From 12dd8adb4dd7b32f46e7f9a932f92a857052a5bf Mon Sep 17 00:00:00 2001
From: Assaf <1214assaf@gmail.com>
Date: Fri, 8 May 2026 12:32:13 +0300
Subject: [PATCH] feat(projection): solve challenge 1 using ng-content and
 ngTemplateOutlet

---
 .../city-card/city-card.component.ts          | 42 ++++++++++++--
 .../student-card/student-card.component.ts    | 45 ++++++++++-----
 .../teacher-card/teacher-card.component.ts    | 45 ++++++++++-----
 .../src/app/data-access/city.store.ts         |  2 +-
 .../src/app/ui/card/card-item.directive.ts    | 19 +++++++
 .../src/app/ui/card/card.component.ts         | 56 +++++++------------
 .../app/ui/list-item/list-item.component.ts   | 20 +------
 7 files changed, 142 insertions(+), 87 deletions(-)
 create mode 100644 apps/angular/1-projection/src/app/ui/card/card-item.directive.ts

diff --git a/apps/angular/1-projection/src/app/component/city-card/city-card.component.ts b/apps/angular/1-projection/src/app/component/city-card/city-card.component.ts
index 8895c8c84..64d20c5de 100644
--- a/apps/angular/1-projection/src/app/component/city-card/city-card.component.ts
+++ b/apps/angular/1-projection/src/app/component/city-card/city-card.component.ts
@@ -1,9 +1,43 @@
-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 { CardItemDirective } from '../../ui/card/card-item.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]="store.cities()"
+      customClass="bg-blue-100"
+      (add)="store.addOne(randomCity())">
+      <ng-template appCardItem let-city>
+        <app-list-item
+          [id]="$any(city).id"
+          [name]="$any(city).name"
+          (delete)="store.deleteOne($event)" />
+      </ng-template>
+    </app-card>
+  `,
+  imports: [CardComponent, CardItemDirective, ListItemComponent],
   changeDetection: ChangeDetectionStrategy.OnPush,
 })
-export class CityCardComponent {}
+export class CityCardComponent implements OnInit {
+  private http = inject(FakeHttpService);
+  protected store = inject(CityStore);
+
+  randomCity = randomCity;
+
+  ngOnInit(): void {
+    this.http.fetchCities$.subscribe((c) => this.store.addAll(c));
+  }
+}
diff --git a/apps/angular/1-projection/src/app/component/student-card/student-card.component.ts b/apps/angular/1-projection/src/app/component/student-card/student-card.component.ts
index bdfa4abd4..c8401976e 100644
--- a/apps/angular/1-projection/src/app/component/student-card/student-card.component.ts
+++ b/apps/angular/1-projection/src/app/component/student-card/student-card.component.ts
@@ -1,38 +1,53 @@
+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 { CardItemDirective } from '../../ui/card/card-item.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" />
+      [list]="store.students()"
+      customClass="bg-green-100"
+      (add)="store.addOne(randStudent())">
+      <img
+        card-image
+        ngSrc="assets/img/student.webp"
+        width="200"
+        height="200"
+        alt="" />
+      <ng-template appCardItem let-student>
+        <app-list-item
+          [id]="$any(student).id"
+          [name]="$any(student).firstName"
+          (delete)="store.deleteOne($event)" />
+      </ng-template>
+    </app-card>
   `,
-  styles: [
-    `
-      ::ng-deep .bg-light-green {
-        background-color: rgba(0, 250, 0, 0.1);
-      }
-    `,
+  imports: [
+    CardComponent,
+    CardItemDirective,
+    ListItemComponent,
+    NgOptimizedImage,
   ],
-  imports: [CardComponent],
   changeDetection: ChangeDetectionStrategy.OnPush,
 })
 export class StudentCardComponent implements OnInit {
   private http = inject(FakeHttpService);
-  private store = inject(StudentStore);
+  protected store = inject(StudentStore);
 
-  students = this.store.students;
-  cardType = CardType.STUDENT;
+  randStudent = randStudent;
 
   ngOnInit(): void {
     this.http.fetchStudents$.subscribe((s) => this.store.addAll(s));
diff --git a/apps/angular/1-projection/src/app/component/teacher-card/teacher-card.component.ts b/apps/angular/1-projection/src/app/component/teacher-card/teacher-card.component.ts
index adf0ad3c1..ab54013d4 100644
--- a/apps/angular/1-projection/src/app/component/teacher-card/teacher-card.component.ts
+++ b/apps/angular/1-projection/src/app/component/teacher-card/teacher-card.component.ts
@@ -1,32 +1,47 @@
+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 { CardItemDirective } from '../../ui/card/card-item.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>
+      [list]="store.teachers()"
+      customClass="bg-red-100"
+      (add)="store.addOne(randTeacher())">
+      <img
+        card-image
+        ngSrc="assets/img/teacher.png"
+        width="200"
+        height="200"
+        alt="" />
+      <ng-template appCardItem let-teacher>
+        <app-list-item
+          [id]="$any(teacher).id"
+          [name]="$any(teacher).firstName"
+          (delete)="store.deleteOne($event)" />
+      </ng-template>
+    </app-card>
   `,
-  styles: [
-    `
-      ::ng-deep .bg-light-red {
-        background-color: rgba(250, 0, 0, 0.1);
-      }
-    `,
+  imports: [
+    CardComponent,
+    CardItemDirective,
+    ListItemComponent,
+    NgOptimizedImage,
   ],
-  imports: [CardComponent],
 })
 export class TeacherCardComponent implements OnInit {
   private http = inject(FakeHttpService);
-  private store = inject(TeacherStore);
+  protected store = inject(TeacherStore);
 
-  teachers = this.store.teachers;
-  cardType = CardType.TEACHER;
+  randTeacher = randTeacher;
 
   ngOnInit(): void {
     this.http.fetchTeachers$.subscribe((t) => this.store.addAll(t));
diff --git a/apps/angular/1-projection/src/app/data-access/city.store.ts b/apps/angular/1-projection/src/app/data-access/city.store.ts
index a8b523569..9fbcb346b 100644
--- a/apps/angular/1-projection/src/app/data-access/city.store.ts
+++ b/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);
diff --git a/apps/angular/1-projection/src/app/ui/card/card-item.directive.ts b/apps/angular/1-projection/src/app/ui/card/card-item.directive.ts
new file mode 100644
index 000000000..940b9104e
--- /dev/null
+++ b/apps/angular/1-projection/src/app/ui/card/card-item.directive.ts
@@ -0,0 +1,19 @@
+import { Directive, inject, TemplateRef } from '@angular/core';
+
+export interface CardItemContext<T> {
+  $implicit: T;
+}
+
+@Directive({
+  selector: '[appCardItem]',
+})
+export class CardItemDirective<T> {
+  templateRef = inject<TemplateRef<CardItemContext<T>>>(TemplateRef);
+
+  static ngTemplateContextGuard<T>(
+    _dir: CardItemDirective<T>,
+    ctx: unknown,
+  ): ctx is CardItemContext<T> {
+    return true;
+  }
+}
diff --git a/apps/angular/1-projection/src/app/ui/card/card.component.ts b/apps/angular/1-projection/src/app/ui/card/card.component.ts
index 166d9c49a..59ab5d0c3 100644
--- a/apps/angular/1-projection/src/app/ui/card/card.component.ts
+++ b/apps/angular/1-projection/src/app/ui/card/card.component.ts
@@ -1,10 +1,12 @@
-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 {
+  ChangeDetectionStrategy,
+  Component,
+  contentChild,
+  input,
+  output,
+} from '@angular/core';
+import { CardItemDirective } from './card-item.directive';
 
 @Component({
   selector: 'app-card',
@@ -12,47 +14,31 @@ 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()">
-      @if (type() === CardType.TEACHER) {
-        <img ngSrc="assets/img/teacher.png" width="200" height="200" alt="" />
-      }
-      @if (type() === CardType.STUDENT) {
-        <img ngSrc="assets/img/student.webp" width="200" height="200" alt="" />
-      }
+      <ng-content select="[card-image]" />
 
       <section>
-        @for (item of list(); track item) {
-          <app-list-item
-            [name]="item.firstName"
-            [id]="item.id"
-            [type]="type()"></app-list-item>
+        @for (item of list(); track $index) {
+          <ng-container
+            [ngTemplateOutlet]="itemTemplate().templateRef"
+            [ngTemplateOutletContext]="{ $implicit: item }" />
         }
       </section>
 
       <button
         class="rounded-sm border border-blue-500 bg-blue-300 p-2"
-        (click)="addNewItem()">
+        (click)="add.emit()">
         Add
       </button>
     </div>
   `,
-  imports: [ListItemComponent, NgOptimizedImage],
+  imports: [NgTemplateOutlet],
+  changeDetection: ChangeDetectionStrategy.OnPush,
 })
-export class CardComponent {
-  private teacherStore = inject(TeacherStore);
-  private studentStore = inject(StudentStore);
-
-  readonly list = input<any[] | null>(null);
-  readonly type = input.required<CardType>();
+export class CardComponent<T> {
+  readonly list = input<readonly T[]>([]);
   readonly customClass = input('');
 
-  CardType = CardType;
+  protected itemTemplate = contentChild.required(CardItemDirective);
 
-  addNewItem() {
-    const type = this.type();
-    if (type === CardType.TEACHER) {
-      this.teacherStore.addOne(randTeacher());
-    } else if (type === CardType.STUDENT) {
-      this.studentStore.addOne(randStudent());
-    }
-  }
+  add = output<void>();
 }
diff --git a/apps/angular/1-projection/src/app/ui/list-item/list-item.component.ts b/apps/angular/1-projection/src/app/ui/list-item/list-item.component.ts
index c04a29c05..b2ad9d3cc 100644
--- a/apps/angular/1-projection/src/app/ui/list-item/list-item.component.ts
+++ b/apps/angular/1-projection/src/app/ui/list-item/list-item.component.ts
@@ -1,19 +1,16 @@
 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',
   template: `
     <div class="flex justify-between border border-gray-300 px-2 py-1">
       {{ name() }}
-      <button (click)="delete(id())">
+      <button (click)="delete.emit(id())">
         <img class="h-5" src="assets/svg/trash.svg" alt="trash" />
       </button>
     </div>
@@ -21,19 +18,8 @@ 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>();
 
-  delete(id: number) {
-    const type = this.type();
-    if (type === CardType.TEACHER) {
-      this.teacherStore.deleteOne(id);
-    } else if (type === CardType.STUDENT) {
-      this.studentStore.deleteOne(id);
-    }
-  }
+  delete = output<number>();
 }