sub-events v1.9.0

Strongly-Typed Events

Lightweight, strongly-typed events, with monitored subscriptions.

• Documentation: API + WiKi.
• Compatible with all existing events - see Extras.

Install

npm i sub-events

Usage

• On event-provider side:

import {SubEvent} from 'sub-events';

// creating a strongly-typed event: 
const e: SubEvent<string> = new SubEvent();

// triggering the event when needed:
e.emit('hello');

API: SubEvent, emit

• On event-consumer side:

// subscribing to the event:
const sub = e.subscribe((data: string) => {
  // data = 'hello'
});

// cancel the subscription when no longer needed:
sub.cancel();

API: Subscription, subscribe, cancel

Monitoring Subscriptions

Class SubEventCount extends SubEvent with event onCount, to observe the number of subscriptions:

import {SubEventCount, ISubCountChange} from 'sub-events';

// creating a strongly-typed event:
const e: SubEventCount<string> = new SubEventCount();

e.onCount.subscribe((info: ISubCountChange) => {
    // number of subscriptions has changed;
    // info = {newCount, prevCount} 
});

// any subscription will trigger event onCount:
const sub = e.subscribe(data => {});

// cancelling a subscription will trigger onCount:
sub.cancel();

API: SubEventCount, onCount

Browser

When including directly from HTML, you can access all types under subEvents namespace:

<script src="./node_modules/sub-events/dist"></script>
<script>
    const e = new subEvents.SubEvent();
    e.subscribe(data => {
        // data received
    });
</script>

Note that pre-built script includes only the core library, without the Extras, which you can bundle yourself as needed.