Angular 4 Route Directives

<!DOCTYPE html>
<html>

  <head>
    <base href="." />
    <script type="text/javascript" charset="utf-8">
      window.AngularVersionForThisPlunker = 'latest'
    </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/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>

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

platformBrowserDynamic().bootstrapModule(AppModule)

import {Component, OnInit} from '@angular/core';

@Component({
  selector: 'componentC',
  template: `Component C`,
  styles: [
    ':host { display: block; padding: 30px; background-color: yellow }'
  ]
})
export class ComponentC implements OnInit {

  constructor() {
  }

  ngOnInit() {
  }

}

import {Component} from '@angular/core';

@Component({
  selector: 'componentA',
  template: 
     `<componentD></componentD>
      <router-outlet></router-outlet>`,
   styles: [
   ]
})
export class ComponentA { 
}

import {Component, OnInit} from '@angular/core';

@Component({
  selector: 'componentB',
  template: `Component B`,
  styles: [
    ':host { display: block; padding: 30px; background-color: red }'
  ]
})
export class ComponentB implements OnInit {

  constructor() {
  }

  ngOnInit() {

  }

}

import {Component, OnInit} from '@angular/core';

@Component({
  selector: 'componentD',
  template: 
     `<div class="nav" fxLayout="row" fxLayoutAlign=" stretch" fxLayoutGap="5px">
        <a *ngFor="let menuItem of menuItems"
          fxFlex fxLayoutAlign="center center"
          routerLinkActive="active" routerLinkActiveOptions="{ exact: true }" 
          [routerLink]="[menuItem.path]"
          >
          {{menuItem.title}}
        </a>
      </div>`,
   styles: [
     '.nav { padding: 5px; }',
     'a { height: 25px; padding: 0 10px; background-color: rgba(221, 97, 97,0.5);  }',
    '.active { background-color: #ccc; }'
   ]
})
export class ComponentD implements OnInit {
  menuItems = [{
      path: '/b',
      title: 'Go to B'
    },
    {
      path: '/c',
      title: 'Go to C'
    }
  ];

  constructor() {
  }

  ngOnInit() {

  }

}

import { Routes, RouterModule } from '@angular/router';

import { ComponentA } from './componentA';
import { ComponentB } from './componentB';
import { ComponentC } from './componentC';

const routes : Routes = [
  {
    path: '',
    component: ComponentA,
    children: [
      {
        path: 'b',
        component: ComponentB
      },
      {
        path: 'c',
        component: ComponentC
      }
    ]
  }
];

export const AppRouting = RouterModule.forRoot(routes, {useHash: true});

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/common/http': 'npm:@angular/common' + angularVersion + '/bundles/common-http.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/flex-layout': 'npm:@angular/flex-layout@2.0.0-rc.1/bundles/flex-layout.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/common/http/testing': 'npm:@angular/common' + angularVersion + '/bundles/common-http-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',
    'typescript': 'npm:typescript@2.2.1/lib/typescript.js'
  },
  //packages defines our app package
  packages: {
    app: {
      main: './main.ts',
      defaultExtension: 'ts'
    },
    rxjs: {
      defaultExtension: 'js'
    }
  }
});

//our root app component
import { Component, NgModule, VERSION } from '@angular/core';
import { BrowserModule } from '@angular/platform-browser';
import { RouterModule, Router } from '@angular/router';
import { FlexLayoutModule } from '@angular/flex-layout';
import { AppRouting } from './app.routing';
import { ComponentA } from './componentA';
import { ComponentB } from './componentB';
import { ComponentC } from './componentC';
import { ComponentD } from './componentD';

@Component({
  selector: 'my-app',
  template: `
    <div id="wrapper" fxFlexFill fxLayout="column">
      <h2>{{version}}</h2>

      <router-outlet></router-outlet>
    </div> 
  `,
   styles: [
     '#wrapper { text-align: center; }'
   ]
})
export class App {
  version: string;

  constructor(private router: Router) {
    this.version = `Angular v${VERSION.full}`
  }

  ngAfterViewInit() {
    // I don't know how to emulate the initial browser URL here
    this.router.navigate('/b');
  }
}

@NgModule({
  imports: [
    BrowserModule,
    RouterModule,
    FlexLayoutModule,
    AppRouting
  ],
  declarations: [
    App,
    ComponentB,
    ComponentC,
    ComponentA,
    ComponentD
  ],
  bootstrap: [ App ]
})
export class AppModule {}