Answer:1 content projection solution

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

@@ -1,9 +1,51 @@
-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 { CardType } from '../../model/card.model';
+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()"
+      [itemTemplate]="itemTemplate"
+      (onAddNewItem)="addNewCity()">
+      <img ngSrc="assets/img/city.png" width="200" height="200" />
+    </app-card>
+
+    <ng-template #itemTemplate let-item>
+      <app-list-item
+        [name]="item.name"
+        [id]="item.id"
+        [type]="cardType"
+        (onDeleteItem)="deleteCity($event)"></app-list-item>
+    </ng-template>
+  `,
+  imports: [CardComponent, NgOptimizedImage, ListItemComponent],
   changeDetection: ChangeDetectionStrategy.OnPush,
 })
-export class CityCardComponent {}
+export class CityCardComponent {
+  private http = inject(FakeHttpService);
+  private store = inject(CityStore);
+
+  cities = this.store.cities;
+  cardType = CardType.CITY;
+
+  ngOnInit(): void {
+    this.http.fetchCities$.subscribe((c) => this.store.addAll(c));
+  }
+
+  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

@@ -1,31 +1,49 @@
+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 { Store } from '../../data-access/store';
 import { StudentStore } from '../../data-access/student.store';
 import { CardType } from '../../model/card.model';
 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" />
+      class="bg-light-green"
+      [itemTemplate]="itemTemplate"
+      (onAddNewItem)="addNewItem()">
+      <img ngSrc="assets/img/student.webp" width="200" height="200" />
+    </app-card>
+
+    <ng-template #itemTemplate let-item>
+      <app-list-item
+        [name]="item.firstName"
+        [id]="item.id"
+        [type]="cardType"
+        (onDeleteItem)="deleteStudent($event)"></app-list-item>
+    </ng-template>
   `,
   styles: [
     `
-      ::ng-deep .bg-light-green {
+      .bg-light-green {
         background-color: rgba(0, 250, 0, 0.1);
       }
     `,
   ],
-  imports: [CardComponent],
+  imports: [CardComponent, NgOptimizedImage, ListItemComponent],
   changeDetection: ChangeDetectionStrategy.OnPush,
+  providers: [{ provide: Store, useExisting: StudentStore }],
 })
 export class StudentCardComponent implements OnInit {
   private http = inject(FakeHttpService);
@@ -37,4 +55,12 @@ export class StudentCardComponent implements OnInit {
   ngOnInit(): void {
     this.http.fetchStudents$.subscribe((s) => this.store.addAll(s));
   }
+
+  addNewItem() {
+    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 +1,47 @@
-import { Component, inject, OnInit } from '@angular/core';
-import { FakeHttpService } from '../../data-access/fake-http.service';
+import { NgOptimizedImage } from '@angular/common';
+import {
+  ChangeDetectionStrategy,
+  Component,
+  inject,
+  OnInit,
+} 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 { 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>
+      [itemTemplate]="itemTemplate"
+      class="bg-light-red"
+      (onAddNewItem)="addNewTeacher()">
+      <img priority ngSrc="assets/img/teacher.png" width="200" height="200" />
+    </app-card>
+
+    <ng-template #itemTemplate let-item>
+      <app-list-item
+        [name]="item.firstName"
+        [id]="item.id"
+        [type]="cardType"
+        (onDeleteItem)="deleteTeacher($event)"></app-list-item>
+    </ng-template>
   `,
   styles: [
     `
-      ::ng-deep .bg-light-red {
+      .bg-light-red {
         background-color: rgba(250, 0, 0, 0.1);
       }
     `,
   ],
-  imports: [CardComponent],
+  imports: [CardComponent, NgOptimizedImage, ListItemComponent],
+  changeDetection: ChangeDetectionStrategy.OnPush,
 })
 export class TeacherCardComponent implements OnInit {
   private http = inject(FakeHttpService);
@@ -31,4 +53,12 @@ export class TeacherCardComponent implements OnInit {
   ngOnInit(): void {
     this.http.fetchTeachers$.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/data-access/store.ts

@@ -0,0 +1,9 @@
+import { signal } from '@angular/core';
+
+export abstract class Store<T> {
+  protected readonly items = signal<T[]>([]);
+
+  abstract addAll(items: T[]): void;
+  abstract addOne(item: T): void;
+  abstract deleteOne(id: number): void;
+}

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

@@ -1,58 +1,36 @@
-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, input, output, TemplateRef } from '@angular/core';
 
 @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 select="img"></ng-content>
 
-      <section>
-        @for (item of list(); track item) {
-          <app-list-item
-            [name]="item.firstName"
-            [id]="item.id"
-            [type]="type()"></app-list-item>
-        }
-      </section>
+    <section>
+      @for (item of list(); track item) {
+        <ng-container
+          [ngTemplateOutlet]="itemTemplate()"
+          [ngTemplateOutletContext]="{ $implicit: item }"></ng-container>
+      }
+    </section>
 
-      <button
-        class="rounded-sm border border-blue-500 bg-blue-300 p-2"
-        (click)="addNewItem()">
-        Add
-      </button>
-    </div>
+    <button
+      class="rounded-sm border border-blue-500 bg-blue-300 p-2"
+      (click)="addNewItem()">
+      Add
+    </button>
   `,
-  imports: [ListItemComponent, NgOptimizedImage],
+  host: {
+    class: 'border-2 border-black rounded-md p-4 w-fit flex flex-col gap-3',
+  },
+  imports: [NgTemplateOutlet],
 })
-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('');
-
-  CardType = CardType;
+export class CardComponent<T> {
+  readonly list = input<T[] | null>(null);
+  readonly itemTemplate = input<TemplateRef<any> | null>(null);
+  onAddNewItem = output();
 
   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

@@ -1,11 +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({
@@ -21,19 +19,13 @@ 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>();
 
+  readonly onDeleteItem = 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.onDeleteItem.emit(id);
   }
 }