Angular 2 for JavaScript old timers (Part II - Services)

<!DOCTYPE html>
<html>
  <head>
    <title>Angular 2 Services - Modern JS</title>
    <script src="https://unpkg.com/core-js/client/shim.min.js"></script>
    <script src="https://unpkg.com/zone.js@0.7.4?main=browser"></script>
    <script src="https://unpkg.com/reflect-metadata@0.1.8"></script>
    <script src="https://unpkg.com/systemjs@0.19.39/dist/system.js"></script>
    <script src="config.js"></script>
    <script>
      System.import('app').then(null, console.error.bind(console));
    </script>
  </head>

  <body>
   <banner-app>Loading...</banner-app>
  </body>

</html>

import {platformBrowserDynamic } from '@angular/platform-browser-dynamic';
import {BannerModule} from './banner.module';

platformBrowserDynamic().bootstrapModule(BannerModule);

import {Component} from '@angular/core';
import {BannerService} from './banner.service';

@Component({
  selector: 'banner-app',
  templateUrl:'app/banner.template.html',
  providers: [BannerService]
})
export class Banner implements OnInit {

  constructor(private _bannerService: BannerService) { }

  message: string;
  isTheBannerVisible: boolean = true;

  
  getMessage() {
    this._bannerService.getMessage().then(message => this.message = message);
  }
  
  ngOnInit() {
    this.getMessage();
  }

  handleClick(event) {
     this.isTheBannerVisible = !this.isTheBannerVisible;
  }

  handleAjaxButtonClick(event) {
     this._bannerService.getMessageViaAjax()
                     .subscribe(
                       message  => this.message = message);
  }
}

import {Injectable} from '@angular/core';
import {Http,Response} from '@angular/http';
import {BANNER_MESSAGE} from './mock-banner';
import {Observable} from 'rxjs/Observable';
import 'rxjs/Rx';

@Injectable()
export class BannerService {
  constructor (private http: Http) {}

  getMessage() { 
     return Promise.resolve(BANNER_MESSAGE);
  }
  
  getMessageViaAjax(): Observable<string> {
    return this.http.get('https://jsonplaceholder.herokuapp.com/posts/1')
                    .map(res => res.json().title);
  }

}

export var BANNER_MESSAGE: string = 'Angular 101!';

 <div>
    <h4><button (click)="handleClick()">Click to {{isTheBannerVisible ? 'hide' : 'show'}} {{message}}</button></h4>
    <div [hidden]="!isTheBannerVisible">{{message}}</div>
    <h4><button (click)="handleAjaxButtonClick()">Click to update message via AJAX</button></h4>
</div>

  System.config({
    transpiler: 'ts',
    typescriptOptions: { 
            // Copy of compiler options in standard tsconfig.json
            "target": "es5",
            "module": "commonjs",
            "moduleResolution": "node",
            "sourceMap": true,
            "emitDecoratorMetadata": true,
            "experimentalDecorators": true,
            "noImplicitAny": true,
            "suppressImplicitAnyIndexErrors": true
    },
    meta: {
          'typescript': {
          "exports": "ts"
           }
    },
    paths: {
      // paths serve as alias
      'npm:': 'https://unpkg.com/'
    },
    // map tells the System loader where to look for things
    map: {
      // our app is within the app folder
      app: 'app',
      // angular bundles
      '@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',
      // other libraries
      'rxjs':                      'npm:rxjs',
      'ts':                        'npm:plugin-typescript@4.0.10/lib/plugin.js',
      'typescript':                'npm:typescript@2.0.3/lib/typescript.js',
    },
    // packages tells the System loader how to load when no filename and/or no extension
    packages: {
      app: {
        main: './main.ts',
        defaultExtension: 'ts'
      },
      rxjs: {
        defaultExtension: 'js'
      }
    }
  });

import { NgModule }      from '@angular/core';
import { BrowserModule } from '@angular/platform-browser';
import { HttpModule } from '@angular/http';
import { Banner } from './banner.component';

@NgModule( {
  imports:      [ BrowserModule, HttpModule],
  declarations: [ Banner ],
  exports:      [ Banner ],
  bootstrap:    [ Banner ]
} )
export class BannerModule {
}