PersistSignalImpl<T> class

Implementation of PersistSignal that persists its value to external storage.

This is the concrete implementation of the PersistSignal interface. PersistSignal automatically saves its value to external storage whenever it changes and loads the initial value from storage when created. It supports both synchronous and asynchronous read/write operations.

See PersistSignal for the public interface and usage examples.

Example:

final theme = PersistSignal(
  initialValue: () => 'light',
  read: () => SharedPreferences.getInstance()
    .then((prefs) => prefs.getString('theme') ?? 'light'),
  write: (value) => SharedPreferences.getInstance()
    .then((prefs) => prefs.setString('theme', value)),
);

theme.value = 'dark'; // Automatically saved to storage
Inheritance
Implemented types
Available extensions

Constructors

PersistSignalImpl({required FutureOr<T> read(), required FutureOr<void> write(T value), T initialValue()?, bool lazy = false, Duration writeDelay = Duration.zero, JoltDebugFn? onDebug})
Creates a persistent signal with the given configuration.

Properties

cachedValue ↔ T?
getter/setter pairinherited
deps ↔ Link?
First dependency link in the chain.
getter/setter pairinherited
depsTail ↔ Link?
Last dependency link in the chain.
getter/setter pairinherited
flags ↔ int
Reactive flags for this node.
getter/setter pairinherited
hashCode → int
The hash code for this object.
no setterinherited
hasInitialized ↔ bool
Whether the signal has been initialized from storage.
getter/setter pairoverride-getter
isDisposed → bool
Whether this node has been disposed.
no setterinherited
listenable → JoltValueListenable<T>

Available on Readonly<T>, provided by the JoltValueListenableExtension extension

Converts this Jolt value to a Flutter ValueListenable.
no setter
notifier → JoltValueNotifier<T>

Available on Readonly<T>, provided by the JoltValueNotifierExtension extension

Converts this Jolt value to a Flutter ValueNotifier.
no setter
peek → T
Returns the current value without establishing a reactive dependency.
no setterinherited
pendingValue ↔ T?
getter/setter pairinherited
read → FutureOr<T> Function()
Function to read the value from storage.
final
runtimeType → Type
A representation of the runtime type of the object.
no setterinherited
stream → Stream<T>

Available on ReadonlyNode<T>, provided by the JoltReadonlyExtension extension

Converts this reactive value to a broadcast stream.
no setter
subs ↔ Link?
First subscriber link in the chain.
getter/setter pairinherited
subsTail ↔ Link?
Last subscriber link in the chain.
getter/setter pairinherited
value ↔ T
Returns the current value and establishes a reactive dependency.
getter/setter pairinherited
write → FutureOr<void> Function(T value)
Function to write the value to storage.
final
writeDelay → Duration
Delay before writing to storage (for debouncing).
final

Methods

dispose() → void
Disposes this node and cleans up resources.
inherited
ensure(FutureOr<void> fn()?) → Future<void>
Ensures the signal is initialized and runs the given function.
override
get() → T
Returns the current value and establishes a reactive dependency.
override
getEnsured() → Future<T>
Gets the value and ensures it's loaded from storage.
override
listen(void onData(T event)?, {Function? onError, void onDone()?, bool? cancelOnError, bool immediately = false}) → StreamSubscription<T>

Available on ReadonlyNode<T>, provided by the JoltReadonlyExtension extension

Creates a stream subscription that listens to changes in this reactive value.
noSuchMethod(Invocation invocation) → dynamic
Invoked when a nonexistent method or property is accessed.
inherited
notify() → void
Manually notifies all subscribers that this signal has changed.
inherited
onDispose() → void
Disposes the signal and cleans up resources.
inherited
readonly() → ReadonlySignal<T>

Available on Signal<T>, provided by the JoltSignalExtension extension

Returns a read-only view of this signal.
set(T value) → T
Sets a new value for the signal and notifies subscribers when it changes.
override
setEnsured(T value, {bool optimistic = false}) → Future<bool>
Sets a value and ensures it's written to storage before completing.
override
toString() → String
A string representation of this object.
inherited
until(bool predicate(T value)) → Future<T>

Available on ReadonlyNode<T>, provided by the JoltReadonlyExtension extension

Waits until the reactive value satisfies a predicate condition.
update(T updater(T value)) → T

Available on WritableNode<T>, provided by the JoltWritableExtension extension

Updates the value using an updater function based on the current value.

Operators

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