external-event.js

import { component, customEvent, Element } from 'nativeweb';

@component('first-component')
export class FirstComponent extends Element {
    @event() ready = {
        'other-component': this.onReady()
    };

    onReady({ detail }) {
        console.log(detail);
    }
}

@component('other-component')
export class OtherComponent extends Element {
    @customEvent() ready = 'Ready 🚀';

    connected() {
        dispatchEvent(this.ready);
    }
}