shared_preferences_typed

Description:

shared preferences typed

Typed Shared Preferences #

A type-safe wrapper around shared_preferences, inspired by ts-localstorage.
Why? #

Dart compiler now prevents you from writing a bool to an int key
You can organize everything related to [SharedPreferences] in one file, not just the string keys
You don't need to call SharedPreferences.getInstance() anywhere anymore

Usage #

You create a PrefKey or a PrefKeyNullable, pass a string as a key and a default value that's returned when the value doesn't exist in the SharedPreferences.
In case of PrefKeyNullable, the default value is still required to guarantee type safety, but it's not actually used anywhere

Check test/shared_preferences_typed_test.dart for a more detailed example, here are the most common use cases:
Basic example (non-nullable) #
/// Description
const key = PrefKey("some_key", true);

final valueBefore = await key.read(); // -> true (default value)
await key.write(false); // -> Value is now false
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Basic example (nullable) #
/// Description
const key = PrefKeyNullable("some_key", true);

final valueBefore = await key.read(); // -> null
await key.write(false); // -> Value is now false
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Existing SharedPreferences instance (non-nullable) #
final prefs = await SharedPreferences.instance();

/// Description
const key = PrefKey("some_key", true);

final valueBefore = await key.readSync(prefs); // -> true (default value)
await key.write(false); // -> Value is now false
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Existing SharedPreferences instance (nullable) #
final prefs = await SharedPreferences.instance();

/// Description
const key = PrefKeyNullable("some_key", true);

final valueBefore = await key.readSync(prefs); // -> null
await key.writeSync(false, prefs); // -> Value is now false
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Additional information #

Using an existing SharedPreferences instance has no performance gain if you don't also use it elsewhere. However, the sync methods have benefits when you really can't have await somewhere.