emit-kit v1.0.4

emit-kit

A wrapper on top of eventemitter3 with the convenient abstractions of event-kit.

Usage

import {Emitter} from 'emit-kit';

// The event emitter
class Superhero {
  constructor() {
    this._emitter = new Emitter();
  }

  onFlight(callback) {
    return this._emitter.on('flight', callback);
  }

  fly(time) {
    this._emitter.emit('flight', time);
  }
}

// The subscriber
class Supervillain {
  plotToKill(superhero) {
    this.surveillance = superhero.onFlight(time => console.log(time));
  }

  giveUp() {
    this.surveillance.cancel();
  }
}

API

Emitter

• .on(event, callback, context)

  • Subscribes a callback to an event.
  • event - String. The name of the event.
  • callback - Function. Invoked with arguments
  • context (optional) - Object. The this object to bind to the callback.

• .once(event, callback, context)

  • Same as .on() but with a one-time callback.

• .emit(event, ...args)

  • Invokes all callbacks subscribed to event.
  • event - String. The name of the event.
  • args - Arguments to be passed to the callbacks.

• .clear(event)

  • If event is given, removes only the callbacks subscribed to event. Else removes all callbacks.
  • event (optional) - String. The name of the event.

• .count(event)

  • If event is given, returns the number of callbacks registered to event. Else returns the total number of callbacks.

Subscription

• .cancel()
  • Unsubscribes from the event emitter.

Subscriptions

• .add(...subs)

  • Groups subs together so that they can later be cancelled as a group.

• .cancel()

  • Calls cancel asynchronously on all associated subs. Returns a promise that fulfills upon completion.

• .cancelSync()

  • Calls cancel synchronously on all associated subs.