How to build example of raising an event from a nested Salesforce component in Angular2?

To use the Component we declare it inside a template and use a custom attribute on the element itself.

const app = {
template: `
<div>
My Counter:
<counter
count="$ctrl.count"
on-update="$ctrl.countUpdated($event);"></counter>
</div>
`,
controller() {
this.count = 2;
this.countUpdated = (event) => {
this.count = event.count;
};
}
};

angular
.module('app')
.component('app', app);