docs(aio): Updated usage of Observables in router guide. Added section for advanced redirects (#18197)

PR Close #18197

aio/content/examples/router/e2e-spec.ts

@@ -12,13 +12,13 @@ describe('Router', () => {
   beforeAll(() => browser.get(''));
 
   function getPageStruct() {
-    const hrefEles = element.all(by.css('my-app a'));
+    const hrefEles = element.all(by.css('my-app > nav a'));
     const crisisDetail = element.all(by.css('my-app > ng-component > ng-component > ng-component > div')).first();
     const heroDetail = element(by.css('my-app > ng-component > div'));
 
     return {
       hrefs: hrefEles,
-      activeHref: element(by.css('my-app a.active')),
+      activeHref: element(by.css('my-app > nav a.active')),
 
       crisisHref: hrefEles.get(0),
       crisisList: element.all(by.css('my-app > ng-component > ng-component li')),

aio/content/examples/router/src/app.css

@@ -15,6 +15,10 @@
   height: 1.6em;
   border-radius: 4px;
 }
+.items li a {
+  display: block;
+  text-decoration: none;
+}
 .items li:hover {
   color: #607D8B;
   background-color: #DDD;

aio/content/examples/router/src/app/app-routing.module.ts

@@ -28,7 +28,7 @@ const appRoutes: Routes = [
     data: { preload: true }
   },
   // #enddocregion preload-v2
-  { path: '',   redirectTo: '/heroes', pathMatch: 'full' },
+  { path: '',   redirectTo: '/superheroes', pathMatch: 'full' },
   { path: '**', component: PageNotFoundComponent }
 ];
 

aio/content/examples/router/src/app/app.component.6.ts

@@ -0,0 +1,23 @@
+// #docplaster
+// #docregion
+import { Component } from '@angular/core';
+
+@Component({
+  selector: 'my-app',
+  // #docregion template
+  template: `
+    <h1 class="title">Angular Router</h1>
+    <nav>
+      <a routerLink="/crisis-center" routerLinkActive="active">Crisis Center</a>
+      <a routerLink="/heroes" routerLinkActive="active">Heroes</a>
+      <a routerLink="/admin" routerLinkActive="active">Admin</a>
+      <a routerLink="/login" routerLinkActive="active">Login</a>
+      <a [routerLink]="[{ outlets: { popup: ['compose'] } }]">Contact</a>
+    </nav>
+    <router-outlet></router-outlet>
+    <router-outlet name="popup"></router-outlet>
+  `
+  // #enddocregion template
+})
+export class AppComponent {
+}

aio/content/examples/router/src/app/app.component.ts

@@ -9,7 +9,7 @@ import { Component } from '@angular/core';
     <h1 class="title">Angular Router</h1>
     <nav>
       <a routerLink="/crisis-center" routerLinkActive="active">Crisis Center</a>
-      <a routerLink="/heroes" routerLinkActive="active">Heroes</a>
+      <a routerLink="/superheroes" routerLinkActive="active">Heroes</a>
       <a routerLink="/admin" routerLinkActive="active">Admin</a>
       <a routerLink="/login" routerLinkActive="active">Login</a>
       <a [routerLink]="[{ outlets: { popup: ['compose'] } }]">Contact</a>

aio/content/examples/router/src/app/can-deactivate-guard.service.1.ts

@@ -1,5 +1,6 @@
 // #docregion
 import { Injectable }           from '@angular/core';
+import { Observable }           from 'rxjs/Observable';
 import { CanDeactivate,
          ActivatedRouteSnapshot,
          RouterStateSnapshot }  from '@angular/router';
@@ -13,7 +14,7 @@ export class CanDeactivateGuard implements CanDeactivate<CrisisDetailComponent>
     component: CrisisDetailComponent,
     route: ActivatedRouteSnapshot,
     state: RouterStateSnapshot
-  ): Promise<boolean> | boolean {
+  ): Observable<boolean> | boolean {
     // Get the Crisis Center ID
     console.log(route.paramMap.get('id'));
 
@@ -25,7 +26,7 @@ export class CanDeactivateGuard implements CanDeactivate<CrisisDetailComponent>
       return true;
     }
     // Otherwise ask the user with the dialog service and return its
-    // promise which resolves to true or false when the user decides
+    // observable which resolves to true or false when the user decides
     return component.dialogService.confirm('Discard changes?');
   }
 }

aio/content/examples/router/src/app/crisis-center/crisis-detail-resolver.service.ts

@@ -1,18 +1,21 @@
 // #docregion
+import 'rxjs/add/operator/map';
+import 'rxjs/add/operator/take';
 import { Injectable }             from '@angular/core';
+import { Observable }             from 'rxjs/Observable';
 import { Router, Resolve, RouterStateSnapshot,
          ActivatedRouteSnapshot } from '@angular/router';
 
-import { Crisis, CrisisService } from './crisis.service';
+import { Crisis, CrisisService }  from './crisis.service';
 
 @Injectable()
 export class CrisisDetailResolver implements Resolve<Crisis> {
   constructor(private cs: CrisisService, private router: Router) {}
 
-  resolve(route: ActivatedRouteSnapshot, state: RouterStateSnapshot): Promise<Crisis> {
+  resolve(route: ActivatedRouteSnapshot, state: RouterStateSnapshot): Observable<Crisis> {
     let id = route.paramMap.get('id');
 
-    return this.cs.getCrisis(id).then(crisis => {
+    return this.cs.getCrisis(id).take(1).map(crisis => {
       if (crisis) {
         return crisis;
       } else { // id not found

aio/content/examples/router/src/app/crisis-center/crisis-detail.component.1.ts

@@ -1,8 +1,9 @@
 // #docplaster
 // #docregion
 import 'rxjs/add/operator/switchMap';
-import { Component, OnInit, HostBinding } from '@angular/core';
+import { Component, OnInit, HostBinding }   from '@angular/core';
 import { ActivatedRoute, Router, ParamMap } from '@angular/router';
+import { Observable }                       from 'rxjs/Observable';
 
 import { slideInDownAnimation }   from '../animations';
 import { Crisis, CrisisService }  from './crisis.service';
@@ -45,7 +46,8 @@ export class CrisisDetailComponent implements OnInit {
   // #docregion ngOnInit
   ngOnInit() {
     this.route.paramMap
-      .switchMap((params: ParamMap) => this.service.getCrisis(params.get('id')))
+      .switchMap((params: ParamMap) =>
+        this.service.getCrisis(params.get('id')))
       .subscribe((crisis: Crisis) => {
         if (crisis) {
           this.editName = crisis.name;
@@ -66,13 +68,13 @@ export class CrisisDetailComponent implements OnInit {
     this.gotoCrises();
   }
 
-  canDeactivate(): Promise<boolean> | boolean {
+  canDeactivate(): Observable<boolean> | boolean {
     // Allow synchronous navigation (`true`) if no crisis or the crisis is unchanged
     if (!this.crisis || this.crisis.name === this.editName) {
       return true;
     }
     // Otherwise ask the user with the dialog service and return its
-    // promise which resolves to true or false when the user decides
+    // observable which resolves to true or false when the user decides
     return this.dialogService.confirm('Discard changes?');
   }
 

aio/content/examples/router/src/app/crisis-center/crisis-detail.component.ts

@@ -2,6 +2,7 @@
 // #docregion
 import { Component, OnInit, HostBinding } from '@angular/core';
 import { ActivatedRoute, Router } from '@angular/router';
+import { Observable } from 'rxjs/Observable';
 
 import { slideInDownAnimation }   from '../animations';
 import { Crisis }         from './crisis.service';
@@ -62,13 +63,13 @@ export class CrisisDetailComponent implements OnInit {
   // #enddocregion cancel-save
 
   // #docregion canDeactivate
-  canDeactivate(): Promise<boolean> | boolean {
+  canDeactivate(): Observable<boolean> | boolean {
     // Allow synchronous navigation (`true`) if no crisis or the crisis is unchanged
     if (!this.crisis || this.crisis.name === this.editName) {
       return true;
     }
     // Otherwise ask the user with the dialog service and return its
-    // promise which resolves to true or false when the user decides
+    // observable which resolves to true or false when the user decides
     return this.dialogService.confirm('Discard changes?');
   }
   // #enddocregion canDeactivate

aio/content/examples/router/src/app/crisis-center/crisis-list.component.1.ts

@@ -1,7 +1,7 @@
-import 'rxjs/add/operator/do';
+
 import 'rxjs/add/operator/switchMap';
-import { Component, OnInit }              from '@angular/core';
-import { ActivatedRoute, Router, ParamMap } from '@angular/router';
+import { Component, OnInit }        from '@angular/core';
+import { ActivatedRoute, ParamMap } from '@angular/router';
 
 import { Crisis, CrisisService } from './crisis.service';
 import { Observable }            from 'rxjs/Observable';
@@ -10,35 +10,34 @@ import { Observable }            from 'rxjs/Observable';
   // #docregion relative-navigation-router-link
   template: `
     <ul class="items">
-      <li *ngFor="let crisis of crises | async">
-        <a [routerLink]="[crisis.id]"
-           [class.selected]="isSelected(crisis)">
-          <span class="badge">{{ crisis.id }}</span>
-          {{ crisis.name }}
+      <li *ngFor="let crisis of crises$ | async"
+        [class.selected]="crisis.id === selectedId">
+        <a [routerLink]="[crisis.id]">
+          <span class="badge">{{ crisis.id }}</span>{{ crisis.name }}
         </a>
       </li>
-    </ul>`
+    </ul>
+
+    <router-outlet></router-outlet>
+    `
   // #enddocregion relative-navigation-router-link
 })
 export class CrisisListComponent implements OnInit {
-  crises: Observable<Crisis[]>;
+  crises$: Observable<Crisis[]>;
   selectedId: number;
 
+
   constructor(
     private service: CrisisService,
-    private route: ActivatedRoute,
-    private router: Router
+    private route: ActivatedRoute
   ) {}
 
+
   ngOnInit() {
-    this.crises = this.route.paramMap
+    this.crises$ = this.route.paramMap
       .switchMap((params: ParamMap) => {
         this.selectedId = +params.get('id');
         return this.service.getCrises();
       });
   }
-
-  isSelected(crisis: Crisis) {
-    return crisis.id === this.selectedId;
-  }
 }

aio/content/examples/router/src/app/crisis-center/crisis-list.component.ts

@@ -1,20 +1,19 @@
 // #docregion
 import 'rxjs/add/operator/switchMap';
-import { Component, OnInit }      from '@angular/core';
-import { ActivatedRoute, Router, ParamMap } from '@angular/router';
-
-import { Observable }            from 'rxjs/Observable';
+import { Component, OnInit }        from '@angular/core';
+import { ActivatedRoute, ParamMap } from '@angular/router';
 
 import { Crisis, CrisisService } from './crisis.service';
+import { Observable }            from 'rxjs/Observable';
 
 @Component({
   template: `
     <ul class="items">
-      <li *ngFor="let crisis of crises | async"
-        (click)="onSelect(crisis)"
-        [class.selected]="isSelected(crisis)">
-          <span class="badge">{{ crisis.id }}</span>
-          {{ crisis.name }}
+      <li *ngFor="let crisis of crises$ | async"
+        [class.selected]="crisis.id === selectedId">
+        <a [routerLink]="[crisis.id]">
+          <span class="badge">{{ crisis.id }}</span>{{ crisis.name }}
+        </a>
       </li>
     </ul>
 
@@ -22,35 +21,21 @@ import { Crisis, CrisisService } from './crisis.service';
   `
 })
 export class CrisisListComponent implements OnInit {
-  crises: Observable<Crisis[]>;
+  crises$: Observable<Crisis[]>;
   selectedId: number;
 
   // #docregion ctor
   constructor(
     private service: CrisisService,
-    private route: ActivatedRoute,
-    private router: Router
+    private route: ActivatedRoute
   ) {}
   // #enddocregion ctor
 
-  isSelected(crisis: Crisis) {
-    return crisis.id === this.selectedId;
-  }
-
   ngOnInit() {
-    this.crises = this.route.paramMap
+    this.crises$ = this.route.paramMap
       .switchMap((params: ParamMap) => {
         this.selectedId = +params.get('id');
         return this.service.getCrises();
       });
   }
-
-  // #docregion onSelect
-  onSelect(crisis: Crisis) {
-    this.selectedId = crisis.id;
-
-    // Navigate with relative link
-    this.router.navigate([crisis.id], { relativeTo: this.route });
-  }
-  // #enddocregion onSelect
 }

aio/content/examples/router/src/app/crisis-center/crisis.service.ts

@@ -1,5 +1,9 @@
 // #docplaster
 // #docregion , mock-crises
+import 'rxjs/add/observable/of';
+import 'rxjs/add/operator/map';
+import { BehaviorSubject } from 'rxjs/BehaviorSubject';
+
 export class Crisis {
   constructor(public id: number, public name: string) { }
 }
@@ -12,20 +16,18 @@ const CRISES = [
 ];
 // #enddocregion mock-crises
 
-let crisesPromise = Promise.resolve(CRISES);
-
 import { Injectable } from '@angular/core';
 
 @Injectable()
 export class CrisisService {
-
   static nextCrisisId = 100;
+  private crises$: BehaviorSubject<Crisis[]> = new BehaviorSubject<Crisis[]>(CRISES);
 
-  getCrises() { return crisesPromise; }
+  getCrises() { return this.crises$; }
 
   getCrisis(id: number | string) {
-    return crisesPromise
-      .then(crises => crises.find(crisis => crisis.id === +id));
+    return this.getCrises()
+      .map(crises => crises.find(crisis => crisis.id === +id));
   }
 
   // #enddocregion
@@ -33,7 +35,8 @@ export class CrisisService {
     name = name.trim();
     if (name) {
       let crisis = new Crisis(CrisisService.nextCrisisId++, name);
-      crisesPromise.then(crises => crises.push(crisis));
+      CRISES.push(crisis);
+      this.crises$.next(CRISES);
     }
   }
   // #docregion

aio/content/examples/router/src/app/dialog.service.ts

@@ -1,5 +1,8 @@
 // #docregion
+import 'rxjs/add/observable/of';
 import { Injectable } from '@angular/core';
+import { Observable } from 'rxjs/Observable';
+
 /**
  * Async modal dialog service
  * DialogService makes this app easier to test by faking this service.
@@ -9,11 +12,11 @@ import { Injectable } from '@angular/core';
 export class DialogService {
   /**
    * Ask user to confirm an action. `message` explains the action and choices.
-   * Returns promise resolving to `true`=confirm or `false`=cancel
+   * Returns observable resolving to `true`=confirm or `false`=cancel
    */
-  confirm(message?: string) {
-    return new Promise<boolean>(resolve => {
-      return resolve(window.confirm(message || 'Is it OK?'));
-    });
+  confirm(message?: string): Observable<boolean> {
+    const confirmation = window.confirm(message || 'Is it OK?');
+
+    return Observable.of(confirmation);
   };
 }

aio/content/examples/router/src/app/heroes/hero-detail.component.1.ts

@@ -4,6 +4,7 @@
 import 'rxjs/add/operator/switchMap';
 // #enddocregion rxjs-operator-import
 import { Component, OnInit } from '@angular/core';
+import { Observable } from 'rxjs/Observable';
 // #docregion imports
 import { Router, ActivatedRoute, ParamMap } from '@angular/router';
 // #enddocregion imports
@@ -13,7 +14,7 @@ import { Hero, HeroService } from './hero.service';
 @Component({
   template: `
   <h2>HEROES</h2>
-  <div *ngIf="hero">
+  <div *ngIf="hero$ | async as hero">
     <h3>"{{ hero.name }}"</h3>
     <div>
       <label>Id: </label>{{ hero.id }}</div>
@@ -28,7 +29,7 @@ import { Hero, HeroService } from './hero.service';
   `
 })
 export class HeroDetailComponent implements OnInit  {
-  hero: Hero;
+  hero$: Observable<Hero>;
 
   // #docregion ctor
   constructor(
@@ -40,10 +41,9 @@ export class HeroDetailComponent implements OnInit  {
 
   // #docregion ngOnInit
   ngOnInit() {
-    this.route.paramMap
+    this.hero$ = this.route.paramMap
       .switchMap((params: ParamMap) =>
-        this.service.getHero(params.get('id')))
-      .subscribe((hero: Hero) => this.hero = hero);
+        this.service.getHero(params.get('id')));
   }
   // #enddocregion ngOnInit
 

aio/content/examples/router/src/app/heroes/hero-detail.component.2.ts

@@ -2,13 +2,14 @@
 // #docregion
 import { Component, OnInit }      from '@angular/core';
 import { ActivatedRoute, Router } from '@angular/router';
+import { Observable }             from 'rxjs/Observable';
 
 import { Hero, HeroService } from './hero.service';
 
 @Component({
   template: `
   <h2>HEROES</h2>
-  <div *ngIf="hero">
+  <div *ngIf="hero$ | async as hero">
     <h3>"{{ hero.name }}"</h3>
     <div>
       <label>Id: </label>{{ hero.id }}</div>
@@ -23,7 +24,7 @@ import { Hero, HeroService } from './hero.service';
   `
 })
 export class HeroDetailComponent implements OnInit  {
-  hero: Hero;
+  hero$: Observable<Hero>;
 
   constructor(
     private route: ActivatedRoute,
@@ -35,8 +36,7 @@ export class HeroDetailComponent implements OnInit  {
   ngOnInit() {
     let id = this.route.snapshot.paramMap.get('id');
 
-    this.service.getHero(id)
-      .then((hero: Hero) => this.hero = hero);
+    this.hero$ = this.service.getHero(id);
   }
   // #enddocregion snapshot
 

aio/content/examples/router/src/app/heroes/hero-detail.component.ts

@@ -4,6 +4,7 @@
 import 'rxjs/add/operator/switchMap';
 // #enddocregion rxjs-operator-import
 import { Component, OnInit, HostBinding } from '@angular/core';
+import { Observable } from 'rxjs/Observable';
 import { Router, ActivatedRoute, ParamMap } from '@angular/router';
 
 import { slideInDownAnimation } from '../animations';
@@ -13,7 +14,7 @@ import { Hero, HeroService }  from './hero.service';
 @Component({
   template: `
   <h2>HEROES</h2>
-  <div *ngIf="hero">
+  <div *ngIf="hero$ | async as hero">
     <h3>"{{ hero.name }}"</h3>
     <div>
       <label>Id: </label>{{ hero.id }}</div>
@@ -22,7 +23,7 @@ import { Hero, HeroService }  from './hero.service';
       <input [(ngModel)]="hero.name" placeholder="name"/>
     </div>
     <p>
-      <button (click)="gotoHeroes()">Back</button>
+      <button (click)="gotoHeroes(hero)">Back</button>
     </p>
   </div>
   `,
@@ -35,7 +36,7 @@ export class HeroDetailComponent implements OnInit {
   @HostBinding('style.position')  position = 'absolute';
 // #enddocregion host-bindings
 
-  hero: Hero;
+  hero$: Observable<Hero>;
 
   // #docregion ctor
   constructor(
@@ -47,16 +48,15 @@ export class HeroDetailComponent implements OnInit {
 
   // #docregion ngOnInit
   ngOnInit() {
-    this.route.paramMap
+    this.hero$ = this.route.paramMap
       .switchMap((params: ParamMap) =>
-        this.service.getHero(params.get('id')))
-      .subscribe((hero: Hero) => this.hero = hero);
+        this.service.getHero(params.get('id')));
   }
   // #enddocregion ngOnInit
 
   // #docregion gotoHeroes
-  gotoHeroes() {
-    let heroId = this.hero ? this.hero.id : null;
+  gotoHeroes(hero: Hero) {
+    let heroId = hero ? hero.id : null;
     // Pass along the hero id if available
     // so that the HeroList component can select that hero.
     // Include a junk 'foo' property for fun.

aio/content/examples/router/src/app/heroes/hero-list.component.1.ts

@@ -3,6 +3,7 @@
 // TODO SOMEDAY: Feature Componetized like HeroCenter
 import { Component, OnInit }   from '@angular/core';
 import { Router }              from '@angular/router';
+import { Observable }          from 'rxjs/Observable';
 
 import { Hero, HeroService }   from './hero.service';
 
@@ -11,9 +12,12 @@ import { Hero, HeroService }   from './hero.service';
   template: `
     <h2>HEROES</h2>
     <ul class="items">
-      <li *ngFor="let hero of heroes | async"
-        (click)="onSelect(hero)">
-        <span class="badge">{{ hero.id }}</span> {{ hero.name }}
+      <li *ngFor="let hero of heroes$ | async">
+        // #docregion nav-to-detail
+        <a [routerLink]="['/hero', hero.id]">
+          <span class="badge">{{ hero.id }}</span>{{ hero.name }}
+        </a>
+        // #enddocregion nav-to-detail
       </li>
     </ul>
 
@@ -22,7 +26,7 @@ import { Hero, HeroService }   from './hero.service';
   // #enddocregion template
 })
 export class HeroListComponent implements OnInit {
-  heroes: Promise<Hero[]>;
+  heroes$: Observable<Hero[]>;
 
   // #docregion ctor
   constructor(
@@ -32,16 +36,8 @@ export class HeroListComponent implements OnInit {
   // #enddocregion ctor
 
   ngOnInit() {
-    this.heroes = this.service.getHeroes();
+    this.heroes$ = this.service.getHeroes();
   }
-
-  // #docregion select
-  onSelect(hero: Hero) {
-    // #docregion nav-to-detail
-    this.router.navigate(['/hero', hero.id]);
-    // #enddocregion nav-to-detail
-  }
-  // #enddocregion select
 }
 // #enddocregion
 

aio/content/examples/router/src/app/heroes/hero-list.component.ts

@@ -7,7 +7,7 @@ import { Observable } from 'rxjs/Observable';
 // #enddocregion rxjs-imports
 import { Component, OnInit } from '@angular/core';
 // #docregion import-router
-import { Router, ActivatedRoute, ParamMap } from '@angular/router';
+import { ActivatedRoute, ParamMap } from '@angular/router';
 // #enddocregion import-router
 
 import { Hero, HeroService }  from './hero.service';
@@ -17,10 +17,11 @@ import { Hero, HeroService }  from './hero.service';
   template: `
     <h2>HEROES</h2>
     <ul class="items">
-      <li *ngFor="let hero of heroes | async"
-        [class.selected]="isSelected(hero)"
-        (click)="onSelect(hero)">
-        <span class="badge">{{ hero.id }}</span> {{ hero.name }}
+      <li *ngFor="let hero of heroes$ | async"
+        [class.selected]="hero.id === selectedId">
+        <a [routerLink]="['/hero', hero.id]">
+          <span class="badge">{{ hero.id }}</span>{{ hero.name }}
+        </a>
       </li>
     </ul>
 
@@ -30,18 +31,17 @@ import { Hero, HeroService }  from './hero.service';
 })
 // #docregion ctor
 export class HeroListComponent implements OnInit {
-  heroes: Observable<Hero[]>;
+  heroes$: Observable<Hero[]>;
 
   private selectedId: number;
 
   constructor(
     private service: HeroService,
-    private route: ActivatedRoute,
-    private router: Router
+    private route: ActivatedRoute
   ) {}
 
   ngOnInit() {
-    this.heroes = this.route.paramMap
+    this.heroes$ = this.route.paramMap
       .switchMap((params: ParamMap) => {
         // (+) before `params.get()` turns the string into a number
         this.selectedId = +params.get('id');
@@ -49,16 +49,6 @@ export class HeroListComponent implements OnInit {
       });
   }
   // #enddocregion ctor
-
-  // #docregion isSelected
-  isSelected(hero: Hero) { return hero.id === this.selectedId; }
-  // #enddocregion isSelected
-
-  // #docregion select
-  onSelect(hero: Hero) {
-    this.router.navigate(['/hero', hero.id]);
-  }
-  // #enddocregion select
 // #docregion ctor
 }
 // #enddocregion

aio/content/examples/router/src/app/heroes/hero.service.ts

@@ -1,11 +1,14 @@
 // #docregion
+import 'rxjs/add/observable/of';
+import 'rxjs/add/operator/map';
 import { Injectable } from '@angular/core';
+import { Observable } from 'rxjs/Observable';
 
 export class Hero {
   constructor(public id: number, public name: string) { }
 }
 
-let HEROES = [
+const HEROES = [
   new Hero(11, 'Mr. Nice'),
   new Hero(12, 'Narco'),
   new Hero(13, 'Bombasto'),
@@ -14,15 +17,13 @@ let HEROES = [
   new Hero(16, 'RubberMan')
 ];
 
-let heroesPromise = Promise.resolve(HEROES);
-
 @Injectable()
 export class HeroService {
-  getHeroes() { return heroesPromise; }
+  getHeroes() { return Observable.of(HEROES); }
 
   getHero(id: number | string) {
-    return heroesPromise
+    return this.getHeroes()
       // (+) before `id` turns the string into a number
-      .then(heroes => heroes.find(hero => hero.id === +id));
+      .map(heroes => heroes.find(hero => hero.id === +id));
   }
 }

aio/content/examples/router/src/app/heroes/heroes-routing.module.1.ts

@@ -0,0 +1,24 @@
+// #docregion
+import { NgModule }             from '@angular/core';
+import { RouterModule, Routes } from '@angular/router';
+
+import { HeroListComponent }    from './hero-list.component';
+import { HeroDetailComponent }  from './hero-detail.component';
+
+const heroesRoutes: Routes = [
+  { path: 'heroes',  component: HeroListComponent },
+// #docregion hero-detail-route
+  { path: 'hero/:id', component: HeroDetailComponent }
+// #enddocregion hero-detail-route
+];
+
+@NgModule({
+  imports: [
+    RouterModule.forChild(heroesRoutes)
+  ],
+  exports: [
+    RouterModule
+  ]
+})
+export class HeroRoutingModule { }
+// #enddocregion

aio/content/examples/router/src/app/heroes/heroes-routing.module.ts

@@ -6,10 +6,10 @@ import { HeroListComponent }    from './hero-list.component';
 import { HeroDetailComponent }  from './hero-detail.component';
 
 const heroesRoutes: Routes = [
-  { path: 'heroes',  component: HeroListComponent },
-// #docregion hero-detail-route
-  { path: 'hero/:id', component: HeroDetailComponent }
-// #enddocregion hero-detail-route
+  { path: 'heroes', redirectTo: '/superheroes' },
+  { path: 'hero/:id', redirectTo: '/superhero/:id' },
+  { path: 'superheroes',  component: HeroListComponent },
+  { path: 'superhero/:id', component: HeroDetailComponent }
 ];
 
 @NgModule({