Answer: 1 Angular Projection

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

@@ -1,9 +1,53 @@
-import { ChangeDetectionStrategy, Component } from '@angular/core';
+import { NgOptimizedImage } from '@angular/common';
+import { ChangeDetectionStrategy, Component, inject } from '@angular/core';
+import { CityStore } from '../../data-access/city.store';
+import {
+  FakeHttpService,
+  randomCity,
+} from '../../data-access/fake-http.service';
+import { CardListItemTemplateDirective } from '../../ui/card/card-list-item-template.directive';
+import { CardComponent } from '../../ui/card/card.component';
+import { ListItemComponent } from '../../ui/list-item/list-item.component';
 
 @Component({
   selector: 'app-city-card',
-  template: 'TODO City',
-  imports: [],
+  template: `
+    <app-card
+      [list]="cities()"
+      customClass="bg-light-blue"
+      (onAddNewItem)="addNewCity()">
+      <img ngSrc="assets/img/city.png" width="200" height="200" />
+
+      <ng-template appCardListItem let-item="item">
+        <app-list-item
+          [name]="item.name"
+          [id]="item.id"
+          (onDelete)="deleteCity(item.id)"></app-list-item>
+      </ng-template>
+    </app-card>
+  `,
+  imports: [
+    CardComponent,
+    CardListItemTemplateDirective,
+    ListItemComponent,
+    NgOptimizedImage,
+  ],
   changeDetection: ChangeDetectionStrategy.OnPush,
 })
-export class CityCardComponent {}
+export class CityCardComponent {
+  private http = inject(FakeHttpService);
+  store = inject(CityStore);
+  cities = this.store.cities;
+
+  ngOnInit(): void {
+    this.http.fetchCities$.subscribe((s) => this.store.addAll(s));
+  }
+
+  addNewCity() {
+    this.store.addOne(randomCity());
+  }
+
+  deleteCity(id: number) {
+    this.store.deleteOne(id);
+  }
+}

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

@@ -1,40 +1,59 @@
+import { NgOptimizedImage } from '@angular/common';
 import {
   ChangeDetectionStrategy,
   Component,
   inject,
   OnInit,
 } from '@angular/core';
-import { FakeHttpService } from '../../data-access/fake-http.service';
+import {
+  FakeHttpService,
+  randStudent,
+} from '../../data-access/fake-http.service';
 import { StudentStore } from '../../data-access/student.store';
-import { CardType } from '../../model/card.model';
+import { CardListItemTemplateDirective } from '../../ui/card/card-list-item-template.directive';
 import { CardComponent } from '../../ui/card/card.component';
+import { ListItemComponent } from '../../ui/list-item/list-item.component';
 
 @Component({
   selector: 'app-student-card',
   template: `
     <app-card
       [list]="students()"
-      [type]="cardType"
-      customClass="bg-light-green" />
+      customClass="bg-light-green"
+      (onAddNewItem)="addNewStudent()">
+      <img ngSrc="assets/img/student.webp" width="200" height="200" />
+
+      <ng-template appCardListItem let-item="item">
+        <app-list-item
+          [name]="item.firstName"
+          [id]="item.id"
+          (onDelete)="deleteStudent(item.id)"></app-list-item>
+      </ng-template>
+    </app-card>
   `,
-  styles: [
-    `
-      ::ng-deep .bg-light-green {
-        background-color: rgba(0, 250, 0, 0.1);
-      }
-    `,
+  imports: [
+    CardComponent,
+    CardListItemTemplateDirective,
+    NgOptimizedImage,
+    ListItemComponent,
   ],
-  imports: [CardComponent],
   changeDetection: ChangeDetectionStrategy.OnPush,
 })
 export class StudentCardComponent implements OnInit {
   private http = inject(FakeHttpService);
   private store = inject(StudentStore);
 
   students = this.store.students;
-  cardType = CardType.STUDENT;
 
   ngOnInit(): void {
     this.http.fetchStudents$.subscribe((s) => this.store.addAll(s));
   }
+
+  addNewStudent() {
+    this.store.addOne(randStudent());
+  }
+
+  deleteStudent(id: number) {
+    this.store.deleteOne(id);
+  }
 }

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

@@ -1,25 +1,38 @@
+import { NgOptimizedImage } from '@angular/common';
 import { Component, inject, OnInit } from '@angular/core';
-import { FakeHttpService } from '../../data-access/fake-http.service';
+import {
+  FakeHttpService,
+  randTeacher,
+} from '../../data-access/fake-http.service';
 import { TeacherStore } from '../../data-access/teacher.store';
 import { CardType } from '../../model/card.model';
+import { CardListItemTemplateDirective } from '../../ui/card/card-list-item-template.directive';
 import { CardComponent } from '../../ui/card/card.component';
+import { ListItemComponent } from '../../ui/list-item/list-item.component';
 
 @Component({
   selector: 'app-teacher-card',
   template: `
     <app-card
       [list]="teachers()"
-      [type]="cardType"
-      customClass="bg-light-red"></app-card>
+      customClass="bg-light-red"
+      (onAddNewItem)="addNewTeacher()">
+      <img ngSrc="assets/img/teacher.png" width="200" height="200" />
+
+      <ng-template appCardListItem let-item="item">
+        <app-list-item
+          [name]="item.firstName"
+          [id]="item.id"
+          (onDelete)="deleteTeacher(item.id)"></app-list-item>
+      </ng-template>
+    </app-card>
   `,
-  styles: [
-    `
-      ::ng-deep .bg-light-red {
-        background-color: rgba(250, 0, 0, 0.1);
-      }
-    `,
+  imports: [
+    CardComponent,
+    CardListItemTemplateDirective,
+    NgOptimizedImage,
+    ListItemComponent,
   ],
-  imports: [CardComponent],
 })
 export class TeacherCardComponent implements OnInit {
   private http = inject(FakeHttpService);
@@ -31,4 +44,12 @@ export class TeacherCardComponent implements OnInit {
   ngOnInit(): void {
     this.http.fetchTeachers$.subscribe((t) => this.store.addAll(t));
   }
+
+  addNewTeacher() {
+    this.store.addOne(randTeacher());
+  }
+
+  deleteTeacher(id: number) {
+    this.store.deleteOne(id);
+  }
 }

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

@@ -5,7 +5,7 @@ import { City } from '../model/city.model';
   providedIn: 'root',
 })
 export class CityStore {
-  private cities = signal<City[]>([]);
+  public cities = signal<City[]>([]);
 
   addAll(cities: City[]) {
     this.cities.set(cities);

apps/angular/1-projection/src/app/ui/card/card-list-item-template.directive.ts

@@ -0,0 +1,15 @@
+import { Directive, TemplateRef, inject } from '@angular/core';
+import { City } from '../../model/city.model';
+import { Student } from '../../model/student.model';
+import { Teacher } from '../../model/teacher.model';
+
+type CardItem = Student | City | Teacher;
+
+@Directive({
+  selector: 'ng-template[appCardListItem]',
+  exportAs: 'appCardListItem',
+})
+export class CardListItemTemplateDirective {
+  template: TemplateRef<{ $implicit: CardItem; item: CardItem }> =
+    inject(TemplateRef);
+}

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

@@ -1,30 +1,21 @@
-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';
-import { CardType } from '../../model/card.model';
-import { ListItemComponent } from '../list-item/list-item.component';
+import { NgTemplateOutlet } from '@angular/common';
+import { Component, contentChild, input, output } from '@angular/core';
+import { CardListItemTemplateDirective } from './card-list-item-template.directive';
 
 @Component({
   selector: 'app-card',
   template: `
     <div
       class="flex w-fit flex-col gap-3 rounded-md border-2 border-black p-4"
       [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" />
-      }
-
+      <ng-content />
       <section>
         @for (item of list(); track item) {
-          <app-list-item
-            [name]="item.firstName"
-            [id]="item.id"
-            [type]="type()"></app-list-item>
+          <ng-container
+            *ngTemplateOutlet="
+              listItemTemplate()?.template ?? null;
+              context: { $implicit: item, item: item }
+            "></ng-container>
         }
       </section>
 
@@ -35,24 +26,32 @@ import { ListItemComponent } from '../list-item/list-item.component';
       </button>
     </div>
   `,
-  imports: [ListItemComponent, NgOptimizedImage],
+  styles: [
+    `
+      .bg-light-red {
+        background-color: rgba(250, 0, 0, 0.1);
+      }
+
+      .bg-light-green {
+        background-color: rgba(0, 250, 0, 0.1);
+      }
+
+      .bg-light-blue {
+        background-color: rgba(0, 0, 250, 0.1);
+      }
+    `,
+  ],
+  imports: [NgTemplateOutlet, CardListItemTemplateDirective],
 })
 export class CardComponent {
-  private teacherStore = inject(TeacherStore);
-  private studentStore = inject(StudentStore);
-
   readonly list = input<any[] | null>(null);
-  readonly type = input.required<CardType>();
   readonly customClass = input('');
+  onAddNewItem = output<void>();
 
-  CardType = CardType;
+  // Use contentChild to query for the directive
+  listItemTemplate = contentChild(CardListItemTemplateDirective);
 
   addNewItem() {
-    const type = this.type();
-    if (type === CardType.TEACHER) {
-      this.teacherStore.addOne(randTeacher());
-    } else if (type === CardType.STUDENT) {
-      this.studentStore.addOne(randStudent());
-    }
+    this.onAddNewItem.emit();
   }
 }

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

@@ -1,12 +1,9 @@
 import {
   ChangeDetectionStrategy,
   Component,
-  inject,
   input,
+  output,
 } from '@angular/core';
-import { StudentStore } from '../../data-access/student.store';
-import { TeacherStore } from '../../data-access/teacher.store';
-import { CardType } from '../../model/card.model';
 
 @Component({
   selector: 'app-list-item',
@@ -21,19 +18,11 @@ import { CardType } from '../../model/card.model';
   changeDetection: ChangeDetectionStrategy.OnPush,
 })
 export class ListItemComponent {
-  private teacherStore = inject(TeacherStore);
-  private studentStore = inject(StudentStore);
-
   readonly id = input.required<number>();
   readonly name = input.required<string>();
-  readonly type = input.required<CardType>();
+  onDelete = output<number>();
 
   delete(id: number) {
-    const type = this.type();
-    if (type === CardType.TEACHER) {
-      this.teacherStore.deleteOne(id);
-    } else if (type === CardType.STUDENT) {
-      this.studentStore.deleteOne(id);
-    }
+    this.onDelete.emit(id);
   }
 }