fix(sync): If `baseVersionEtag` changed, reset frontend

`baseVersionEtag` changes when a new document session got initialized,
e.g. after an old document session without session clients got cleaned
up, or because the markdown file got changed via webdav.

Detect this in the client and ask the user to reload the page for
resetting the session.

Signed-off-by: Jonas <jonas@freesources.org>

lib/Controller/PublicSessionController.php

@@ -80,8 +80,8 @@ class PublicSessionController extends PublicShareController implements ISessionA
 
 	#[NoAdminRequired]
 	#[PublicPage]
-	public function create(string $token, ?string $file = null, ?string $guestName = null): DataResponse {
-		return $this->apiService->create(null, $file, $token, $guestName);
+	public function create(string $token, ?string $file = null, ?string $baseVersionEtag = null, ?string $guestName = null): DataResponse {
+		return $this->apiService->create(null, $file, $baseVersionEtag, $token, $guestName);
 	}
 
 	#[NoAdminRequired]

lib/Controller/SessionController.php

@@ -57,8 +57,8 @@ class SessionController extends ApiController implements ISessionAwareController
 	}
 
 	#[NoAdminRequired]
-	public function create(?int $fileId = null, ?string $file = null): DataResponse {
-		return $this->apiService->create($fileId, $file, null, null);
+	public function create(?int $fileId = null, ?string $file = null, ?string $baseVersionEtag = null): DataResponse {
+		return $this->apiService->create($fileId, $file, $baseVersionEtag, null, null);
 	}
 
 	#[NoAdminRequired]

lib/Service/ApiService.php

@@ -71,7 +71,7 @@ class ApiService {
 		$this->l10n = $l10n;
 	}
 
-	public function create(?int $fileId = null, ?string $filePath = null, ?string $token = null, ?string $guestName = null): DataResponse {
+	public function create(?int $fileId = null, ?string $filePath = null, ?string $baseVersionEtag = null, ?string $token = null, ?string $guestName = null): DataResponse {
 		try {
 			if ($token) {
 				$file = $this->documentService->getFileByShareToken($token, $this->request->getParam('filePath'));
@@ -115,6 +115,9 @@ class ApiService {
 			$this->sessionService->removeInactiveSessionsWithoutSteps($file->getId());
 			$document = $this->documentService->getDocument($file->getId());
 			$freshSession = $document === null;
+			if ($baseVersionEtag && $baseVersionEtag !== $document?->getBaseVersionEtag()) {
+				return new DataResponse($this->l10n->t('Editing session has expired. Please reload the page.'), Http::STATUS_CONFLICT);
+			}
 
 			if ($freshSession) {
 				$this->logger->info('Create new document of ' . $file->getId());

src/components/Editor.vue

@@ -374,6 +374,7 @@ export default {
 				guestName,
 				shareToken: this.shareToken,
 				filePath: this.relativePath,
+				baseVersionEtag: this.$syncService?.baseVersionEtag,
 				forceRecreate: this.forceRecreate,
 				serialize: this.isRichEditor
 					? (content) => createMarkdownSerializer(this.$editor.schema).serialize(content ?? this.$editor.state.doc)

src/services/SessionApi.js

@@ -38,9 +38,10 @@ class SessionApi {
 		this.#options = options
 	}
 
-	open({ fileId }) {
+	open({ fileId, baseVersionEtag }) {
 		return axios.put(this.#url(`session/${fileId}/create`), {
 			fileId,
+			baseVersionEtag,
 			filePath: this.#options.filePath,
 			token: this.#options.shareToken,
 			guestName: this.#options.guestName,

src/services/SyncService.js

@@ -68,7 +68,7 @@ class SyncService {
 
 	#sendIntervalId
 
-	constructor({ serialize, getDocumentState, ...options }) {
+	constructor({ baseVersionEtag, serialize, getDocumentState, ...options }) {
 		/** @type {import('mitt').Emitter<import('./SyncService').EventTypes>} _bus */
 		this._bus = mitt()
 
@@ -82,6 +82,7 @@ class SyncService {
 		this.lastStepPush = Date.now()
 
 		this.version = null
+		this.baseVersionEtag = baseVersionEtag
 		this.sending = false
 		this.#sendIntervalId = null
 
@@ -94,7 +95,7 @@ class SyncService {
 
 		const connect = initialSession
 			? Promise.resolve(new Connection({ data: initialSession }, {}))
-			: this._api.open({ fileId })
+			: this._api.open({ fileId, baseVersionEtag: this.baseVersionEtag })
 				.catch(error => this._emitError(error))
 
 		this.connection = await connect
@@ -104,6 +105,7 @@ class SyncService {
 		}
 		this.backend = new PollingBackend(this, this.connection)
 		this.version = this.connection.docStateVersion
+		this.baseVersionEtag = this.connection.document.baseVersionEtag
 		this.emit('opened', {
 			...this.connection.state,
 			version: this.version,