target = urldecode($matches[2]);
+
+		try {
+			$userFolder = $this->rootFolder->getUserFolder($this->userId);
+			$files = $userFolder->getById($fileId);
+			$file = array_shift($files);
+		} catch (Exception $e) {
+			$this->logger->info('Failed to get file for office target reference: ' . $fileId, ['exception' => $e]);
+			return null;
+		}
+
+		if ($file === null) {
+			return null;
+		}
+
+		$label = null;
+		if ($this->previewManager->isMimeSupported($file->getMimeType())) {
+			$preview = $this->urlGenerator->linkToRouteAbsolute('core.Preview.getPreviewByFileId', ['x' => 1600, 'y' => 630, 'fileId' => $fileId]);
+		} else {
+			$fileTypeIconUrl = $this->mimeTypeDetector->mimeTypeIcon($file->getMimeType());
+			$preview = $fileTypeIconUrl;
+		}
+		$targets = $this->fileTargetService->getFileTargets($file);
+		foreach ($targets as $value) {
+			$entries = $value['entries'];
+			foreach ($entries as $entry) {
+				if ($entry['id'] === $target) {
+					$label = $entry['name'];
+					$preview = $entry['preview'] ?? $preview;
+					break 2;
+				}
+			}
+		}
+		$reference = new Reference($referenceText);
+		$reference->setTitle($label ?? $file->getName());
+		$reference->setDescription($label ? $file->getName(): null);
+		$reference->setUrl($referenceText);
+
+		$reference->setImageUrl($preview);
+
+		/*
+		FIXME: THis requires a change in the file provider to properly open the target link still
+		$reference->setRichObject('file', [
+			'id' => $file->getId(),
+			'name' => $file->getName() . ' · ' . $label,
+			'size' => $file->getSize(),
+			'path' => $userFolder->getRelativePath($file->getPath()),
+			'link' => $reference->getUrl(),
+			'mimetype' => $file->getMimetype(),
+			'mtime' => $file->getMTime(),
+			'preview-available' => $this->previewManager->isAvailable($file)
+		]);
+		*/
+
+		return $reference;
+	}
+
+	/**
+	 * @inheritDoc
+	 */
+	public function getCachePrefix(string $referenceId): string {
+		return $referenceId;
+	}
+
+	/**
+	 * @inheritDoc
+	 */
+	public function getCacheKey(string $referenceId): ?string {
+		return $this->userId ?? '';
+	}
+
+	public function getId(): string {
+		return 'office-target';
+	}
+
+	public function getTitle(): string {
+		return $this->l10n->t('Link to office document section');
+	}
+
+	public function getOrder(): int {
+		return 90;
+	}
+
+	public function getIconUrl(): string {
+		return $this->urlGenerator->getAbsoluteURL($this->urlGenerator->imagePath(Application::APPNAME, 'app-dark.svg'));
+	}
+}

lib/Service/FileTargetService.php

@@ -0,0 +1,92 @@
+<?php
+
+namespace OCA\Richdocuments\Service;
+
+use OCP\Files\File;
+use OCP\Files\IRootFolder;
+use OCP\ICacheFactory;
+use OCP\IL10N;
+use Psr\Log\LoggerInterface;
+
+class FileTargetService {
+
+	public function __construct(
+		private RemoteService $remoteService,
+		private ICacheFactory $cacheFactory,
+		private IRootFolder $rootFolder,
+		private LoggerInterface $logger,
+		private IL10N $l10n,
+		private ?string $userId,
+	) {
+	}
+
+	public function getFileTargets(File $file): array {
+		$cache = $this->cacheFactory->createDistributed('richdocuments-filetarget');
+		$cacheKey = $file->getId() . '_' . $file->getMTime();
+		if ($cached = $cache->get($cacheKey)) {
+			return $cached;
+		}
+
+		$result = $this->remoteService->fetchTargets($file);
+
+		$categories = [];
+
+		$targets = $result['Targets'];
+
+		$filePath = $this->rootFolder->getUserFolder($this->userId)->getRelativePath($file->getPath());
+
+		// Limit what we support to display
+		if (isset($targets['Headings'])) {
+			$categories['headings'] = [
+				'label' => $this->l10n->t('Headings'),
+				'entries' => $this->mapTargets($filePath, $targets['Headings'])
+			];
+		}
+
+		if (isset($targets['Sections'])) {
+			$categories['sections'] = [
+				'label' => $this->l10n->t('Sections'),
+				'entries' => $this->mapTargets($filePath, $targets['Sections'])
+			];
+		}
+
+		if (isset($targets['Images'])) {
+			$categories['images'] = [
+				'label' => $this->l10n->t('Images'),
+				'entries' => $this->mapTargets($filePath, $targets['Images'])
+			];
+		}
+
+		if (isset($targets['Sheets'])) {
+			$categories['sheets'] = [
+				'label' => $this->l10n->t('Sheets'),
+				'entries' => $this->mapTargets($filePath, $targets['Sheets'])
+			];
+		}
+
+		$cache->set($cacheKey, $categories);
+
+		return $categories;
+	}
+
+	public function getTargetPreview($file, $target) {
+		return $this->remoteService->fetchTargetThumbnail($file, $target);
+	}
+
+	private function mapTargets(string $filePath, array $targets): array {
+		$result = [];
+		foreach ($targets as $name => $identifier) {
+			$result[] = [
+				'id' => $identifier,
+				'name' => $name,
+				// Disable previews for now as they may cause endless requests against Collabora
+				// 'preview' => $this->urlGenerator->linkToOCSRouteAbsolute('richdocuments.Target.getPreview', [
+				// 	'path' => $filePath,
+				// 	'target' => $identifier,
+				// ]),
+			];
+
+		}
+		return $result;
+	}
+}

lib/Service/RemoteService.php

@@ -0,0 +1,88 @@
+<?php
+
+namespace OCA\Richdocuments\Service;
+
+use Exception;
+use OCA\Richdocuments\AppConfig;
+use OCP\Files\File;
+use OCP\Files\NotFoundException;
+use OCP\Http\Client\IClientService;
+use Psr\Log\LoggerInterface;
+
+class RemoteService {
+
+	public const REMOTE_TIMEOUT_DEFAULT = 25;
+
+	public function __construct(
+		private AppConfig $appConfig,
+		private IClientService $clientService,
+		private LoggerInterface $logger,
+	) {
+	}
+
+	public function fetchTargets($file): array {
+		$client = $this->clientService->newClient();
+		try {
+			$response = $client->put(
+				$this->appConfig->getCollaboraUrlInternal(). '/cool/extract-link-targets',
+				$this->getRequestOptionsForFile($file)
+			);
+		} catch (Exception $e) {
+			$this->logger->warning('Failed to fetch extract-link-targets', ['exception' => $e]);
+			return [];
+		}
+
+		$json = trim($response->getBody());
+		$json = str_replace(['", }', "\r\n", "\t"], ['" }', '\r\n', '\t'], $json);
+		try {
+			$result = json_decode($json, true, 512, JSON_THROW_ON_ERROR);
+		} catch (\JsonException $e) {
+			$this->logger->warning('Failed to parse extract-link-targets response', ['exception' => $e]);
+			return [];
+		}
+		return $result;
+	}
+
+	public function fetchTargetThumbnail(File $file, string $target): ?string {
+		$client = $this->clientService->newClient();
+		try {
+			$response = $client->put($this->appConfig->getCollaboraUrlInternal(). '/cool/get-thumbnail', $this->getRequestOptionsForFile($file, $target));
+			return (string)$response->getBody();
+		} catch (Exception $e) {
+			$this->logger->info('Failed to fetch target thumbnail', ['exception' => $e]);
+		}
+		return null;
+	}
+
+	private function getRequestOptionsForFile(File $file, ?string $target = null): array {
+		$useTempFile = $file->isEncrypted() || !$file->getStorage()->isLocal();
+		if ($useTempFile) {
+			$localFile = $file->getStorage()->getLocalFile($file->getInternalPath());
+			if (!is_string($localFile)) {
+				throw new NotFoundException('Could not get local file');
+			}
+			$stream = fopen($localFile, 'rb');
+		} else {
+			$stream = $file->fopen('rb');
+		}
+
+		$options = [
+			'timeout' => self::REMOTE_TIMEOUT_DEFAULT,
+			'multipart' => [
+				['name' => $file->getName(), 'contents' => $stream],
+				['name' => 'target', 'contents' => $target]
+			]
+		];
+
+		if ($this->appConfig->getDisableCertificateValidation()) {
+			$options['verify'] = false;
+		}
+
+		$options['headers'] = [
+			'User-Agent' => 'Nextcloud Server / richdocuments',
+			'Accept' => 'application/json',
+		];
+
+		return $options;
+	}
+}

src/document.js

@@ -247,7 +247,7 @@ const documentsMain = {
 			$(document.body).addClass('claro')
 			$(document.body).prepend(documentsMain.UI.container)
 
-			const urlsrc = getWopiUrl({ fileId, title, readOnly: false, closeButton: !documentsMain.hideCloseButton, revisionHistory: !documentsMain.isPublic })
+			const urlsrc = getWopiUrl({ fileId, title, readOnly: false, closeButton: !documentsMain.hideCloseButton, revisionHistory: !documentsMain.isPublic, target: Config.get('target') })
 
 			// access_token - must be passed via a form post
 			const accessToken = encodeURIComponent(documentsMain.token)

src/helpers/url.js

@@ -32,7 +32,7 @@ const getSearchParam = (name) => {
 	return decodeURI(results[1]) || ''
 }
 
-const getWopiUrl = ({ fileId, title, readOnly, closeButton, revisionHistory }) => {
+const getWopiUrl = ({ fileId, title, readOnly, closeButton, revisionHistory, target = undefined }) => {
 	// Only set the revision history parameter if the versions app is enabled
 	revisionHistory = revisionHistory && window?.oc_appswebroots?.files_versions
 
@@ -53,6 +53,7 @@ const getWopiUrl = ({ fileId, title, readOnly, closeButton, revisionHistory }) =
 		+ (closeButton ? '&closebutton=1' : '')
 		+ (revisionHistory ? '&revisionhistory=1' : '')
 		+ (readOnly ? '&permission=readonly' : '')
+		+ (target ? '&target=' + encodeURIComponent(target) : '')
 }
 
 const getDocumentUrlFromTemplate = (templateId, fileName, fileDir, fillWithTemplate) => {

src/reference.js

@@ -0,0 +1,45 @@
+/*
+ * @copyright Copyright (c) 2023 Julius Härtl <jus@bitgrid.net>
+ *
+ * @author Julius Härtl <jus@bitgrid.net>
+ *
+ * @license GNU AGPL version 3 or any later version
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU Affero General Public License as
+ * published by the Free Software Foundation, either version 3 of the
+ * License, or (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ * GNU Affero General Public License for more details.
+ *
+ * You should have received a copy of the GNU Affero General Public License
+ * along with this program. If not, see <http://www.gnu.org/licenses/>.
+ */
+
+import Vue from 'vue'
+import { translate as t } from '@nextcloud/l10n'
+
+import { registerCustomPickerElement, NcCustomPickerRenderResult } from '@nextcloud/vue/dist/Components/NcRichText.js'
+
+import DocumentTargetPicker from './view/DocumentTargetPicker.vue'
+
+Vue.mixin({
+	methods: {
+		t,
+	},
+})
+registerCustomPickerElement('office-target', (el, { providerId, accessible }) => {
+	const Element = Vue.extend(DocumentTargetPicker)
+	const vueElement = new Element({
+		propsData: {
+			providerId,
+			accessible,
+		},
+	}).$mount(el)
+	return new NcCustomPickerRenderResult(vueElement.$el, vueElement)
+}, (el, renderResult) => {
+	renderResult.object.$destroy()
+})

src/view/DocumentTargetPicker.vue

@@ -0,0 +1,204 @@
+<!--
+  - @copyright Copyright (c) 2023 Julius Härtl <jus@bitgrid.net>
+  -
+  - @author Julius Härtl <jus@bitgrid.net>
+  -
+  - @license GNU AGPL version 3 or any later version
+  -
+  - This program is free software: you can redistribute it and/or modify
+  - it under the terms of the GNU Affero General Public License as
+  - published by the Free Software Foundation, either version 3 of the
+  - License, or (at your option) any later version.
+  -
+  - This program is distributed in the hope that it will be useful,
+  - but WITHOUT ANY WARRANTY; without even the implied warranty of
+  - MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+  - GNU Affero General Public License for more details.
+  -
+  - You should have received a copy of the GNU Affero General Public License
+  - along with this program. If not, see <http://www.gnu.org/licenses/>.
+  -->
+
+<template>
+	<div v-if="filePath === null" class="office-target-picker">
+		<div ref="picker" class="reference-file-picker" />
+	</div>
+	<div v-else class="office-target-picker">
+		<h2>{{ t('richdocuments', 'Link to office document section') }}</h2>
+		<NcLoadingIcon v-if="!sections || !fileId" :size="44" />
+		<div v-else>
+			<NcEmptyContent v-if="sections.length === 0" :title="t('richdocuments', 'Could not find any section in the document')">
+				<template #icon>
+					<TableOfContentsIcon />
+				</template>
+			</NcEmptyContent>
+			<template v-else>
+				<div v-for="section in sections" :key="section.label">
+					<h3>{{ section.label }}</h3>
+					<ul>
+						<NcListItem v-for="entry in section.entries"
+							:key="entry.id"
+							:title="entry.name"
+							:class="{ 'list-item__wrapper--active': entry.id === target }"
+							@click="setTarget(entry)">
+							<template v-if="entry.preview" #icon>
+								<img :src="entry.preview">
+							</template>
+						</NcListItem>
+					</ul>
+				</div>
+			</template>
+			<div v-if="sections.length !== 0" class="office-target-picker__buttons">
+				<NcButton type="primary" :disabled="!target" @click="submit()">
+					{{ t('richdocuments', 'Link to office document section') }}
+				</NcButton>
+			</div>
+		</div>
+	</div>
+</template>
+
+<script>
+import { FilePickerType } from '@nextcloud/dialogs'
+import { generateUrl, generateOcsUrl } from '@nextcloud/router'
+import axios from '@nextcloud/axios'
+import { NcButton, NcEmptyContent, NcListItem, NcLoadingIcon } from '@nextcloud/vue'
+import TableOfContentsIcon from 'vue-material-design-icons/TableOfContents.vue'
+
+export default {
+	name: 'DocumentTargetPicker',
+	components: {
+		NcButton,
+		NcEmptyContent,
+		NcListItem,
+		NcLoadingIcon,
+		TableOfContentsIcon,
+	},
+	props: {
+		providerId: {
+			type: String,
+			required: true,
+		},
+		accessible: {
+			type: Boolean,
+			default: false,
+		},
+	},
+	data() {
+		return {
+			fileId: null,
+			filePath: null,
+			target: null,
+			sections: null,
+		}
+	},
+	mounted() {
+		this.openFilePicker()
+		window.addEventListener('click', this.onWindowClick)
+	},
+	beforeDestroy() {
+		window.removeEventListener('click', this.onWindowClick)
+	},
+	methods: {
+		onWindowClick(e) {
+			if (e.target.tagName === 'A' && e.target.classList.contains('oc-dialog-close')) {
+				this.$emit('cancel')
+			}
+		},
+		async openFilePicker() {
+			const self = this
+			OC.dialogs.filepicker(
+				t('files', 'Select file or folder to link to'),
+				function(file) {
+					const client = OC.Files.getClient()
+					client.getFileInfo(file).then((_status, fileInfo) => {
+						self.fileId = fileInfo.id
+					})
+					self.filePath = file
+					self.fetchReferences()
+				},
+				false, // multiselect
+				OC.getCapabilities().richdocuments.mimetypes, // mime filter
+				false, // modal
+				FilePickerType.Choose, // type
+				'',
+				{
+					target: this.$refs.picker,
+				},
+			)
+		},
+		setTarget(entry) {
+			this.target = entry.id
+		},
+		submit() {
+			const fileLink = window.location.protocol + '//' + window.location.host
+				+ generateUrl('/apps/richdocuments/editonline/{fileId}/{target}', { fileId: this.fileId, target: this.target })
+			this.$emit('submit', fileLink)
+		},
+		async fetchReferences() {
+			const response = await axios.get(generateOcsUrl('/apps/richdocuments/api/v1/targets'), {
+				params: {
+					path: this.filePath,
+				},
+			})
+			this.sections = response.data.ocs.data
+		},
+	},
+}
+</script>
+
+<style scoped lang="scss">
+.reference-file-picker {
+	flex-grow: 1;
+
+	&:deep(.oc-dialog) {
+		transform: none !important;
+		box-shadow: none !important;
+		flex-grow: 1 !important;
+		position: static !important;
+		width: 100% !important;
+		height: auto !important;
+		padding: 0 !important;
+		max-width: initial;
+
+		.oc-dialog-close {
+			display: none;
+		}
+
+		.oc-dialog-buttonrow.onebutton.aside {
+			position: absolute;
+			padding: 12px 32px;
+		}
+
+		.oc-dialog-content {
+			max-width: 100% !important;
+		}
+	}
+}
+
+.office-target-picker {
+	margin: calc(var(--default-grid-baseline) * 4);
+	flex-grow: 1;
+	height: 80vh;
+
+	&__buttons {
+		position: sticky;
+		bottom: 12px;
+		display: flex;
+		align-items: flex-end;
+		flex-direction: column;
+	}
+}
+
+h3 {
+	font-weight: bold;
+	color: var(--color-primary-element);
+	font-size: var(--default-font-size);
+	line-height: 44px;
+	white-space: nowrap;
+	overflow: hidden;
+	text-overflow: ellipsis;
+	opacity: .7;
+	box-shadow: none !important;
+	flex-shrink: 0;
+}
+</style>

src/view/Office.vue

@@ -334,7 +334,7 @@ export default {
 		z-index: 1;
 		top: 0;
 		left: 0;
-		background-color: #fff;
+		background-color: var(--color-main-background);
 		&.debug {
 			opacity: .5;
 		}

webpack.js

@@ -10,6 +10,7 @@ webpackConfig.entry = {
 	document: path.join(__dirname, 'src', 'document.js'),
 	admin: path.join(__dirname, 'src', 'admin.js'),
 	personal: path.join(__dirname, 'src', 'personal.js'),
+	reference: path.join(__dirname, 'src', 'reference.js'),
 }
 
 webpackRules.RULE_JS.test = /\.m?js$/