Shows how to write a zippy component in pure ES6

zippy.js

// following https://github.com/angular/angular/blob/2.0.0-beta.6/modules/playground/src/zippy_component/zippy.ts

import {Component, EventEmitter, Input, Output} from 'angular2/core';
import {ObservableWrapper} from 'angular2/src/facade/async';

export Zippy;

Zippy.annotations = [
  new Component({
    selector: 'zippy', 
    templateUrl: 'zippy.html'
  })
];

Reflect.decorate([Input()], Zippy.prototype, 'title', '');
Reflect.decorate([Output()], Zippy.prototype, 'open', new EventEmitter());
Reflect.decorate([Output()], Zippy.prototype, 'close', new EventEmitter());

function Zippy () {
  this.visible = true;
  this.toggle = toggle;
  
  //
  
  function toggle() {
    this.visible = !this.visible;
    if (this.visible) {
      ObservableWrapper.callEmit(this.open, null);
    } else {
      ObservableWrapper.callEmit(this.close, null);
    }
  }
}