Storage

Core defines separate LocalStorage and SecureStorage contracts. Both expose asynchronous string get, set, remove, and contains operations. Core also has BasicMemoryStorage for in-memory typed values; it is useful for transient state and test fixtures, not persistence across process restarts.

Choose a backend based on the data classification and lifecycle. The API contract alone does not make a backend secure: confirm encryption, key storage, backup behavior, and platform guarantees for your threat model. In particular, do not store secrets in ordinary preferences.

Local storage

flueco_shared_preferences adapts shared_preferences to LocalStorage. Its provider requires a SharedPreferences instance registered in the container before bootstrap. Create the plugin instance during app setup:

final preferences = await SharedPreferences.getInstance();
container.singleton<SharedPreferences>((_) => preferences);
providers.add(FluecoSharedPreferencesServiceProvider());

This is a setup fragment; initialize the Flutter binding and plugin prerequisites as required by the app. Values are strings at the Flueco contract boundary, even though the underlying plugin supports additional primitive types.

Secure storage

flueco_hive adapts Hive CE to SecureStorage. Initialize Hive for the target platform before Flueco bootstrap, then register a HiveSecureStorageGetInstanceConfig containing a configured HiveBoxFactory and optional box name. Add FluecoHiveServiceProvider; it initializes its box during provider initialization.

The package's BasicHiveBoxFactory supports encrypted and unencrypted boxes. If using encryption, manage a cryptographically strong key outside source control and follow the platform's secure key-storage practices. The current fromEncryptionKey helper transforms strings by truncating/padding and is not a key-derivation function; review it before use and do not use it as a production key-management strategy. Do not assume that selecting a class named “secure storage” alone establishes an adequate security policy.

Testing and replacement

Depend on the storage contract in application services, not on the plugin-specific box/preferences API. Use an in-memory or fake implementation for unit tests, then add integration tests for persistence and platform behavior. LocalStorage and SecureStorage are separate contracts, so keep consumers typed to the distinction they require.

See the flueco_core, flueco_shared_preferences, and flueco_hive references for the exported APIs.