Blog: Safe Navigation Operator, RxJS and Async Pipes - Part 2

<!DOCTYPE html>
<html>

  <head>
    <base href="." />
    <title>angular2 playground</title>
    <link rel="stylesheet" href="style.css" />
    <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 */

### Angular2 Starter Plunker - Typescript - RC.0

A simple plunker demonstrating Angular2 usage:
- Uses SystemJS + TypeScript to compile on the fly
- Includes binding, directives, http, pipes, and DI usage.

For opening

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': './src',
    
    '@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';

platformBrowserDynamic().bootstrapModule(AppModule)

//our root app component
import {Component, NgModule} from '@angular/core'
import {BrowserModule} from '@angular/platform-browser'
import { Http, HttpModule } from '@angular/http'

import { Observable } from 'rxjs/Observable';

import { PersonDetailComponent } from './personDetail.component';
import 'rxjs/add/operator/map';

@Component({
  selector: 'my-app',
  template: `
    <div>
      Output should be here:
      <person-detail [person]="person | async"></person-detail>
      <hr>
      Debug http call
      <pre>
        {{ (person | async) | json }}
      </pre>
    </div>
  `,
})
export class App {
  person: Observable<any>;
  
  constructor(private http:Http) {
  }
  
  ngOnInit() {
    this.person = this.http
      .get('person.json')
      .map(res => res.json());
  }
}

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

//our root app component
import {Component, NgModule, Input} from '@angular/core'

@Component({
  selector: 'person-detail',
  template: `
    <div>
      Name: {{ person.name }}<br/>
      Twitter: {{ person.twitter.name }}
    </div>
  `,
})
export class PersonDetailComponent {
  
  @Input() person;
  
  constructor() {
  }
  
  ngOnInit() {
    // initialization of the default value
    // HAS TO BE DONE HERE, for whatever reason..
    this.person = { twitter: {} };
  }
}

{
    "name": "Juri Strumpflohner",
    "status": "Currently coding on a screencast",
    "website": {
      "url": "http://juristr.com",
      "name": "juristr.com"
    },
    "twitter": {
      "url": "https://twitter.com/juristr",
      "name": "@juristr"
    }
  }