moai-platform-firestore

Enable offline persistence by calling initializeFirestore with persistentLocalCache, optionally adding persistentMultipleTabManager for multi-tab support and CACHE_SIZE_UNLIMITED for cache size. On Flutter, set persistenceEnabled to true in the Firestore settings.

Write role-based Security Rules by storing roles in custom claims via the Admin SDK or in member documents, then checking request.auth.token or using get() on membership documents inside match blocks. Test rules with the Firebase emulator and @firebase/rules-unit-testing.

Transactions read current document values and retry automatically on conflicts, making them suitable for operations dependent on existing data. Batch writes execute up to 500 operations atomically without reads, making them better for bulk updates.

Yes, Firestore onSnapshot listeners work offline by serving data from the local cache. Set includeMetadataChanges to true to detect hasPendingWrites and fromCache flags, which indicate whether data is synced or still local.

Transactions fail when a read occurs after a write, when documents change during execution causing aborted errors, or when preconditions fail. Ensure all transaction.get calls happen before any writes and handle aborted errors with retries.

Both batch writes and transactions support a maximum of 500 documents per operation. For larger updates, split operations into chunks of 500 and commit each batch sequentially.