PrfIso<T> class

An isolate-safe preference object that provides type-safe access to SharedPreferences.

Unlike Prf, this implementation does not cache values in memory, making it suitable for use across isolates but requiring disk reads for each access. For non-isolate-safe preferences with caching, use Prf instead.

The class supports various types through adapters, including:

Basic types (String, int, bool, double, Uint8List & more!)
JSON-serializable objects via json factory
Enum values via enumerated factory

You can also create an isolate-safe preference from an existing Prf instance using the .isolated getter:

// Create a cached preference and then get an isolate-safe version
final isolatedUsername = Prf<String>('username').isolated;
await isolatedUsername.set('Alice');
final name = await isolatedUsername.get();

Example:

// Basic type
final username = PrfIso<String>('username');
await username.set('Alice');
final name = await username.get(); // Always reads from disk

// JSON object
final user = PrfIso.json<User>(
  'user',
  fromJson: User.fromJson,
  toJson: (user) => user.toJson(),
);

// Enum value
final theme = PrfIso.enumerated<Theme>(
  'theme',
  values: Theme.values,
  defaultValue: Theme.light,
);

Inheritance

Object
BasePrfObject<T>
PrfIso

Available extensions

PrfOperationExtensions

Constructors

PrfIso.new(String key, {T? defaultValue}): Creates a new isolate-safe preference object with the given key and optional defaultValue.

Properties

adapter → PrfAdapter<T>: The adapter used to convert between the type T and SharedPreferences.
no setteroverride
defaultValue → T?: Optional default value to use when no value exists for key.
finalinherited
hashCode → int: The hash code for this object.
no setterinherited
key → String: The key used to store this preference in SharedPreferences.
finalinherited
runtimeType → Type: A representation of the runtime type of the object.
no setterinherited

Methods

existsOnPrefs() → Future<bool>: Available on BasePrfObject<T>, provided by the PrfOperationExtensions extension
Checks if the key exists in the default PrfService instance.
get() → Future<T?>: Available on BasePrfObject<T>, provided by the PrfOperationExtensions extension
Gets the value from the default PrfService instance.
getOrFallback(T fallback) → Future<T>: Available on BasePrfObject<T>, provided by the PrfOperationExtensions extension
Gets the value or returns the provided fallback if the value is null.
getValue(SharedPreferencesAsync prefs) → Future<T?>: Gets the value from SharedPreferences.
inherited
isNull() → Future<bool>: Available on BasePrfObject<T>, provided by the PrfOperationExtensions extension
Checks if the value is null in the default PrfService instance.
isValueNull(SharedPreferencesAsync prefs) → Future<bool>: Checks if the stored value is null.
inherited
noSuchMethod(Invocation invocation) → dynamic: Invoked when a nonexistent method or property is accessed.
inherited
remove() → Future<void>: Available on BasePrfObject<T>, provided by the PrfOperationExtensions extension
Removes the value from the default PrfService instance.
removeValue(SharedPreferencesAsync prefs) → Future<void>: Removes the value from SharedPreferences.
inherited
set(T value) → Future<void>: Available on BasePrfObject<T>, provided by the PrfOperationExtensions extension
Sets the value using the default PrfService instance.
setValue(SharedPreferencesAsync prefs, T value) → Future<void>: Stores value in SharedPreferences.
inherited
toString() → String: A string representation of this object.
inherited

Operators

operator ==(Object other) → bool: The equality operator.
inherited

Static Methods

customAdapter<T>(String key, {required PrfAdapter<T> adapter, T? defaultValue}) → PrfIso<T>: Creates a new preference using a custom adapter.
enumerated<T extends Enum>(String key, {required List<T> values, T? defaultValue}) → PrfIso<T>: Creates a new preference for an enum value.
json<T>(String key, {required T fromJson(Map<String, dynamic> json), required Map<String, dynamic> toJson(T object), T? defaultValue}) → PrfIso<T>: Creates a new preference for a JSON-serializable object.