From 48012bc381c86b4c23b55ffd607f944be1e17039 Mon Sep 17 00:00:00 2001
From: thomas laforge <toma.laforge@gmail.com>
Date: Sat, 5 Nov 2022 21:39:08 +0100
Subject: [PATCH 1/3] feat(Answer:1): solution projection

---
 .../student-card/student-card.component.ts    | 50 ++++++-----
 .../teacher-card/teacher-card.component.ts    | 50 ++++++-----
 .../projection/src/app/model/card.model.ts    |  5 --
 .../src/app/ui/card/card.component.ts         | 83 ++++++++-----------
 .../app/ui/list-item/list-item.component.ts   | 34 +++-----
 5 files changed, 106 insertions(+), 116 deletions(-)

diff --git a/apps/angular/projection/src/app/component/student-card/student-card.component.ts b/apps/angular/projection/src/app/component/student-card/student-card.component.ts
index 441cda189..62850a395 100644
--- a/apps/angular/projection/src/app/component/student-card/student-card.component.ts
+++ b/apps/angular/projection/src/app/component/student-card/student-card.component.ts
@@ -1,40 +1,52 @@
-import { Component, OnInit } from '@angular/core';
-import { FakeHttpService } from '../../data-access/fake-http.service';
+import { AsyncPipe } from '@angular/common';
+import { ChangeDetectionStrategy, Component, OnInit } from '@angular/core';
+import {
+  FakeHttpService,
+  randStudent,
+} from '../../data-access/fake-http.service';
 import { StudentStore } from '../../data-access/student.store';
-import { CardType } from '../../model/card.model';
-import { Student } from '../../model/student.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"></app-card>
-  `,
+  template: `<app-card
+    [list]="students$ | async"
+    (add)="addStudent()"
+    class="bg-light-green"
+  >
+    <img src="assets/img/student.webp" width="200px" />
+    <ng-template #rowRef let-student>
+      <app-list-item (delete)="deleteStudent(student.id)">
+        {{ student.firstname }}
+      </app-list-item>
+    </ng-template>
+  </app-card>`,
   standalone: true,
   styles: [
     `
-      ::ng-deep .bg-light-green {
+      .bg-light-green {
         background-color: rgba(0, 250, 0, 0.1);
       }
     `,
   ],
-  imports: [CardComponent],
+  imports: [CardComponent, ListItemComponent, AsyncPipe],
+  changeDetection: ChangeDetectionStrategy.OnPush,
 })
 export class StudentCardComponent implements OnInit {
-  students: Student[] = [];
-  cardType = CardType.STUDENT;
+  students$ = this.store.students$;
 
-  constructor(
-    private http: FakeHttpService,
-    private store: StudentStore,
-  ) {}
+  constructor(private http: FakeHttpService, private store: StudentStore) {}
 
   ngOnInit(): void {
     this.http.fetchStudents$.subscribe((s) => this.store.addAll(s));
+  }
+
+  addStudent() {
+    this.store.addOne(randStudent());
+  }
 
-    this.store.students$.subscribe((s) => (this.students = s));
+  deleteStudent(id: number) {
+    this.store.deleteOne(id);
   }
 }
diff --git a/apps/angular/projection/src/app/component/teacher-card/teacher-card.component.ts b/apps/angular/projection/src/app/component/teacher-card/teacher-card.component.ts
index 995cb7c2f..8f43b666d 100644
--- a/apps/angular/projection/src/app/component/teacher-card/teacher-card.component.ts
+++ b/apps/angular/projection/src/app/component/teacher-card/teacher-card.component.ts
@@ -1,40 +1,52 @@
-import { Component, OnInit } from '@angular/core';
-import { FakeHttpService } from '../../data-access/fake-http.service';
+import { AsyncPipe } from '@angular/common';
+import { ChangeDetectionStrategy, Component, 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 { Teacher } from '../../model/teacher.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>
-  `,
+  template: `<app-card
+    [list]="teachers$ | async"
+    class="bg-light-red"
+    (add)="addTeacher()"
+  >
+    <img src="assets/img/teacher.png" width="200px" />
+    <ng-template #rowRef let-teacher>
+      <app-list-item (delete)="deleteTeacher(teacher.id)">
+        {{ teacher.firstname }}
+      </app-list-item>
+    </ng-template>
+  </app-card>`,
   styles: [
     `
-      ::ng-deep .bg-light-red {
+      .bg-light-red {
         background-color: rgba(250, 0, 0, 0.1);
       }
     `,
   ],
   standalone: true,
-  imports: [CardComponent],
+  imports: [CardComponent, ListItemComponent, AsyncPipe],
+  changeDetection: ChangeDetectionStrategy.OnPush,
 })
 export class TeacherCardComponent implements OnInit {
-  teachers: Teacher[] = [];
-  cardType = CardType.TEACHER;
+  teachers$ = this.store.teachers$;
 
-  constructor(
-    private http: FakeHttpService,
-    private store: TeacherStore,
-  ) {}
+  constructor(private http: FakeHttpService, private store: TeacherStore) {}
 
   ngOnInit(): void {
     this.http.fetchTeachers$.subscribe((t) => this.store.addAll(t));
+  }
+
+  addTeacher() {
+    this.store.addOne(randTeacher());
+  }
 
-    this.store.teachers$.subscribe((t) => (this.teachers = t));
+  deleteTeacher(id: number) {
+    this.store.deleteOne(id);
   }
 }
diff --git a/apps/angular/projection/src/app/model/card.model.ts b/apps/angular/projection/src/app/model/card.model.ts
index 740cd2ae4..e69de29bb 100644
--- a/apps/angular/projection/src/app/model/card.model.ts
+++ b/apps/angular/projection/src/app/model/card.model.ts
@@ -1,5 +0,0 @@
-export enum CardType {
-  TEACHER,
-  STUDENT,
-  CITY,
-}
diff --git a/apps/angular/projection/src/app/ui/card/card.component.ts b/apps/angular/projection/src/app/ui/card/card.component.ts
index f06c9ae00..be20707e6 100644
--- a/apps/angular/projection/src/app/ui/card/card.component.ts
+++ b/apps/angular/projection/src/app/ui/card/card.component.ts
@@ -1,61 +1,44 @@
-import { NgFor, NgIf } from '@angular/common';
-import { Component, 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 { NgFor, NgIf, NgTemplateOutlet } from '@angular/common';
+import {
+  ChangeDetectionStrategy,
+  Component,
+  ContentChild,
+  EventEmitter,
+  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">
-      <img
-        *ngIf="type === CardType.TEACHER"
-        src="assets/img/teacher.png"
-        width="200px" />
-      <img
-        *ngIf="type === CardType.STUDENT"
-        src="assets/img/student.webp"
-        width="200px" />
+    <ng-content select="img"></ng-content>
 
-      <section>
-        <app-list-item
-          *ngFor="let item of list"
-          [name]="item.firstName"
-          [id]="item.id"
-          [type]="type"></app-list-item>
-      </section>
+    <section>
+      <ng-container *ngFor="let item of list">
+        <ng-template
+          [ngTemplateOutlet]="rowTemplate"
+          [ngTemplateOutletContext]="{ $implicit: item }"></ng-template>
+      </ng-container>
+    </section>
 
-      <button
-        class="rounded-sm border border-blue-500 bg-blue-300 p-2"
-        (click)="addNewItem()">
-        Add
-      </button>
-    </div>
+    <button
+      class="border border-blue-500 bg-blue-300 p-2 rounded-sm"
+      (click)="add.emit()">
+      Add
+    </button>
   `,
   standalone: true,
-  imports: [NgIf, NgFor, ListItemComponent],
+  imports: [NgIf, NgFor, NgTemplateOutlet],
+  host: {
+    class: 'border-2 border-black rounded-md p-4 w-fit flex flex-col gap-3',
+  },
+  changeDetection: ChangeDetectionStrategy.OnPush,
 })
-export class CardComponent {
-  @Input() list: any[] | null = null;
-  @Input() type!: CardType;
-  @Input() customClass = '';
+export class CardComponent<T> {
+  @Input() list: T[] | null = null;
+  @Output() add = new EventEmitter<void>();
 
-  CardType = CardType;
-
-  constructor(
-    private teacherStore: TeacherStore,
-    private studentStore: StudentStore,
-  ) {}
-
-  addNewItem() {
-    if (this.type === CardType.TEACHER) {
-      this.teacherStore.addOne(randTeacher());
-    } else if (this.type === CardType.STUDENT) {
-      this.studentStore.addOne(randStudent());
-    }
-  }
+  @ContentChild('rowRef', { read: TemplateRef })
+  rowTemplate!: TemplateRef<{ $implicit: T }>;
 }
diff --git a/apps/angular/projection/src/app/ui/list-item/list-item.component.ts b/apps/angular/projection/src/app/ui/list-item/list-item.component.ts
index c0f9cff7f..862df5948 100644
--- a/apps/angular/projection/src/app/ui/list-item/list-item.component.ts
+++ b/apps/angular/projection/src/app/ui/list-item/list-item.component.ts
@@ -1,35 +1,23 @@
-import { Component, 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,
+  EventEmitter,
+  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)">
+    <div class="border border-grey-300 py-1 px-2 flex justify-between">
+      <ng-content></ng-content>
+      <button (click)="delete.next()">
         <img class="h-5" src="assets/svg/trash.svg" />
       </button>
     </div>
   `,
   standalone: true,
+  changeDetection: ChangeDetectionStrategy.OnPush,
 })
 export class ListItemComponent {
-  @Input() id!: number;
-  @Input() name!: string;
-  @Input() type!: CardType;
-
-  constructor(
-    private teacherStore: TeacherStore,
-    private studentStore: StudentStore,
-  ) {}
-
-  delete(id: number) {
-    if (this.type === CardType.TEACHER) {
-      this.teacherStore.deleteOne(id);
-    } else if (this.type === CardType.STUDENT) {
-      this.studentStore.deleteOne(id);
-    }
-  }
+  @Output() delete = new EventEmitter<void>();
 }

From cfdc8f0ba13d5e55b0498551a4116a41718c210f Mon Sep 17 00:00:00 2001
From: thomas <toma.laforge@gmail.com>
Date: Sun, 14 Apr 2024 22:18:12 +0200
Subject: [PATCH 2/3] feat: update solution

---
 .../teacher-card/teacher-card.component.ts    | 32 ++++++++++---------
 .../src/app/data-access/teacher.store.ts      | 12 +++----
 .../src/app/ui/card/card-row.directive.ts     |  4 +++
 .../src/app/ui/card/card.component.ts         | 31 +++++++++---------
 .../app/ui/list-item/list-item.component.ts   | 15 +++------
 5 files changed, 46 insertions(+), 48 deletions(-)
 create mode 100644 apps/angular/projection/src/app/ui/card/card-row.directive.ts

diff --git a/apps/angular/projection/src/app/component/teacher-card/teacher-card.component.ts b/apps/angular/projection/src/app/component/teacher-card/teacher-card.component.ts
index 8f43b666d..a04f17453 100644
--- a/apps/angular/projection/src/app/component/teacher-card/teacher-card.component.ts
+++ b/apps/angular/projection/src/app/component/teacher-card/teacher-card.component.ts
@@ -5,23 +5,22 @@ import {
   randTeacher,
 } from '../../data-access/fake-http.service';
 import { TeacherStore } from '../../data-access/teacher.store';
+import { CardRowDirective } from '../../ui/card/card-row.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$ | async"
-    class="bg-light-red"
-    (add)="addTeacher()"
-  >
-    <img src="assets/img/teacher.png" width="200px" />
-    <ng-template #rowRef let-teacher>
-      <app-list-item (delete)="deleteTeacher(teacher.id)">
-        {{ teacher.firstname }}
-      </app-list-item>
-    </ng-template>
-  </app-card>`,
+  template: `
+    <app-card [items]="teachers()" class="bg-light-red" (add)="addTeacher()">
+      <img src="assets/img/teacher.png" width="200px" />
+      <ng-template cardRow let-teacher>
+        <app-list-item (delete)="deleteTeacher(teacher.id)">
+          {{ teacher.firstname }}
+        </app-list-item>
+      </ng-template>
+    </app-card>
+  `,
   styles: [
     `
       .bg-light-red {
@@ -30,13 +29,16 @@ import { ListItemComponent } from '../../ui/list-item/list-item.component';
     `,
   ],
   standalone: true,
-  imports: [CardComponent, ListItemComponent, AsyncPipe],
+  imports: [ListItemComponent, AsyncPipe, CardRowDirective, CardComponent],
   changeDetection: ChangeDetectionStrategy.OnPush,
 })
 export class TeacherCardComponent implements OnInit {
-  teachers$ = this.store.teachers$;
+  teachers = this.store.teachers;
 
-  constructor(private http: FakeHttpService, private store: TeacherStore) {}
+  constructor(
+    private http: FakeHttpService,
+    private store: TeacherStore,
+  ) {}
 
   ngOnInit(): void {
     this.http.fetchTeachers$.subscribe((t) => this.store.addAll(t));
diff --git a/apps/angular/projection/src/app/data-access/teacher.store.ts b/apps/angular/projection/src/app/data-access/teacher.store.ts
index 93f68c4b1..c30b6e0ec 100644
--- a/apps/angular/projection/src/app/data-access/teacher.store.ts
+++ b/apps/angular/projection/src/app/data-access/teacher.store.ts
@@ -1,23 +1,21 @@
-import { Injectable } from '@angular/core';
-import { BehaviorSubject } from 'rxjs';
+import { Injectable, signal } from '@angular/core';
 import { Teacher } from '../model/teacher.model';
 
 @Injectable({
   providedIn: 'root',
 })
 export class TeacherStore {
-  private teachers = new BehaviorSubject<Teacher[]>([]);
-  teachers$ = this.teachers.asObservable();
+  teachers = signal<Teacher[]>([]);
 
   addAll(teachers: Teacher[]) {
-    this.teachers.next(teachers);
+    this.teachers.set(teachers);
   }
 
   addOne(teacher: Teacher) {
-    this.teachers.next([...this.teachers.value, teacher]);
+    this.teachers.set([...this.teachers(), teacher]);
   }
 
   deleteOne(id: number) {
-    this.teachers.next(this.teachers.value.filter((t) => t.id !== id));
+    this.teachers.set(this.teachers().filter((t) => t.id !== id));
   }
 }
diff --git a/apps/angular/projection/src/app/ui/card/card-row.directive.ts b/apps/angular/projection/src/app/ui/card/card-row.directive.ts
new file mode 100644
index 000000000..551cc0406
--- /dev/null
+++ b/apps/angular/projection/src/app/ui/card/card-row.directive.ts
@@ -0,0 +1,4 @@
+import { Directive } from '@angular/core';
+
+@Directive({ selector: 'ng-template[cardRow]', standalone: true })
+export class CardRowDirective {}
diff --git a/apps/angular/projection/src/app/ui/card/card.component.ts b/apps/angular/projection/src/app/ui/card/card.component.ts
index be20707e6..499ef670e 100644
--- a/apps/angular/projection/src/app/ui/card/card.component.ts
+++ b/apps/angular/projection/src/app/ui/card/card.component.ts
@@ -1,44 +1,43 @@
-import { NgFor, NgIf, NgTemplateOutlet } from '@angular/common';
+import { NgTemplateOutlet } from '@angular/common';
 import {
   ChangeDetectionStrategy,
   Component,
-  ContentChild,
-  EventEmitter,
-  Input,
-  Output,
+  contentChild,
+  input,
+  output,
   TemplateRef,
 } from '@angular/core';
+import { CardRowDirective } from './card-row.directive';
 
 @Component({
   selector: 'app-card',
   template: `
-    <ng-content select="img"></ng-content>
+    <ng-content select="img" />
 
     <section>
-      <ng-container *ngFor="let item of list">
+      @for (item of items(); track item.id) {
         <ng-template
-          [ngTemplateOutlet]="rowTemplate"
+          [ngTemplateOutlet]="rowTemplate()"
           [ngTemplateOutletContext]="{ $implicit: item }"></ng-template>
-      </ng-container>
+      }
     </section>
 
     <button
-      class="border border-blue-500 bg-blue-300 p-2 rounded-sm"
+      class="rounded-sm border border-blue-500 bg-blue-300 p-2"
       (click)="add.emit()">
       Add
     </button>
   `,
   standalone: true,
-  imports: [NgIf, NgFor, NgTemplateOutlet],
+  imports: [NgTemplateOutlet],
   host: {
     class: 'border-2 border-black rounded-md p-4 w-fit flex flex-col gap-3',
   },
   changeDetection: ChangeDetectionStrategy.OnPush,
 })
-export class CardComponent<T> {
-  @Input() list: T[] | null = null;
-  @Output() add = new EventEmitter<void>();
+export class CardComponent<T extends { id: number }> {
+  items = input.required<T[]>();
+  add = output();
 
-  @ContentChild('rowRef', { read: TemplateRef })
-  rowTemplate!: TemplateRef<{ $implicit: T }>;
+  rowTemplate = contentChild.required(CardRowDirective, { read: TemplateRef });
 }
diff --git a/apps/angular/projection/src/app/ui/list-item/list-item.component.ts b/apps/angular/projection/src/app/ui/list-item/list-item.component.ts
index 862df5948..45b1f7a78 100644
--- a/apps/angular/projection/src/app/ui/list-item/list-item.component.ts
+++ b/apps/angular/projection/src/app/ui/list-item/list-item.component.ts
@@ -1,16 +1,11 @@
-import {
-  ChangeDetectionStrategy,
-  Component,
-  EventEmitter,
-  Output,
-} from '@angular/core';
+import { ChangeDetectionStrategy, Component, output } from '@angular/core';
 
 @Component({
   selector: 'app-list-item',
   template: `
-    <div class="border border-grey-300 py-1 px-2 flex justify-between">
-      <ng-content></ng-content>
-      <button (click)="delete.next()">
+    <div class="border-grey-300 flex justify-between border px-2 py-1">
+      <ng-content />
+      <button (click)="delete.emit()">
         <img class="h-5" src="assets/svg/trash.svg" />
       </button>
     </div>
@@ -19,5 +14,5 @@ import {
   changeDetection: ChangeDetectionStrategy.OnPush,
 })
 export class ListItemComponent {
-  @Output() delete = new EventEmitter<void>();
+  delete = output<void>();
 }

From 5f5140fb0b89faac4282402e3968cf24dcf837a2 Mon Sep 17 00:00:00 2001
From: thomas <toma.laforge@gmail.com>
Date: Sun, 14 Apr 2024 22:39:40 +0200
Subject: [PATCH 3/3] feat: update projection solution

---
 .../student-card/student-card.component.ts    | 36 +++++++++----------
 .../teacher-card/teacher-card.component.ts    | 18 +++++-----
 .../src/app/data-access/student.store.ts      | 12 +++----
 .../src/app/ui/card/card-row.directive.ts     | 17 +++++++--
 4 files changed, 46 insertions(+), 37 deletions(-)

diff --git a/apps/angular/projection/src/app/component/student-card/student-card.component.ts b/apps/angular/projection/src/app/component/student-card/student-card.component.ts
index 62850a395..569e6d6af 100644
--- a/apps/angular/projection/src/app/component/student-card/student-card.component.ts
+++ b/apps/angular/projection/src/app/component/student-card/student-card.component.ts
@@ -1,27 +1,26 @@
 import { AsyncPipe } from '@angular/common';
-import { ChangeDetectionStrategy, Component, OnInit } from '@angular/core';
+import { ChangeDetectionStrategy, Component, inject } from '@angular/core';
 import {
   FakeHttpService,
   randStudent,
 } from '../../data-access/fake-http.service';
 import { StudentStore } from '../../data-access/student.store';
+import { CardRowDirective } from '../../ui/card/card-row.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$ | async"
-    (add)="addStudent()"
-    class="bg-light-green"
-  >
-    <img src="assets/img/student.webp" width="200px" />
-    <ng-template #rowRef let-student>
-      <app-list-item (delete)="deleteStudent(student.id)">
-        {{ student.firstname }}
-      </app-list-item>
-    </ng-template>
-  </app-card>`,
+  template: `
+    <app-card [items]="students()" (add)="addStudent()" class="bg-light-green">
+      <img src="assets/img/student.webp" width="200px" />
+      <ng-template [cardRow]="students()" let-student>
+        <app-list-item (delete)="deleteStudent(student.id)">
+          {{ student.firstName }}
+        </app-list-item>
+      </ng-template>
+    </app-card>
+  `,
   standalone: true,
   styles: [
     `
@@ -30,15 +29,16 @@ import { ListItemComponent } from '../../ui/list-item/list-item.component';
       }
     `,
   ],
-  imports: [CardComponent, ListItemComponent, AsyncPipe],
+  imports: [CardComponent, ListItemComponent, AsyncPipe, CardRowDirective],
   changeDetection: ChangeDetectionStrategy.OnPush,
 })
-export class StudentCardComponent implements OnInit {
-  students$ = this.store.students$;
+export class StudentCardComponent {
+  private http = inject(FakeHttpService);
+  private store = inject(StudentStore);
 
-  constructor(private http: FakeHttpService, private store: StudentStore) {}
+  students = this.store.students;
 
-  ngOnInit(): void {
+  constructor() {
     this.http.fetchStudents$.subscribe((s) => this.store.addAll(s));
   }
 
diff --git a/apps/angular/projection/src/app/component/teacher-card/teacher-card.component.ts b/apps/angular/projection/src/app/component/teacher-card/teacher-card.component.ts
index a04f17453..ed18d3fd2 100644
--- a/apps/angular/projection/src/app/component/teacher-card/teacher-card.component.ts
+++ b/apps/angular/projection/src/app/component/teacher-card/teacher-card.component.ts
@@ -1,5 +1,5 @@
 import { AsyncPipe } from '@angular/common';
-import { ChangeDetectionStrategy, Component, OnInit } from '@angular/core';
+import { ChangeDetectionStrategy, Component, inject } from '@angular/core';
 import {
   FakeHttpService,
   randTeacher,
@@ -14,9 +14,9 @@ import { ListItemComponent } from '../../ui/list-item/list-item.component';
   template: `
     <app-card [items]="teachers()" class="bg-light-red" (add)="addTeacher()">
       <img src="assets/img/teacher.png" width="200px" />
-      <ng-template cardRow let-teacher>
+      <ng-template [cardRow]="teachers()" let-teacher>
         <app-list-item (delete)="deleteTeacher(teacher.id)">
-          {{ teacher.firstname }}
+          {{ teacher.firstName }}
         </app-list-item>
       </ng-template>
     </app-card>
@@ -32,15 +32,13 @@ import { ListItemComponent } from '../../ui/list-item/list-item.component';
   imports: [ListItemComponent, AsyncPipe, CardRowDirective, CardComponent],
   changeDetection: ChangeDetectionStrategy.OnPush,
 })
-export class TeacherCardComponent implements OnInit {
-  teachers = this.store.teachers;
+export class TeacherCardComponent {
+  private http = inject(FakeHttpService);
+  private store = inject(TeacherStore);
 
-  constructor(
-    private http: FakeHttpService,
-    private store: TeacherStore,
-  ) {}
+  teachers = this.store.teachers;
 
-  ngOnInit(): void {
+  constructor() {
     this.http.fetchTeachers$.subscribe((t) => this.store.addAll(t));
   }
 
diff --git a/apps/angular/projection/src/app/data-access/student.store.ts b/apps/angular/projection/src/app/data-access/student.store.ts
index 7918118c3..47e748162 100644
--- a/apps/angular/projection/src/app/data-access/student.store.ts
+++ b/apps/angular/projection/src/app/data-access/student.store.ts
@@ -1,23 +1,21 @@
-import { Injectable } from '@angular/core';
-import { BehaviorSubject } from 'rxjs';
+import { Injectable, signal } from '@angular/core';
 import { Student } from '../model/student.model';
 
 @Injectable({
   providedIn: 'root',
 })
 export class StudentStore {
-  private students = new BehaviorSubject<Student[]>([]);
-  students$ = this.students.asObservable();
+  students = signal<Student[]>([]);
 
   addAll(students: Student[]) {
-    this.students.next(students);
+    this.students.set(students);
   }
 
   addOne(student: Student) {
-    this.students.next([...this.students.value, student]);
+    this.students.set([...this.students(), student]);
   }
 
   deleteOne(id: number) {
-    this.students.next(this.students.value.filter((s) => s.id !== id));
+    this.students.set(this.students().filter((s) => s.id !== id));
   }
 }
diff --git a/apps/angular/projection/src/app/ui/card/card-row.directive.ts b/apps/angular/projection/src/app/ui/card/card-row.directive.ts
index 551cc0406..ce3d637cb 100644
--- a/apps/angular/projection/src/app/ui/card/card-row.directive.ts
+++ b/apps/angular/projection/src/app/ui/card/card-row.directive.ts
@@ -1,4 +1,17 @@
-import { Directive } from '@angular/core';
+import { Directive, input } from '@angular/core';
+
+interface CardRowContext<T> {
+  $implicit: T;
+}
 
 @Directive({ selector: 'ng-template[cardRow]', standalone: true })
-export class CardRowDirective {}
+export class CardRowDirective<T> {
+  cardRow = input.required<T[]>();
+
+  static ngTemplateContextGuard<TContext>(
+    dir: CardRowDirective<TContext>,
+    ctx: unknown,
+  ): ctx is CardRowContext<TContext> {
+    return true;
+  }
+}