Observer pattern implementation in js.

Installation.

``npm
npm i observer-pattern-js
`

Usage example.

`ts
import {IEventEmitter, EventEmitter, IEmitterSubscriber} from "observer-pattern-js";

const emitter: IEventEmitter = new EventEmitter();

const subscriber: IEmitterSubscriber = emitter.subscribe(
'event-name',
(name, surname, age): void => {
console.log(name); // Ikrom.
console.log(surname); // Murodov.
console.log(age); // 18.
},
);

emitter.emit('event-name', 'Ikrom', 'Murodov', 18);

// If you want to unsubscribe from an event you can call the unsubscribe method.
subscriber.unsubscribe();
`

EventEmitter (API).

$3

* Adds the listener function to the end of the listeners array for the event named eventName.
* @param { string } eventName - name of events to subscribe.
* @param { IEmitterCallBack } cb - listener function.
* @public - This method is available to all instances of the EventEmitter class.
* @return { IEmitterSubscriber } - Will return the subscriber object.
* method with which you can unsubscribe from an event.

`ts
import {IEventEmitter, EventEmitter, IEmitterSubscriber} from "observer-pattern-js";

const emitter: IEventEmitter = new EventEmitter();

const subscriber: IEmitterSubscriber = emitter.subscribe('event-name', (...args) => {});
`

$3

* @param { string } eventName.
@param { ... } args - You can pass as many arguments as you like.
* @public - This method is available to all instances of the EventEmitter class.
* @throws Throws an error if no listener has been registered for an event named eventName.
* @return { void } - This method returns nothing.

`ts
import {IEventEmitter, EventEmitter} from "observer-pattern-js";

const emitter: IEventEmitter = new EventEmitter();

emitter.emit('eventName', '...args');
`

$3

* @return { IListeners } - list of listeners
* @public - This method is available to all instances of the EventEmitter class.


`ts
import {IEventEmitter, EventEmitter, IListeners} from "observer-pattern-js";

const emitter: IEventEmitter = new EventEmitter();

const listeners: IListeners = emitter.getListeners();

console.log(listeners);
``