Answer:1 - Resolve projection challenge

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

@@ -1,13 +1,62 @@
-import { Component, OnInit } from '@angular/core';
+import {
+  Component,
+  OnInit,
+  signal,
+  ViewEncapsulation,
+  WritableSignal,
+} from '@angular/core';
+import { CityStore } from '../../data-access/city.store';
+import {
+  FakeHttpService,
+  randomCity,
+} from '../../data-access/fake-http.service';
+import { CardType } from '../../model/card.model';
+import { City } from '../../model/city.model';
+import { CardComponent } from '../../ui/card/card.component';
 
 @Component({
   selector: 'app-city-card',
-  template: 'TODO City',
+  template: `
+    <app-card
+      [list]="cities()"
+      [type]="cardType"
+      customClass="bg-light-blue"
+      (addItem)="addCity()"
+      (delete)="deleteItem($event)">
+      <img src="assets/img/city.png" width="200px" />
+    </app-card>
+  `,
   standalone: true,
-  imports: [],
+  styles: [
+    `
+      .bg-light-blue {
+        background-color: rgba(0, 0, 250, 0.1);
+      }
+    `,
+  ],
+  encapsulation: ViewEncapsulation.None,
+  imports: [CardComponent],
 })
 export class CityCardComponent implements OnInit {
-  constructor() {}
+  cities: WritableSignal<City[]> = signal([]);
+  cardType = CardType.CITY;
 
-  ngOnInit(): void {}
+  constructor(
+    private http: FakeHttpService,
+    private store: CityStore,
+  ) {}
+
+  ngOnInit(): void {
+    this.http.fetchCities$.subscribe((c) => this.store.addAll(c));
+
+    this.store.cities$.subscribe((c) => this.cities.set(c));
+  }
+
+  addCity() {
+    this.store.addOne(randomCity());
+  }
+
+  deleteItem(id: number) {
+    this.store.deleteOne(id);
+  }
 }

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

@@ -1,5 +1,14 @@
-import { Component, OnInit } from '@angular/core';
-import { FakeHttpService } from '../../data-access/fake-http.service';
+import {
+  Component,
+  OnInit,
+  signal,
+  ViewEncapsulation,
+  WritableSignal,
+} from '@angular/core';
+import {
+  FakeHttpService,
+  randStudent,
+} 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';
@@ -9,22 +18,27 @@ import { CardComponent } from '../../ui/card/card.component';
   selector: 'app-student-card',
   template: `
     <app-card
-      [list]="students"
+      [list]="students()"
       [type]="cardType"
-      customClass="bg-light-green"></app-card>
+      customClass="bg-light-green"
+      (addItem)="addStudent()"
+      (delete)="deleteItem($event)">
+      <img src="assets/img/student.webp" width="200px" />
+    </app-card>
   `,
   standalone: true,
   styles: [
     `
-      ::ng-deep .bg-light-green {
+      .bg-light-green {
         background-color: rgba(0, 250, 0, 0.1);
       }
     `,
   ],
+  encapsulation: ViewEncapsulation.None,
   imports: [CardComponent],
 })
 export class StudentCardComponent implements OnInit {
-  students: Student[] = [];
+  students: WritableSignal<Student[]> = signal([]);
   cardType = CardType.STUDENT;
 
   constructor(
@@ -35,6 +49,14 @@ export class StudentCardComponent implements OnInit {
   ngOnInit(): void {
     this.http.fetchStudents$.subscribe((s) => this.store.addAll(s));
 
-    this.store.students$.subscribe((s) => (this.students = s));
+    this.store.students$.subscribe((s) => this.students.set(s));
+  }
+
+  addStudent() {
+    this.store.addOne(randStudent());
+  }
+
+  deleteItem(id: number) {
+    this.store.deleteOne(id);
   }
 }

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

@@ -1,5 +1,14 @@
-import { Component, OnInit } from '@angular/core';
-import { FakeHttpService } from '../../data-access/fake-http.service';
+import {
+  Component,
+  OnInit,
+  signal,
+  ViewEncapsulation,
+  WritableSignal,
+} from '@angular/core';
+import {
+  FakeHttpService,
+  randTeacher,
+} 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';
@@ -9,22 +18,27 @@ import { CardComponent } from '../../ui/card/card.component';
   selector: 'app-teacher-card',
   template: `
     <app-card
-      [list]="teachers"
+      [list]="teachers()"
       [type]="cardType"
-      customClass="bg-light-red"></app-card>
+      customClass="bg-light-red"
+      (addItem)="addTeacher()"
+      (delete)="deleteItem($event)">
+      <img src="assets/img/teacher.png" width="200px" />
+    </app-card>
   `,
   styles: [
     `
-      ::ng-deep .bg-light-red {
+      .bg-light-red {
         background-color: rgba(250, 0, 0, 0.1);
       }
     `,
   ],
+  encapsulation: ViewEncapsulation.None,
   standalone: true,
   imports: [CardComponent],
 })
 export class TeacherCardComponent implements OnInit {
-  teachers: Teacher[] = [];
+  teachers: WritableSignal<Teacher[]> = signal([]);
   cardType = CardType.TEACHER;
 
   constructor(
@@ -35,6 +49,14 @@ export class TeacherCardComponent implements OnInit {
   ngOnInit(): void {
     this.http.fetchTeachers$.subscribe((t) => this.store.addAll(t));
 
-    this.store.teachers$.subscribe((t) => (this.teachers = t));
+    this.store.teachers$.subscribe((t) => this.teachers.set(t));
+  }
+
+  addTeacher() {
+    this.store.addOne(randTeacher());
+  }
+
+  deleteItem(id: number) {
+    this.store.deleteOne(id);
   }
 }

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

@@ -13,8 +13,8 @@ export class CityStore {
     this.cities.next(cities);
   }
 
-  addOne(student: City) {
-    this.cities.next([...this.cities.value, student]);
+  addOne(city: City) {
+    this.cities.next([...this.cities.value, city]);
   }
 
   deleteOne(id: number) {

apps/angular/1-projection/src/app/data-access/fake-http.service.ts

@@ -45,7 +45,6 @@ const students: Student[] = [
   randStudent(),
   randStudent(),
   randStudent(),
-  randStudent(),
 ];
 
 const factoryCity = incrementalNumber();
@@ -56,7 +55,7 @@ export const randomCity = (): City => ({
   country: randCountry(),
 });
 
-const cities = [randomCity(), randomCity(), randomCity()];
+const cities = [randomCity(), randomCity(), randomCity(), randomCity()];
 
 @Injectable({
   providedIn: 'root',

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

@@ -1,8 +1,5 @@
-import { NgFor, NgIf } from '@angular/common';
-import { Component, 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';
+import { NgFor } from '@angular/common';
+import { Component, EventEmitter, Input, Output } from '@angular/core';
 import { CardType } from '../../model/card.model';
 import { ListItemComponent } from '../list-item/list-item.component';
 
@@ -12,50 +9,36 @@ import { ListItemComponent } from '../list-item/list-item.component';
     <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" />
+      <ng-content></ng-content>
 
       <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.id) {
+          <app-list-item
+            [name]="item.firstName || item.name"
+            [id]="item.id"
+            [type]="type"
+            (deleteItem)="delete.emit($event)"></app-list-item>
+        }
       </section>
 
       <button
         class="rounded-sm border border-blue-500 bg-blue-300 p-2"
-        (click)="addNewItem()">
+        (click)="addItem.emit()">
         Add
       </button>
     </div>
   `,
   standalone: true,
-  imports: [NgIf, NgFor, ListItemComponent],
+  imports: [NgFor, ListItemComponent],
 })
 export class CardComponent {
   @Input() list: any[] | null = null;
   @Input() type!: CardType;
   @Input() customClass = '';
+  @Output() addItem = new EventEmitter<void>();
+  @Output() delete = new EventEmitter<number>();
 
   CardType = CardType;
 
-  constructor(
-    private teacherStore: TeacherStore,
-    private studentStore: StudentStore,
-  ) {}
-
-  addNewItem() {
-    if (this.type === CardType.TEACHER) {
-      this.teacherStore.addOne(randTeacher());
-    } else if (this.type === CardType.STUDENT) {
-      this.studentStore.addOne(randStudent());
-    }
-  }
+  constructor() {}
 }

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

@@ -1,14 +1,12 @@
-import { Component, Input } from '@angular/core';
-import { StudentStore } from '../../data-access/student.store';
-import { TeacherStore } from '../../data-access/teacher.store';
+import { Component, EventEmitter, Input, Output } from '@angular/core';
 import { CardType } from '../../model/card.model';
 
 @Component({
   selector: 'app-list-item',
   template: `
     <div class="border-grey-300 flex justify-between border px-2 py-1">
       {{ name }}
-      <button (click)="delete(id)">
+      <button (click)="deleteItem.emit(id)">
         <img class="h-5" src="assets/svg/trash.svg" />
       </button>
     </div>
@@ -19,17 +17,7 @@ export class ListItemComponent {
   @Input() id!: number;
   @Input() name!: string;
   @Input() type!: CardType;
+  @Output() deleteItem = new EventEmitter<number>();
 
-  constructor(
-    private teacherStore: TeacherStore,
-    private studentStore: StudentStore,
-  ) {}
-
-  delete(id: number) {
-    if (this.type === CardType.TEACHER) {
-      this.teacherStore.deleteOne(id);
-    } else if (this.type === CardType.STUDENT) {
-      this.studentStore.deleteOne(id);
-    }
-  }
+  constructor() {}
 }