Signal<T> class

A base-class that store a value of T and notify the listeners when the value is updated.

You can create a new Signal:

// usign `.signal` extension
final strSignal = "initial value".signal;
final intSignal = 0.signal;
final userSignal = User().signal;
// or usign the constructor class
final strSignal = Signal<String>("initial value");
final intSignal = Signal<int>(0);
final userSignal = Signal<User>(User());

You can get the value:

// usign a `value` getter
print(strSignal.value);
// or using the callable
print(strSignal());
// or using `toString` implicit
print("$intSignal");

You can set a new value:

// usign a `value` setter
strSignal.value = "change value";
// or using the callable
strSignal("change value");

You can use Lifecycle.willUpdate event for before the value is changed, or use Lifecicle.didUpdate event for after the value is changed:

Reactter.on(
  strSignal,
  Lifecycle.willUpdate,
  (signal, _) => print("Previous value: $signal"),
);

Reactter.on(
  strSignal,
  Lifecycle.didUpdate,
  (signal, _) => print("Current value: $signal"),
);

Use update method to notify changes after run a set of instructions:

userSignal.update((user) {
  user.firstname = "Leo";
  user.lastname = "Leon";
});

Use refresh method to force to notify changes.

userSignal.refresh();

If you use flutter, add flutter_reactter package on your dependencies and use its Widgets.

See also:

  • Obj, a base-class that can be used to store a value of T.
Inheritance
Mixed-in types
Available extensions

Constructors

Signal(T initial)

Properties

hashCode → int
The hash code for this object.
no setterinherited
runtimeType → Type
A representation of the runtime type of the object.
no setterinherited
value ↔ T
Returns the value of the signal.
getter/setter pairoverride

Methods

call([T? val]) → T
Gets and/or sets to value like a function This method doesn't allow setting its value to null. If you need to set null as value, use .value = null.
override
dispose() → void
Called when this object is removed
inherited
noSuchMethod(Invocation invocation) → dynamic
Invoked when a nonexistent method or property is accessed.
inherited
refresh() → void
Forces update and notifies to listeners that it did update
inherited
toString() → String
A string representation of this object.
inherited
update(covariant void fnUpdate(T value)) → void
Executes fnUpdate, and notify the listeners about to update.
override
updateAsync(covariant void fnUpdate(dynamic value)) → Future<void>
Executes fnUpdate, and notify the listeners about to update as async way.
override

Operators

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