Angular2 RC5 Selector and Sub Selector communicating.

<!DOCTYPE html>
<html>

  <head>
    <base href="." />
    <title>angular2 playground</title>
    <link rel="stylesheet" href="style.css" />
    <script src="https://npmcdn.com/zone.js@0.6.12/dist/zone.js"></script>
    <script src="https://npmcdn.com/reflect-metadata@0.1.3/Reflect.js"></script>
    <script src="https://npmcdn.com/systemjs@0.19.31/dist/system.js"></script>
    <script src="https://npmcdn.com/typescript@1.8.10/lib/typescript.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 */

### Angular2 Using ngModel to communicate between Selects

One Select uses object values and upon selection chooses the options available in the second select.

System.config({
  //use typescript for compilation
  transpiler: 'typescript',
  //typescript compiler options
  typescriptOptions: {
    emitDecoratorMetadata: true
  },
  //map tells the System loader where to look for things
  map: {
    app: "./src",
    '@angular': 'https://npmcdn.com/@angular',
    'rxjs': 'https://npmcdn.com/rxjs@5.0.0-beta.6'
  },
  //packages defines our app package
  packages: {
    app: {
      main: './main.ts',
      defaultExtension: 'ts'
    },
    '@angular/core': {
      main: 'bundles/core.umd.js',
      defaultExtension: 'js'
    },
    '@angular/compiler': {
      main: 'bundles/compiler.umd.js',
      defaultExtension: 'js'
    },
    '@angular/common': {
      main: 'bundles/common.umd.js',
      defaultExtension: 'js'
    },
    '@angular/platform-browser-dynamic': {
      main: 'bundles/platform-browser-dynamic.umd.js',
      defaultExtension: 'js'
    },
    '@angular/platform-browser': {
      main: 'bundles/platform-browser.umd.js',
      defaultExtension: 'js'
    },
    '@angular/forms': {
      main: 'index.js',
      defaultExtension: 'js'
    },
    '@angular/router': {
      main: 'index.js',
      defaultExtension: 'js'
    },
    rxjs: {
      defaultExtension: 'js'
    }
  }
});

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

platformBrowserDynamic().bootstrapModule(AppModule)

import { Component, NgModule } from '@angular/core'
import { BrowserModule } from '@angular/platform-browser'
import { FormsModule } from '@angular/forms'

@Component({
	selector: 'my-app',
	template: `
	  <h1>Catagories</h1>
	  <p><select [(ngModel)]="selected">
	    <option value=""></option>
	    <option *ngFor="let datum of data" [ngValue]="datum">{{datum.name}}</option>
    </select>

	  <p><select [(ngModel)]="selected2">
	    <option *ngFor="let val of selected?.value" [ngValue]="val">{{val}}</option>
    </select>
	`
})
class App { 
  private _selected: any;
  set selected (src : any) { 
    this._selected = src; 
    this.selected2 = this._selected.value[0];
  };
  get selected(): any { return this._selected; };
  private selected2: string = "";
  private data: any[] = [
    { "name": "One", "value": ["One_1","One_2","One_3","One_4"] },
    { "name": "Two", "value": ["Two_1","Two_2","Two_3","Two_4"] },
    { "name": "Three", "value": ["Three_1", "Three_2","Three_3"] }
  ];


}

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