Angular Tour of Heroes: reprise du chapitre 4 (Services)

angular-tour-of-heroes/src/app/app.component.html

@@ -1,2 +1,3 @@
 <h1>{{title}}</h1>
 <app-heroes></app-heroes>
+<app-messages></app-messages>

angular-tour-of-heroes/src/app/app.module.ts

@@ -5,12 +5,14 @@ import { FormsModule } from '@angular/forms'; // <-- NgModel lives here
 import { AppComponent } from './app.component';
 import { HeroesComponent } from './heroes/heroes.component';
 import { HeroDetailComponent } from './hero-detail/hero-detail.component';
+import { MessagesComponent } from './messages/messages.component';
 
 @NgModule({
   declarations: [
     AppComponent,
     HeroesComponent,
-    HeroDetailComponent
+    HeroDetailComponent,
+    MessagesComponent
   ],
   imports: [
     BrowserModule,

angular-tour-of-heroes/src/app/hero.service.ts

@@ -2,15 +2,18 @@ import { Injectable } from '@angular/core';
 import { Hero } from './hero';
 import { HEROES } from './mock-heroes';
 import { Observable, of } from 'rxjs';
+import { MessageService } from './message.service';
 
 @Injectable({
   providedIn: 'root'
 })
 export class HeroService {
 
-  constructor() { }
+  constructor(private messageService: MessageService) { }
 
   getHeroes(): Observable<Hero[]> {
+    // TODO: send the message _after_ fetching the heroes
+    this.messageService.add('HeroService: fetched heroes.')
     return of(HEROES);
   }
 }

angular-tour-of-heroes/src/app/message.service.spec.ts

@@ -0,0 +1,12 @@
+import { TestBed } from '@angular/core/testing';
+
+import { MessageService } from './message.service';
+
+describe('MessageService', () => {
+  beforeEach(() => TestBed.configureTestingModule({}));
+
+  it('should be created', () => {
+    const service: MessageService = TestBed.get(MessageService);
+    expect(service).toBeTruthy();
+  });
+});

angular-tour-of-heroes/src/app/message.service.ts

@@ -0,0 +1,16 @@
+import { Injectable } from '@angular/core';
+
+@Injectable({
+  providedIn: 'root'
+})
+export class MessageService {
+  messages: string[] = [];
+
+  add(message: string) {
+    this.messages.push(message);
+  }
+
+  clear() {
+    this.messages = [];
+  }
+}

angular-tour-of-heroes/src/app/messages/messages.component.css

@@ -0,0 +1,35 @@
+/* MessagesComponent's private CSS styles */
+h2 {
+  color: red;
+  font-family: Arial, Helvetica, sans-serif;
+  font-weight: lighter;
+}
+body {
+  margin: 2em;
+}
+body, input[text], button {
+  color: crimson;
+  font-family: Cambria, Georgia;
+}
+
+button.clear {
+  font-family: Arial;
+  background-color: #eee;
+  border: none;
+  padding: 5px 10px;
+  border-radius: 4px;
+  cursor: pointer;
+  cursor: hand;
+}
+button:hover {
+  background-color: #cfd8dc;
+}
+button:disabled {
+  background-color: #eee;
+  color: #aaa;
+  cursor: auto;
+}
+button.clear {
+  color: #333;
+  margin-bottom: 12px;
+}

angular-tour-of-heroes/src/app/messages/messages.component.html

@@ -0,0 +1,8 @@
+<div *ngIf="messageService.messages.length">
+
+  <h2>Messages</h2>
+  <button class="clear"
+          (click)="messageService.clear()">clear</button>
+  <div *ngFor='let message of messageService.messages'> {{message}} </div>
+
+</div>

angular-tour-of-heroes/src/app/messages/messages.component.spec.ts

@@ -0,0 +1,25 @@
+import { async, ComponentFixture, TestBed } from '@angular/core/testing';
+
+import { MessagesComponent } from './messages.component';
+
+describe('MessagesComponent', () => {
+  let component: MessagesComponent;
+  let fixture: ComponentFixture<MessagesComponent>;
+
+  beforeEach(async(() => {
+    TestBed.configureTestingModule({
+      declarations: [ MessagesComponent ]
+    })
+    .compileComponents();
+  }));
+
+  beforeEach(() => {
+    fixture = TestBed.createComponent(MessagesComponent);
+    component = fixture.componentInstance;
+    fixture.detectChanges();
+  });
+
+  it('should create', () => {
+    expect(component).toBeTruthy();
+  });
+});

angular-tour-of-heroes/src/app/messages/messages.component.ts

@@ -0,0 +1,16 @@
+import { Component, OnInit } from '@angular/core';
+import { MessageService } from '../message.service';
+
+@Component({
+  selector: 'app-messages',
+  templateUrl: './messages.component.html',
+  styleUrls: ['./messages.component.css']
+})
+export class MessagesComponent implements OnInit {
+
+  constructor(public messageService: MessageService) { }
+
+  ngOnInit() {
+  }
+
+}