@byteshift/events

Byteshift Events is a tiny event dispatch & subscription library. It is designed to be incorporated inside your own compiled javascript bundle. The library is entirely self-explanatory. All you need to do is use the emit method from the EventEmitter and give it some arbitrary data (or not). Other parts of the code can subscribe or unsubscribe to- and from emitted events.

See examples below for clarification.

import {EventEmitter, EventSubscriber} from '@byteshift/events';

// Let a class be an event emitter.
class UserRegistration extends EventEmitter
{
    public register(data: any): void
    {
        this.emit('registered', data);
    }
}

// Or just instantiate one.
const emitter = new EventEmitter();

emitter.on('hello', () => console.log('Hello!'));

emitter.emit('hello'); // prints "Hello!" to the console.

Subscribe to the 'register' event:

const userReg = new UserRegistration();


const subscriber: EventSubscriber = userReg.on('registered', (data) => {
    
    // Do something with the data.
    console.log(data);

    // Unsubscribe self, so we won't be called again.
    subscriber.unsubscribe();
});

Subscribe once:

userReg.once('registered', (data) => {
    // I am invoked once.
});

Wait until an event is emitted.

const data = await userReg.when('registered');

---

The on and once methods return an EventSubscription instance, which you can use to unsubscribe from the event if you need to. This takes a lot of the headache away from using regular EventDispatchers in native ECMAScript when you wish to use anonymous or arrow functions to listen to events for a short while.