Answer:1 Projection

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

@@ -1,9 +1,57 @@
-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 { CardComponent, ItemRefDirective } 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 (addNewItem)="addCity()" [list]="cities()">
+      <img ngSrc="assets/img/city.png" width="200" height="200" />
+      <ng-template itemRef let-item>
+        <app-list-item (onDelete)="deleteCity(item.id)">
+          {{ item.name }}
+        </app-list-item>
+      </ng-template>
+    </app-card>
+  `,
+  styles: [
+    `
+      app-card {
+        background-color: rgba(0, 0, 250, 0.1);
+      }
+    `,
+  ],
+  host: {
+    class: 'flex justify-center p-4',
+  },
+  imports: [
+    CardComponent,
+    ListItemComponent,
+    ItemRefDirective,
+    NgOptimizedImage,
+  ],
   changeDetection: ChangeDetectionStrategy.OnPush,
 })
-export class CityCardComponent {}
+export class CityCardComponent {
+  private http = inject(FakeHttpService);
+  private store = inject(CityStore);
+  cities = this.store.cities;
+
+  ngOnInit(): void {
+    this.http.fetchCities$.subscribe((c) => this.store.addAll(c));
+  }
+
+  deleteCity(id: number) {
+    this.store.deleteOne(id);
+  }
+
+  addCity() {
+    this.store.addOne(randomCity());
+  }
+}

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

@@ -1,40 +1,62 @@
+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 { CardComponent } from '../../ui/card/card.component';
+import { CardComponent, ItemRefDirective } 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" />
+    <app-card (addNewItem)="addStudent()" [list]="students()">
+      <img ngSrc="assets/img/student.webp" width="200" height="200" priority />
+      <ng-template itemRef let-item>
+        <app-list-item (onDelete)="deleteStudent(item.id)">
+          {{ item.firstName }}
+        </app-list-item>
+      </ng-template>
+    </app-card>
   `,
   styles: [
     `
-      ::ng-deep .bg-light-green {
+      app-card {
         background-color: rgba(0, 250, 0, 0.1);
       }
     `,
   ],
-  imports: [CardComponent],
+  host: {
+    class: 'flex justify-center p-4',
+  },
+  imports: [
+    CardComponent,
+    ListItemComponent,
+    ItemRefDirective,
+    NgOptimizedImage,
+  ],
   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));
   }
+
+  deleteStudent(id: number) {
+    this.store.deleteOne(id);
+  }
+
+  addStudent() {
+    this.store.addOne(randStudent());
+  }
 }

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

@@ -1,34 +1,55 @@
+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 { CardComponent } from '../../ui/card/card.component';
+import { CardComponent, ItemRefDirective } 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>
+    <app-card (addNewItem)="addTeacher()" [list]="teachers()">
+      <img ngSrc="assets/img/teacher.png" width="200" height="200" priority />
+      <ng-template itemRef let-item>
+        <app-list-item (onDelete)="deleteTeacher(item.id)">
+          {{ item.firstName }}
+        </app-list-item>
+      </ng-template>
+    </app-card>
   `,
   styles: [
     `
-      ::ng-deep .bg-light-red {
+      app-card {
         background-color: rgba(250, 0, 0, 0.1);
       }
     `,
   ],
-  imports: [CardComponent],
+  host: {
+    class: 'flex justify-center p-4',
+  },
+  imports: [
+    CardComponent,
+    ListItemComponent,
+    NgOptimizedImage,
+    ItemRefDirective,
+  ],
 })
 export class TeacherCardComponent implements OnInit {
   private http = inject(FakeHttpService);
   private store = inject(TeacherStore);
 
   teachers = this.store.teachers;
-  cardType = CardType.TEACHER;
 
   ngOnInit(): void {
     this.http.fetchTeachers$.subscribe((t) => this.store.addAll(t));
   }
+  addTeacher() {
+    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[]>([]);
+  cities = signal<City[]>([]);
 
   addAll(cities: City[]) {
     this.cities.set(cities);

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

@@ -1,58 +1,48 @@
-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,
+  Directive,
+  input,
+  output,
+  TemplateRef,
+} from '@angular/core';
+
+@Directive({
+  selector: '[itemRef]',
+  standalone: true,
+})
+export class ItemRefDirective {}
 
 @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" />
+    <ng-content select="img"></ng-content>
+    <section>
+      @for (item of list(); track item.id) {
+        <ng-template
+          [ngTemplateOutlet]="itemRef"
+          [ngTemplateOutletContext]="{ $implicit: item }"></ng-template>
       }
-      @if (type() === CardType.STUDENT) {
-        <img ngSrc="assets/img/student.webp" width="200" height="200" />
-      }
-
-      <section>
-        @for (item of list(); track item) {
-          <app-list-item
-            [name]="item.firstName"
-            [id]="item.id"
-            [type]="type()"></app-list-item>
-        }
-      </section>
-
-      <button
-        class="rounded-sm border border-blue-500 bg-blue-300 p-2"
-        (click)="addNewItem()">
-        Add
-      </button>
-    </div>
+    </section>
+    <button
+      class="rounded-sm border border-blue-500 bg-blue-300 p-2"
+      (click)="addNewItem.emit()">
+      Add
+    </button>
   `,
-  imports: [ListItemComponent, NgOptimizedImage],
+  host: {
+    class: 'flex w-fit flex-col gap-3 rounded-md border-2 border-black p-4',
+  },
+  imports: [NgTemplateOutlet],
 })
 export class CardComponent {
-  private teacherStore = inject(TeacherStore);
-  private studentStore = inject(StudentStore);
-
+  addNewItem = output<void>();
   readonly list = input<any[] | null>(null);
-  readonly type = input.required<CardType>();
-  readonly customClass = input('');
-
-  CardType = CardType;
 
-  addNewItem() {
-    const type = this.type();
-    if (type === CardType.TEACHER) {
-      this.teacherStore.addOne(randTeacher());
-    } else if (type === CardType.STUDENT) {
-      this.studentStore.addOne(randStudent());
-    }
-  }
+  // [For My Ref] we can leverage on ng-content and template to reduce duplication and better code managment with reusability without changing much
+  // Using ContentChild to get the template reference from projected content read as TemplateRef without it doesnt give TemplateRef
+  @ContentChild(ItemRefDirective, { read: TemplateRef }) itemRef!: TemplateRef<{
+    $implicit: any;
+  }>;
 }

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

@@ -1,39 +1,18 @@
-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';
+import { ChangeDetectionStrategy, Component, output } from '@angular/core';
 
 @Component({
   selector: 'app-list-item',
   template: `
-    <div class="border-grey-300 flex justify-between border px-2 py-1">
-      {{ name() }}
-      <button (click)="delete(id())">
-        <img class="h-5" src="assets/svg/trash.svg" />
-      </button>
-    </div>
+    <ng-content></ng-content>
+    <button (click)="onDelete.emit()">
+      <img class="h-5" src="assets/svg/trash.svg" />
+    </button>
   `,
+  host: {
+    class: 'border-grey-300 flex justify-between border px-2 py-1',
+  },
   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>();
-
-  delete(id: number) {
-    const type = this.type();
-    if (type === CardType.TEACHER) {
-      this.teacherStore.deleteOne(id);
-    } else if (type === CardType.STUDENT) {
-      this.studentStore.deleteOne(id);
-    }
-  }
+  onDelete = output<void>();
 }