feat(challenge1): modernization

Author: tomalaforge

apps/angular/1-projection/src/app/component/city-card/city-card.component.ts

@@ -1,12 +1,9 @@
-import { Component, OnInit } from '@angular/core';
+import { ChangeDetectionStrategy, Component } from '@angular/core';
 
 @Component({
   selector: 'app-city-card',
   template: 'TODO City',
   imports: [],
+  changeDetection: ChangeDetectionStrategy.OnPush,
 })
-export class CityCardComponent implements OnInit {
-  constructor() {}
-
-  ngOnInit(): void {}
-}
+export class CityCardComponent {}

apps/angular/1-projection/src/app/component/student-card/student-card.component.ts

@@ -1,17 +1,21 @@
-import { Component, OnInit } from '@angular/core';
+import {
+  ChangeDetectionStrategy,
+  Component,
+  inject,
+  OnInit,
+} from '@angular/core';
 import { FakeHttpService } from '../../data-access/fake-http.service';
 import { StudentStore } from '../../data-access/student.store';
 import { CardType } from '../../model/card.model';
-import { Student } from '../../model/student.model';
 import { CardComponent } from '../../ui/card/card.component';
 
 @Component({
   selector: 'app-student-card',
   template: `
     <app-card
-      [list]="students"
+      [list]="students()"
       [type]="cardType"
-      customClass="bg-light-green"></app-card>
+      customClass="bg-light-green" />
   `,
   styles: [
     `
@@ -21,19 +25,16 @@ import { CardComponent } from '../../ui/card/card.component';
     `,
   ],
   imports: [CardComponent],
+  changeDetection: ChangeDetectionStrategy.OnPush,
 })
 export class StudentCardComponent implements OnInit {
-  students: Student[] = [];
-  cardType = CardType.STUDENT;
+  private http = inject(FakeHttpService);
+  private store = inject(StudentStore);
 
-  constructor(
-    private http: FakeHttpService,
-    private store: StudentStore,
-  ) {}
+  students = this.store.students;
+  cardType = CardType.STUDENT;
 
   ngOnInit(): void {
     this.http.fetchStudents$.subscribe((s) => this.store.addAll(s));
-
-    this.store.students$.subscribe((s) => (this.students = s));
   }
 }

apps/angular/1-projection/src/app/component/teacher-card/teacher-card.component.ts

@@ -1,15 +1,14 @@
-import { Component, OnInit } from '@angular/core';
+import { Component, inject, OnInit } from '@angular/core';
 import { FakeHttpService } from '../../data-access/fake-http.service';
 import { TeacherStore } from '../../data-access/teacher.store';
 import { CardType } from '../../model/card.model';
-import { Teacher } from '../../model/teacher.model';
 import { CardComponent } from '../../ui/card/card.component';
 
 @Component({
   selector: 'app-teacher-card',
   template: `
     <app-card
-      [list]="teachers"
+      [list]="teachers()"
       [type]="cardType"
       customClass="bg-light-red"></app-card>
   `,
@@ -23,17 +22,13 @@ import { CardComponent } from '../../ui/card/card.component';
   imports: [CardComponent],
 })
 export class TeacherCardComponent implements OnInit {
-  teachers: Teacher[] = [];
-  cardType = CardType.TEACHER;
+  private http = inject(FakeHttpService);
+  private store = inject(TeacherStore);
 
-  constructor(
-    private http: FakeHttpService,
-    private store: TeacherStore,
-  ) {}
+  teachers = this.store.teachers;
+  cardType = CardType.TEACHER;
 
   ngOnInit(): void {
     this.http.fetchTeachers$.subscribe((t) => this.store.addAll(t));
-
-    this.store.teachers$.subscribe((t) => (this.teachers = t));
   }
 }

apps/angular/1-projection/src/app/data-access/city.store.ts

@@ -1,23 +1,21 @@
-import { Injectable } from '@angular/core';
-import { BehaviorSubject } from 'rxjs';
+import { Injectable, signal } from '@angular/core';
 import { City } from '../model/city.model';
 
 @Injectable({
   providedIn: 'root',
 })
 export class CityStore {
-  private cities = new BehaviorSubject<City[]>([]);
-  cities$ = this.cities.asObservable();
+  private cities = signal<City[]>([]);
 
   addAll(cities: City[]) {
-    this.cities.next(cities);
+    this.cities.set(cities);
   }
 
   addOne(student: City) {
-    this.cities.next([...this.cities.value, student]);
+    this.cities.set([...this.cities(), student]);
   }
 
   deleteOne(id: number) {
-    this.cities.next(this.cities.value.filter((s) => s.id !== id));
+    this.cities.set(this.cities().filter((s) => s.id !== id));
   }
 }

apps/angular/1-projection/src/app/data-access/student.store.ts

@@ -1,23 +1,21 @@
-import { Injectable } from '@angular/core';
-import { BehaviorSubject } from 'rxjs';
+import { Injectable, signal } from '@angular/core';
 import { Student } from '../model/student.model';
 
 @Injectable({
   providedIn: 'root',
 })
 export class StudentStore {
-  private students = new BehaviorSubject<Student[]>([]);
-  students$ = this.students.asObservable();
+  public students = signal<Student[]>([]);
 
   addAll(students: Student[]) {
-    this.students.next(students);
+    this.students.set(students);
   }
 
   addOne(student: Student) {
-    this.students.next([...this.students.value, student]);
+    this.students.set([...this.students(), student]);
   }
 
   deleteOne(id: number) {
-    this.students.next(this.students.value.filter((s) => s.id !== id));
+    this.students.set(this.students().filter((s) => s.id !== id));
   }
 }

apps/angular/1-projection/src/app/data-access/teacher.store.ts

@@ -1,23 +1,21 @@
-import { Injectable } from '@angular/core';
-import { BehaviorSubject } from 'rxjs';
+import { Injectable, signal } from '@angular/core';
 import { Teacher } from '../model/teacher.model';
 
 @Injectable({
   providedIn: 'root',
 })
 export class TeacherStore {
-  private teachers = new BehaviorSubject<Teacher[]>([]);
-  teachers$ = this.teachers.asObservable();
+  public teachers = signal<Teacher[]>([]);
 
   addAll(teachers: Teacher[]) {
-    this.teachers.next(teachers);
+    this.teachers.set(teachers);
   }
 
   addOne(teacher: Teacher) {
-    this.teachers.next([...this.teachers.value, teacher]);
+    this.teachers.set([...this.teachers(), teacher]);
   }
 
   deleteOne(id: number) {
-    this.teachers.next(this.teachers.value.filter((t) => t.id !== id));
+    this.teachers.set(this.teachers().filter((t) => t.id !== id));
   }
 }

apps/angular/1-projection/src/app/ui/card/card.component.ts

@@ -1,5 +1,5 @@
-import { NgFor, NgIf } from '@angular/common';
-import { Component, Input } from '@angular/core';
+import { NgOptimizedImage } from '@angular/common';
+import { Component, inject, input } from '@angular/core';
 import { randStudent, randTeacher } from '../../data-access/fake-http.service';
 import { StudentStore } from '../../data-access/student.store';
 import { TeacherStore } from '../../data-access/teacher.store';
@@ -11,22 +11,21 @@ import { ListItemComponent } from '../list-item/list-item.component';
   template: `
     <div
       class="flex w-fit flex-col gap-3 rounded-md border-2 border-black p-4"
-      [class]="customClass">
-      <img
-        *ngIf="type === CardType.TEACHER"
-        src="assets/img/teacher.png"
-        width="200px" />
-      <img
-        *ngIf="type === CardType.STUDENT"
-        src="assets/img/student.webp"
-        width="200px" />
+      [class]="customClass()">
+      @if (type() === CardType.TEACHER) {
+        <img ngSrc="assets/img/teacher.png" width="200" height="200" />
+      }
+      @if (type() === CardType.STUDENT) {
+        <img ngSrc="assets/img/student.webp" width="200" height="200" />
+      }
 
       <section>
-        <app-list-item
-          *ngFor="let item of list"
-          [name]="item.firstName"
-          [id]="item.id"
-          [type]="type"></app-list-item>
+        @for (item of list(); track item) {
+          <app-list-item
+            [name]="item.firstName"
+            [id]="item.id"
+            [type]="type()"></app-list-item>
+        }
       </section>
 
       <button
@@ -36,24 +35,23 @@ import { ListItemComponent } from '../list-item/list-item.component';
       </button>
     </div>
   `,
-  imports: [NgIf, NgFor, ListItemComponent],
+  imports: [ListItemComponent, NgOptimizedImage],
 })
 export class CardComponent {
-  @Input() list: any[] | null = null;
-  @Input() type!: CardType;
-  @Input() customClass = '';
+  private teacherStore = inject(TeacherStore);
+  private studentStore = inject(StudentStore);
 
-  CardType = CardType;
+  readonly list = input<any[] | null>(null);
+  readonly type = input.required<CardType>();
+  readonly customClass = input('');
 
-  constructor(
-    private teacherStore: TeacherStore,
-    private studentStore: StudentStore,
-  ) {}
+  CardType = CardType;
 
   addNewItem() {
-    if (this.type === CardType.TEACHER) {
+    const type = this.type();
+    if (type === CardType.TEACHER) {
       this.teacherStore.addOne(randTeacher());
-    } else if (this.type === CardType.STUDENT) {
+    } else if (type === CardType.STUDENT) {
       this.studentStore.addOne(randStudent());
     }
   }

apps/angular/1-projection/src/app/ui/list-item/list-item.component.ts

@@ -1,4 +1,9 @@
-import { Component, Input } from '@angular/core';
+import {
+  ChangeDetectionStrategy,
+  Component,
+  inject,
+  input,
+} from '@angular/core';
 import { StudentStore } from '../../data-access/student.store';
 import { TeacherStore } from '../../data-access/teacher.store';
 import { CardType } from '../../model/card.model';
@@ -7,28 +12,28 @@ import { CardType } from '../../model/card.model';
   selector: 'app-list-item',
   template: `
     <div class="border-grey-300 flex justify-between border px-2 py-1">
-      {{ name }}
-      <button (click)="delete(id)">
+      {{ name() }}
+      <button (click)="delete(id())">
         <img class="h-5" src="assets/svg/trash.svg" />
       </button>
     </div>
   `,
   standalone: true,
+  changeDetection: ChangeDetectionStrategy.OnPush,
 })
 export class ListItemComponent {
-  @Input() id!: number;
-  @Input() name!: string;
-  @Input() type!: CardType;
+  private teacherStore = inject(TeacherStore);
+  private studentStore = inject(StudentStore);
 
-  constructor(
-    private teacherStore: TeacherStore,
-    private studentStore: StudentStore,
-  ) {}
+  readonly id = input.required<number>();
+  readonly name = input.required<string>();
+  readonly type = input.required<CardType>();
 
   delete(id: number) {
-    if (this.type === CardType.TEACHER) {
+    const type = this.type();
+    if (type === CardType.TEACHER) {
       this.teacherStore.deleteOne(id);
-    } else if (this.type === CardType.STUDENT) {
+    } else if (type === CardType.STUDENT) {
       this.studentStore.deleteOne(id);
     }
   }

docs/src/content/docs/challenges/angular/1-projection.md

@@ -41,12 +41,11 @@ While the application works, the developer experience is far from being optimal.
 ## Constraints
 
 - You <b>must</b> refactor the `CardComponent` and `ListItemComponent`.
-- The `NgFor` directive must be declared and remain inside the `CardComponent`. You might be tempted to move it to the `ParentCardComponent` like `TeacherCardComponent`.
-- `CardComponent` should not contain any `NgIf` or `NgSwitch`.
+- The `@for` must be declared and remain inside the `CardComponent`. You might be tempted to move it to the `ParentCardComponent` like `TeacherCardComponent`.
+- `CardComponent` should not contain any conditions.
 - CSS: try to avoid using `::ng-deep`. Find a better way to handle CSS styling.
 
 ## Bonus Challenges
 
-- Try to work with the new built-in control flow syntax for loops and conditionals (documentation [here](https://angular.dev/guide/templates/control-flow))
 - Use the signal API to manage your components state (documentation [here](https://angular.dev/guide/signals))
 - To reference the template, use a directive instead of magic strings ([What is wrong with magic strings?](https://softwareengineering.stackexchange.com/a/365344))

docs/src/content/docs/fr/challenges/angular/1-projection.md

@@ -37,12 +37,11 @@ Bien que l'application fonctionne, l'expérience développeur est loin d'être o
 ## Contraintes
 
 - Vous <b>devez</b> refactoriser le `CardComponent` et le `ListItemComponent`.
-- La directive `NgFor` doit être déclarée et rester à l'intérieur du `CardComponent`. Vous pourriez être tenté de la déplacer dans le `ParentCardComponent` comme `TeacherCardComponent`.
-- Le composant `CardComponent` ne doit contenir aucun `NgIf` ni `NgSwitch`.
+- La boucle `@for` doit être déclarée et rester à l'intérieur du `CardComponent`. Vous pourriez être tenté de la déplacer dans le `ParentCardComponent` comme `TeacherCardComponent`.
+- Le composant `CardComponent` ne doit contenir aucune condition.
 - CSS: essayez d'éviter d'utiliser `::ng-deep`. Trouvez un meilleur moyen de gérer le style CSS.
 
 ## Challenges Bonus
 
-- Essayez de travailler avec la nouvelle syntaxe de contrôle de flux pour les boucles et les conditions (documentation [ici](https://angular.dev/guide/templates/control-flow))
 - Utilisez l'API des signals pour gérer l'état de vos composants (documentation [ici](https://angular.dev/guide/signals))
 - Pour référencer le template, utilisez une directive au lieu d'une magic string ([Qu'est-ce qui pose problème avec les magic string ?](https://softwareengineering.stackexchange.com/a/365344))