Answer: Challenge-01 (projection, decouple card logic)

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

@@ -1,9 +1,49 @@
-import { ChangeDetectionStrategy, Component } from '@angular/core';
+import {
+  ChangeDetectionStrategy,
+  Component,
+  inject,
+  OnInit,
+} from '@angular/core';
+import { CityStore } from '../../data-access/city.store';
+import {
+  FakeHttpService,
+  randomCity,
+} from '../../data-access/fake-http.service';
+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: `
+    <ng-template #cityTemplate let-item>
+      <app-list-item
+        [name]="item.name"
+        [id]="item.id"
+        (deleteItem)="deleteItem($event)"></app-list-item>
+    </ng-template>
+    <app-card
+      [list]="cities()"
+      [itemTemplate]="cityTemplate"
+      img="assets/img/city.png"
+      customClass="bg-light-purple"
+      (addNewItem)="addItem()"
+      (deleteItem)="deleteItem($event)" />
+  `,
+  imports: [CardComponent, ListItemComponent],
   changeDetection: ChangeDetectionStrategy.OnPush,
 })
-export class CityCardComponent {}
+export class CityCardComponent implements OnInit {
+  private http = inject(FakeHttpService);
+  private store = inject(CityStore);
+  cities = this.store.cities;
+
+  ngOnInit(): void {
+    this.http.fetchCities$.subscribe((s) => this.store.addAll(s));
+  }
+  addItem() {
+    this.store.addOne(randomCity());
+  }
+  deleteItem(id: number) {
+    this.store.deleteOne(id);
+  }
+}

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

@@ -6,35 +6,43 @@ import {
 } 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 { CardComponent } from '../../ui/card/card.component';
 
+import { randStudent } from '../../data-access/fake-http.service';
+import { ListItemComponent } from '../../ui/list-item/list-item.component';
+
 @Component({
   selector: 'app-student-card',
   template: `
+    <ng-template #studentTemplate let-item>
+      <app-list-item
+        [name]="item.firstName"
+        [id]="item.id"
+        (deleteItem)="deleteItem($event)"></app-list-item>
+    </ng-template>
     <app-card
       [list]="students()"
-      [type]="cardType"
-      customClass="bg-light-green" />
+      [itemTemplate]="studentTemplate"
+      img="assets/img/student.webp"
+      customClass="bg-light-green"
+      (addNewItem)="addItem()"
+      (deleteItem)="deleteItem($event)" />
   `,
-  styles: [
-    `
-      ::ng-deep .bg-light-green {
-        background-color: rgba(0, 250, 0, 0.1);
-      }
-    `,
-  ],
-  imports: [CardComponent],
+  imports: [CardComponent, ListItemComponent],
   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));
   }
+  addItem() {
+    this.store.addOne(randStudent());
+  }
+  deleteItem(id: number) {
+    this.store.deleteOne(id);
+  }
 }

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

@@ -1,33 +1,42 @@
 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 { ListItemComponent } from '../../ui/list-item/list-item.component';
 
 @Component({
   selector: 'app-teacher-card',
   template: `
+    <ng-template #teacherTemplate let-item>
+      <app-list-item
+        [name]="item.firstName"
+        [id]="item.id"
+        (deleteItem)="deleteItem($event)"></app-list-item>
+    </ng-template>
     <app-card
       [list]="teachers()"
-      [type]="cardType"
-      customClass="bg-light-red"></app-card>
+      [itemTemplate]="teacherTemplate"
+      img="assets/img/teacher.png"
+      customClass="bg-light-red"
+      (addNewItem)="addItem()"
+      (deleteItem)="deleteItem($event)"></app-card>
   `,
-  styles: [
-    `
-      ::ng-deep .bg-light-red {
-        background-color: rgba(250, 0, 0, 0.1);
-      }
-    `,
-  ],
-  imports: [CardComponent],
+  imports: [CardComponent, ListItemComponent],
 })
 export class TeacherCardComponent implements OnInit {
   private http = inject(FakeHttpService);
   private store = inject(TeacherStore);
-
   teachers = this.store.teachers;
-  cardType = CardType.TEACHER;
 
+  addItem() {
+    this.store.addOne(randTeacher());
+  }
+  deleteItem(id: number) {
+    this.store.deleteOne(id);
+  }
   ngOnInit(): void {
     this.http.fetchTeachers$.subscribe((t) => this.store.addAll(t));
   }

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.component.ts

@@ -1,58 +1,49 @@
-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 { NgOptimizedImage, NgTemplateOutlet } from '@angular/common';
+import { Component, input, output, TemplateRef } from '@angular/core';
+import { City } from '../../model/city.model';
+import { Student } from '../../model/student.model';
+import { Teacher } from '../../model/teacher.model';
 
 @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" />
-      }
+      <img [ngSrc]="img()" 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>
+          <ng-container
+            *ngTemplateOutlet="
+              itemTemplate();
+              context: { $implicit: item }
+            "></ng-container>
         }
       </section>
 
       <button
         class="rounded-sm border border-blue-500 bg-blue-300 p-2"
-        (click)="addNewItem()">
+        (click)="addNewItemClick()">
         Add
       </button>
     </div>
   `,
-  imports: [ListItemComponent, NgOptimizedImage],
+  imports: [NgOptimizedImage, NgTemplateOutlet],
 })
 export class CardComponent {
-  private teacherStore = inject(TeacherStore);
-  private studentStore = inject(StudentStore);
-
-  readonly list = input<any[] | null>(null);
-  readonly type = input.required<CardType>();
+  readonly list = input<Teacher[] | City[] | Student[] | null>(null);
   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());
-    }
+  readonly img = input<string>('');
+  addNewItem = output<void>();
+  deleteItem = output<number>();
+  readonly itemTemplate = input.required<TemplateRef<{
+    $implicit: Teacher | Student | City;
+  }> | null>();
+  addNewItemClick() {
+    this.addNewItem.emit();
+  }
+  deleteItemClick(id: number) {
+    this.deleteItem.emit(id);
   }
 }

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 +18,10 @@ 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>();
-
+  deleteItem = 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.deleteItem.emit(id);
   }
 }

apps/angular/1-projection/src/styles.scss

@@ -1,3 +1,15 @@
 @tailwind base;
 @tailwind components;
 @tailwind utilities;
+
+.bg-light-purple {
+  background-color: rgba(150, 0, 250, 0.1);
+}
+
+.bg-light-green {
+  background-color: rgba(0, 250, 0, 0.1);
+}
+
+.bg-light-red {
+  background-color: rgba(250, 0, 0, 0.1);
+}