Component events with EventEmitter and "Output" in Angular 2

<!DOCTYPE html>
<html>

  <head>
    <base href="." />
    <title>angular2 playground</title>
    <link rel="stylesheet" href="style.css" />
    
    <link rel="stylesheet" href="https://maxcdn.bootstrapcdn.com/bootstrap/3.3.7/css/bootstrap.min.css" integrity="sha384-BVYiiSIFeK1dGmJRAkycuHAHRg32OmUcww7on3RYdg4Va+PmSTsz/K68vbdEjh4u" crossorigin="anonymous">

<!-- Optional theme -->
<link rel="stylesheet" href="https://maxcdn.bootstrapcdn.com/bootstrap/3.3.7/css/bootstrap-theme.min.css" integrity="sha384-rHyoN1iRsVXV4nD0JutlnGaslCJuC7uwjduW9SVrLvRYooPp2bWYgmgJQIXwl/Sp" crossorigin="anonymous">

<!-- Latest compiled and minified JavaScript -->
<script src="https://maxcdn.bootstrapcdn.com/bootstrap/3.3.7/js/bootstrap.min.js" integrity="sha384-Tc5IQib027qvyjSMfHjOMaLkfuWVxZxUPnCJA7l2mCWNIpG9mGCD8wGNIcPD7Txa" crossorigin="anonymous"></script>
    
    <script src="https://unpkg.com/core-js@2.4.1/client/shim.min.js"></script>
    <script src="https://unpkg.com/zone.js/dist/zone.js"></script>
    <script src="https://unpkg.com/zone.js/dist/long-stack-trace-zone.js"></script>
    <script src="https://unpkg.com/reflect-metadata@0.1.3/Reflect.js"></script>
    <script src="https://unpkg.com/systemjs@0.19.31/dist/system.js"></script>
    <script src="config.js"></script>
    <script>
    System.import('app')
      .catch(console.error.bind(console));
  </script>
  </head>

  <body>
    <my-app>
    loading...
  </my-app>
  </body>

</html>

/* Styles go here */

.app {
      display: block;
      text-align: center;
      padding: 25px;
      background: #f5f5f5;
    }

System.config({
  //use typescript for compilation
  transpiler: 'typescript',
  //typescript compiler options
  typescriptOptions: {
    emitDecoratorMetadata: true
  },
  paths: {
    'npm:': 'https://unpkg.com/'
  },
  //map tells the System loader where to look for things
  map: {
    
    'app': './app',
    
    '@angular/core': 'npm:@angular/core/bundles/core.umd.js',
    '@angular/common': 'npm:@angular/common/bundles/common.umd.js',
    '@angular/compiler': 'npm:@angular/compiler/bundles/compiler.umd.js',
    '@angular/platform-browser': 'npm:@angular/platform-browser/bundles/platform-browser.umd.js',
    '@angular/platform-browser-dynamic': 'npm:@angular/platform-browser-dynamic/bundles/platform-browser-dynamic.umd.js',
    '@angular/http': 'npm:@angular/http/bundles/http.umd.js',
    '@angular/router': 'npm:@angular/router/bundles/router.umd.js',
    '@angular/forms': 'npm:@angular/forms/bundles/forms.umd.js',
    
    '@angular/core/testing': 'npm:@angular/core/bundles/core-testing.umd.js',
    '@angular/common/testing': 'npm:@angular/common/bundles/common-testing.umd.js',
    '@angular/compiler/testing': 'npm:@angular/compiler/bundles/compiler-testing.umd.js',
    '@angular/platform-browser/testing': 'npm:@angular/platform-browser/bundles/platform-browser-testing.umd.js',
    '@angular/platform-browser-dynamic/testing': 'npm:@angular/platform-browser-dynamic/bundles/platform-browser-dynamic-testing.umd.js',
    '@angular/http/testing': 'npm:@angular/http/bundles/http-testing.umd.js',
    '@angular/router/testing': 'npm:@angular/router/bundles/router-testing.umd.js',
    
    'rxjs': 'npm:rxjs',
    'typescript': 'npm:typescript@2.0.2/lib/typescript.js'
  },
  //packages defines our app package
  packages: {
    app: {
      main: './main.ts',
      defaultExtension: 'ts'
    },
    rxjs: {
      defaultExtension: 'js'
    }
  }
});

//main entry point
import {platformBrowserDynamic} from '@angular/platform-browser-dynamic';
import {AppModule} from './app.module';

platformBrowserDynamic().bootstrapModule(AppModule)

import {Component} from '@angular/core';

@Component({
  selector: 'my-app',
  template: `
    <div class="app">
      <counter [init]="myValue" (change)="myValueChange($event);"></counter>
    </div>
  `
})
export class AppComponent {
  public myValue:number = 2;
  
  myValueChange($event) {
    console.log($event);
  }
}

import {Component, Input, Output, EventEmitter} from '@angular/core';

@Component({
  selector: 'counter',
  styles: [`
    .numric-value {
      text-align: center;
    }
  `],
  template: `
  <div class="row">
    <div class="col-xs-6 col-xs-offset-3">
      <div class="input-group">
        <span class="input-group-btn">
          <button class="btn btn-primary" type="button" (click)="decrement();">
            <span class="glyphicon glyphicon-minus" aria-hidden="true"></span>
          </button>
        </span>
        <input type="text" class="form-control numric-value" [value]="counterValue">
        <span class="input-group-btn">
          <button class="btn btn-primary" type="button" (click)="increment();">
            <span class="glyphicon glyphicon-plus" aria-hidden="true"></span>
          </button>
        </span>
      </div>
    </div>
  </div>
  `
})
export class CounterComponent {
  @Input('init') counterValue = 0;
  @Output('change') counterChange = new EventEmitter();
  increment() {
    this.counterValue++;
    this.counterChange.emit({
      value: this.counterValue
    })
  }
  decrement() {
    this.counterValue--;
    this.counterChange.emit({
      value: this.counterValue
    })
  }
}

import {Component, NgModule} from '@angular/core'
import {BrowserModule} from '@angular/platform-browser'
import { FormsModule }         from '@angular/forms';
import {AppComponent} from './app.component';
import {CounterComponent} from './counter.component';

@NgModule({
  imports: [ BrowserModule, FormsModule ],
  declarations: [ AppComponent, CounterComponent ],
  bootstrap: [ AppComponent ]
})
export class AppModule {}