Flutter Isar

Repository Pattern for Local Data

• Local DataSource wraps all Isar put, get, delete, watch calls
• Repositories orchestrate between remote and local DataSources
• Repositories decide cache-first vs network-first strategy per use case

Offline-First Patterns

• Cache-First: Read from Isar first, fetch from network in background, update Isar on success
• Network-First: Fetch from network, fall back to Isar on failure
• Write-Behind: Write to Isar immediately, sync to server asynchronously (queue pending changes)
• Always show cached data immediately while refreshing in background

Reactive Queries

• Use Isar's watchLazy() or watch() to stream changes to the UI via BLoC
• Wrap Isar watch streams in the repository and expose as Stream<List<DomainModel>>
• Dispose stream subscriptions properly in BLoC close() method

Secure Storage

• Use flutter_secure_storage for sensitive key-value data (tokens, encryption keys)
• Use SharedPreferences ONLY for non-sensitive user preferences (theme, locale, onboarding flags)
• NEVER store passwords, tokens, or secrets in SharedPreferences or plain Isar