Publisher

Installation: If not already installed, add the package with pnpm add @efesto-cloud/publisher.

Use this skill when you need event broadcasting without stored state.

Quick Rule

• Publisher: emit events with notify(...) to current subscribers.
• No state: if you need get/set, use Observable instead.

Procedure

1. Create new PublisherImpl<Args>() with typed tuple args.
2. Register listeners with subscribe(...) and keep the cleanup function.
3. Emit events via notify(...) and cleanup with returned unsubscribe or unsubscribeAll().

Common Mistakes

• Using Publisher as a state container.
• Ignoring returned unsubscribe function.
• Emitting args that do not match the tuple type.

Tiny Example

const bus = new PublisherImpl<[string, number]>();
const off = bus.subscribe((event, code) => console.log(event, code));

bus.notify("saved", 200);
off();

Simplified Interface

type Subscriber<ARGS extends unknown[]> = (...args: ARGS) => void;
type Unsubscribe = () => void;
interface IPublisher<ARGS extends unknown[]> {
    size: number;
    subscribe(s: Subscriber<ARGS>): Unsubscribe;
    unsubscribe(id: number): void;
    notify(...args: ARGS): void;
    unsubscribeAll(): void;
}