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@ue-too/board / AsyncObservable

Class: AsyncObservable<T> ​

Defined in: packages/board/src/utils/observable.ts:113

Asynchronous Observable implementation that notifies observers via microtasks.

Remarks ​

This Observable uses queueMicrotask to defer observer notifications, ensuring they execute after the current execution context completes but before the next task. This prevents recursive notification issues and allows the notifier to complete before observers run.

Use AsyncObservable when:

  • You want to prevent recursion issues in notifications
  • Observer execution should not block the notifier
  • You need guaranteed async behavior

Example ​

typescript
const observable = new AsyncObservable<[string]>();

observable.subscribe((message) => {
  console.log('Observer received:', message);
});

console.log('Before notify');
observable.notify('Hello');
console.log('After notify');

// Output:
// Before notify
// After notify
// Observer received: Hello

See ​

SynchronousObservable for synchronous notifications

Type Parameters ​

T ​

T extends any[]

Tuple type of data emitted to observers

Implements ​

Constructors ​

Constructor ​

new AsyncObservable<T>(): AsyncObservable<T>

Returns ​

AsyncObservable<T>

Methods ​

notify() ​

notify(...data): void

Defined in: packages/board/src/utils/observable.ts:165

Notifies all observers with the provided data asynchronously.

Parameters ​

data ​

...T

The data to pass to all observers

Returns ​

void

Remarks ​

Each observer is called via queueMicrotask, ensuring async execution. This method returns immediately; observers run later in the event loop.

Implementation of ​

Observable.notify

subscribe() ​

subscribe(observer, options?): () => void

Defined in: packages/board/src/utils/observable.ts:127

Subscribes an observer to receive notifications.

Parameters ​

observer ​

Observer<T>

The callback function to be notified

options? ​

SubscriptionOptions

Optional subscription options including AbortSignal

Returns ​

Unsubscribe function to remove this observer

(): void

Returns ​

void

Remarks ​

If an AbortSignal is provided and is already aborted, the observer is not added and the returned unsubscribe function is a no-op.

Implementation of ​

Observable.subscribe