single_item_storage

Description:

single item storage

single_item_storage #
A single item storage abstraction with CRUD operations.
Use it for abstracting storage implementations, for testing, quickly swapping implementations, etc.
This package provides a few implementations, but it's intended to be just a base
for you to implement and provide specific implementation - file, shared preferences or user defaults, etc.
To create your own, implement Storage<E>
Base storage class definition:
abstract class Storage<E> {

Future<E> save(E item);

Future<E?> get();

Future<void> delete();
}
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Provided implementations #
In core module:

MemoryStorage - In-memory volatile implementation
CachedStorage - Wrapper implementation that adds caching capabilities. Use when you have time consuming or performance heavy operations.
ObservedStorage - Wrapper implementation that notifies listeners when the data changes.
StubStorage - Const implementation that won't store any items. Useful for default/null values.

In add-on modules:

SharedPrefsStorage, in package single_item_shared_prefs - SharedPreferences[⬈] implementation of Storage<E>
SecureStorage, in package single_item_secure_storage - FlutterSecureStorage[⬈] implementation of Storage<E>

Example #
CRUD Operations: #
Storage<String> storage = MemoryStorage<String>();

// add/update item
await storage.save('item_1');

// retrieve item
String? myItem = await itemStore.get();

// delete item
await storage.delete();
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Mixing implementations #
You can stack wrapper implementations to add behaviour.
// The following sample will:
// - use SharedPreferences to store data
// - use in-memory cache when possible to save trips to the file system
// - provide data change updates to subscribers to ObservedStorage

ObservedStorage<Item> storage = ObservedStorage(CachedStorage(SharedPrefsStorage(...)));
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