@rbxts/beacon

Beacon

Beacon is a signal implementation for sending and receiving events.

Signal API

Types

type SignalParams<T> = Parameters<
	T extends unknown[] ? (...args: T) => never : T extends unknown ? (arg: T) => never : () => never
>;

type SignalCallback<T> = (...args: SignalParams<T>) => unknown;

type SignalWait<T> = T extends unknown[] ? LuaTuple<T> : T;

Constructor

const signal = new Signal<T>();

Signal.Connect

public Connect(callback: SignalCallback<T>): Connection<T>

Connects a callback, which will be called each time the signal is fired. The returned connection can be disconnected to stop receiving events.

Signal.Once

public Once(callback: SignalCallback<T>): Connection<T>

Same as Signal.Connect, but disconnects itself after the first time it is triggered.

Signal.Fire

public Fire(...args: SignalParams<T>): void

Fires the signal with the given event. All connected callbacks will receive the event. Internally, this uses task.spawn to fire each callback.

Signal.FireDeferred

public FireDeferred(...args: SignalParams<T>): void

Same as Signal.Fire, except uses task.defer internally.

Signal.Wait

public Wait(): SignalWait<T>

Yields the calling thread until the signal is next fired. Returns the fired event.

Signal.DisconnectAll

public DisconnectAll(): void

Disconnects all connections on the signal.

Signal.Destroy

public Destroy(): void

Alias for Signal.DisconnectAll.

Connection API

Connection.Connected

public Connected: boolean

Indicates if the connection is currently connected.

Connection.Disconnect

public Disconnect(): void

Disconnects the connection.

Connection.Destroy

public Destroy(): void

Alias for Connection.Disconnect.

Example

const messenger = new Signal<string>();

const connection = messenger.Connect((msg) => {
	print(`Got message: ${msg}`);
});

messenger.Fire("Hello world!");
connection.Disconnect();
messenger.Fire("No one will see this");

// The spawned thread will wait indefinitely until the
// signal is fired. If all connections are disconnected
// using signal.Destroy() or signal.DisconnectAll(), then
// the waiting thread will be closed.
task.spawn(() => {
	const msg = messenger.Wait();
	print(`Got message from waiting: ${msg}`);
});
task.wait(2);
messenger.Fire("Hello to the waiting thread");

// Destroying isn't necessary for cleanup, but is nice when
// using signals in OOP environments for quick cleanup.
messenger.Destroy();

Different number of arguments

// No args:
const signal = new Signal<void>();
signal.Connect(() => {});
signal.Fire();

// One arg:
const signal = new Signal<number>();
signal.Connect((n) => print(n));
signal.Fire(32);

// One arg, named (preferred over the above):
const signal = new Signal<[points: number]>();
signal.Connect((points) => print(points));
signal.Fire(64);

// Multiple args:
const signal = new Signal<[msg: string, value: number, cool: boolean]>();
signal.Connect((msg, value, cool) => print(msg, cool, value));
signal.Fire("hello", 10, true);