PrfyJson<T> class

An isolate-safe preference object specialized for storing JSON-serializable objects.

This class provides type-safe access to complex objects stored in SharedPreferences by serializing them to JSON. Unlike PrfJson, it doesn't use in-memory caching, making it suitable for use across multiple isolates where cached values might become stale.

Example:

class Settings {
  final bool darkMode;
  final String locale;

  Settings({required this.darkMode, required this.locale});

  factory Settings.fromJson(Map<String, dynamic> json) => Settings(
    darkMode: json['darkMode'] ?? false,
    locale: json['locale'] ?? 'en_US',
  );

  Map<String, dynamic> toJson() => {
    'darkMode': darkMode,
    'locale': locale,
  };
}

final settingsPreference = PrfyJson<Settings>(
  'app_settings',
  fromJson: Settings.fromJson,
  toJson: (settings) => settings.toJson(),
  defaultValue: Settings(darkMode: false, locale: 'en_US'),
);

await settingsPreference.set(Settings(darkMode: true, locale: 'fr_FR'));
final settings = await settingsPreference.get(); // Always reads from disk

Inheritance

• Object
• BasePrfObject<T>
• PrfyJson

Available extensions

• PrfOperationExtensions

Constructors

PrfyJson.new(String key, {required T fromJson(Map<String, dynamic> json), required Map<String, dynamic> toJson(T object), T? defaultValue})

Creates a new isolate-safe JSON preference.

Properties

adapter → PrfAdapter<T>

Gets the adapter used to convert between the object and its JSON representation.

no setter, override

defaultValue → T?

Optional default value to use when no value exists for key.

final, inherited

hashCode → int

The hash code for this object.

no setter, inherited

key → String

The key used to store this preference in SharedPreferences.

final, inherited

runtimeType → Type

A representation of the runtime type of the object.

no setter, inherited

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