Simple ES6 Observer Class

observer.js

class Observer {
	subscribe(subscriber) {
		this.subscribers.push(subscriber);
	}
	publish(event, data) {
		let query = this.subscribers.filter(subscriber => subscriber.event === event);
		if (query.length) query.forEach(subscriber => subscriber.action(data));
	}
	constructor() {
		this.subscribers = [];
	}
}

// Test
const obs = new Observer();

obs.subscribe({
	event: 'event 1',
	action: function(data) {
		console.log('event 1', data);
	}
});

obs.subscribe({
	event: 'event 2',
	action: function(data) {
		console.log('event 2', data);
	}
});

setTimeout(() => {
	obs.publish('event 1', 'Goodbuy');
}, 2000);

setTimeout(() => {
	obs.publish('event 2', 'world');
}, 5000);