Angular2 Sample Data Initialization

<!DOCTYPE html>
<html>

  <head>
    <base href="." />
    <title>angular2 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/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>
    <script>
      sessionStorage.removeItem('configuration');
    </script>
    <my-app>Initializing Application...</my-app>
  </body>

</html>

/* Styles go here */

### Angular Starter Plunker - Typescript

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, APP_INITIALIZER} from '@angular/core'
import {BrowserModule} from '@angular/platform-browser'
import { HttpModule } from '@angular/http';
import { AppConfig } from './app.config';

@Component({
  selector: 'my-app',
  template: `
    <div>
      <h2>Angular 2 Data Initilization Sample</h2>
      <h3>Sample Key: {{apiKey}}</h3>
      <h5>Key Pulled from <a href="https://jsonplaceholder.typicode.com/posts/1">https://jsonplaceholder.typicode.com/posts/1</a></h5>
      <h5>Stack Overflow: <a href="http://stackoverflow.com/questions/42379540/passing-initialization-data-to-angular-2">http://stackoverflow.com/questions/42379540/passing-initialization-data-to-angular-2</a></h5>
    </div>
  `,
})
export class App {
  
  apiKey:string;
  data:any;
  constructor(private config: AppConfig) {
    this.data = config.data;
    console.log("Data: ", this.data);
    this.apiKey = sessionStorage.getItem('configuration');
  }
}

@NgModule({
  imports: [ BrowserModule, HttpModule ],
  providers: [
    AppConfig,
    {
      provide: APP_INITIALIZER,
      useFactory: (config: AppConfig) => () => {
        return config.load();
      },
      deps: [AppConfig],
      multi: true
    },
  ]
  declarations: [ App ],
  bootstrap: [ App ]
})
export class AppModule {}

import { Inject, Injectable } from '@angular/core';
import { Http } from '@angular/http';
import { Observable } from 'rxjs/Rx';

@Injectable()
export class AppConfig {
  testUrl = 'https://jsonplaceholder.typicode.com/posts/1';
  data:any={};
  constructor(private http: Http) {
  }
  public load() {
    return new Promise((resolve, reject) => {
      this.http.get(this.testUrl)
        .map(res => res.json())
        .catch((error: any): any => {
          console.log('Configuration endpoint could not be read');
          resolve(true);
          return Observable.throw(error.json().error || 'Server error');
        })
        .subscribe((response) => {
          console.log('GOT A RESPONSE:', response);
          this.data = response;
          var cfg = response.title;
          sessionStorage.setItem('configuration', cfg);
          console.log('setting apiKey to ', cfg
          resolve(true);
        });
    });
  }
}