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<!DOCTYPE html>
<html>

  <head>
    <base href="." />
    <script type="text/javascript" charset="utf-8">
      window.AngularVersionForThisPlunker = '4.3.3'
    </script>
    <title>angular playground</title>
    <link rel="stylesheet" href="style.css" />
    <script src="https://unpkg.com/core-js@2.4.1/client/shim.min.js"></script>
    <script src="https://unpkg.com/zone.js@0.8.16/dist/zone.js"></script>
    <script src="https://unpkg.com/zone.js@0.8.16/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 */

### Angular Starter Plunker - Typescript

var angularVersion;
if(window.AngularVersionForThisPlunker === 'latest'){
  angularVersion = ''; //picks up latest
}
else {
  angularVersion = '@' + window.AngularVersionForThisPlunker;
}

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'+ angularVersion + '/bundles/core.umd.js',
    '@angular/common': 'npm:@angular/common' + angularVersion + '/bundles/common.umd.js',
    '@angular/compiler': 'npm:@angular/compiler' + angularVersion  + '/bundles/compiler.umd.js',
    '@angular/platform-browser': 'npm:@angular/platform-browser' + angularVersion + '/bundles/platform-browser.umd.js',
    '@angular/platform-browser-dynamic': 'npm:@angular/platform-browser-dynamic' + angularVersion + '/bundles/platform-browser-dynamic.umd.js',
    '@angular/http': 'npm:@angular/http' + angularVersion + '/bundles/http.umd.js',
    '@angular/router': 'npm:@angular/router' + angularVersion +'/bundles/router.umd.js',
    '@angular/forms': 'npm:@angular/forms' + angularVersion + '/bundles/forms.umd.js',
    '@angular/animations': 'npm:@angular/animations' + angularVersion + '/bundles/animations.umd.js',
    '@angular/platform-browser/animations': 'npm:@angular/platform-browser' + angularVersion + '/bundles/platform-browser-animations.umd.js',
    '@angular/animations/browser': 'npm:@angular/animations' + angularVersion + '/bundles/animations-browser.umd.js',
    
    '@angular/core/testing': 'npm:@angular/core' + angularVersion + '/bundles/core-testing.umd.js',
    '@angular/common/testing': 'npm:@angular/common' + angularVersion + '/bundles/common-testing.umd.js',
    '@angular/compiler/testing': 'npm:@angular/compiler' + angularVersion + '/bundles/compiler-testing.umd.js',
    '@angular/platform-browser/testing': 'npm:@angular/platform-browser' + angularVersion + '/bundles/platform-browser-testing.umd.js',
    '@angular/platform-browser-dynamic/testing': 'npm:@angular/platform-browser-dynamic' + angularVersion + '/bundles/platform-browser-dynamic-testing.umd.js',
    '@angular/http/testing': 'npm:@angular/http' + angularVersion + '/bundles/http-testing.umd.js',
    '@angular/router/testing': 'npm:@angular/router' + angularVersion + '/bundles/router-testing.umd.js',
    'tslib': 'npm:tslib@1.6.1',
    'rxjs': 'npm:rxjs@5.5.2',
    'typescript': 'npm:typescript@2.2.1/lib/typescript.js'
  },
  //packages defines our app package
  packages: {
    app: {
      main: './main.ts',
      defaultExtension: 'ts'
    },
    'rxjs': { main: 'index.js', defaultExtension: 'js' },
    'rxjs/operators': {main: 'index.js', 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, VERSION, ChangeDetectionStrategy} from '@angular/core'
import {BrowserModule} from '@angular/platform-browser'
import {ObservableGeneratorService} from './observableGeneratorService.service'
import 'rxjs/Rx';

@Component({
  selector: 'my-app',
  template: `
  <div>
   <label>Ugly:</label>
   <ul>
    <li *ngFor="let uglyNumber of uglyNumbers">
     {{uglyNumber}}
    </li>
   </ul>
   </div>
   <div>
   <label>Good:</label>
   <ul>
    <li *ngFor="let good of goodObservable$ | async">
     {{good}}
    </li>
   </ul>
   </div>
  `,
})
export class App {
  
  private uglyNumbers = [];
  public goodObservable$ : Array<Observable<any>>;
  
  constructor(private observableGeneratorService:ObservableGeneratorService) {
  }
  
  ngOnInit() {
    this.ugly();
    this.good();
  }
  
  ugly() {
    this.observableGeneratorService.getBooleanObservable().subscribe((shouldPresentNumbers) => {
      if(shouldPresentNumbers) {
        this.observableGeneratorService.getNumberObservable().subscribe((val) => {
          this.uglyNumbers.push(val);
        })
      }
    });
  }
  
  good() {
    this.goodObservable$ = this.observableGeneratorService.getBooleanObservable()
    .concatMap((shouldPresentNumbers) => {
      let numbersObservable = shouldPresentNumbers ? this.observableGeneratorService.getNumberObservable() : Observable.empty();
      return numbersObservable;
    }) // concatMap would map "true" to each emitted value (1,2,3,4,5) and creates an observable.
    // Finally it returns: Observable of 1,2,3,4,5
    // this could also be done using ".map(...).combineAll()"
    .toArray(); // turn into an array of observable
  }
}

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

import { Injectable } from '@angular/core';
import { Observable } from "rxjs/Observable";
import { Observer } from "rxjs/Observer";
import { Subject } from "rxjs/Subject";
import 'rxjs/Rx';

@Injectable()
export class ObservableGeneratorService {
  
  getNumberObservable(): Observable<number> {
    return Observable.of(1,2,3,4,5);
  }
  
  getBooleanObservable(): Observable<boolean> {
    return Observable.of(true);
  }
}