feat: resolve projection of Answer:1

Author: al-march

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

@@ -1,13 +1,50 @@
-import { Component, OnInit } from '@angular/core';
+import { Component, OnInit, Signal } from '@angular/core';
+import { toSignal } from '@angular/core/rxjs-interop';
+import { CityStore } from '../../data-access/city.store';
+import {
+  FakeHttpService,
+  randomCity,
+} from '../../data-access/fake-http.service';
+import { City } from '../../model/city.model';
+import { CardComponent } from '../../ui/card/card.component';
+import { ListItemTemplateDirective } from '../../ui/list-item/list-item-template.directive';
+import { ListItemComponent } from '../../ui/list-item/list-item.component';
 
 @Component({
   selector: 'app-city-card',
-  template: 'TODO City',
+  template: `
+    <app-card [list]="cities()" (add)="addCity()">
+      <img src="assets/img/city.png" width="200px" alt="student" />
+
+      <ng-template appListItemTemplate let-city>
+        <app-list-item (deleteItem)="deleteCity(city.id)">
+          {{ city.name }}
+        </app-list-item>
+      </ng-template>
+    </app-card>
+  `,
   standalone: true,
-  imports: [],
+  imports: [CardComponent, ListItemTemplateDirective, ListItemComponent],
 })
 export class CityCardComponent implements OnInit {
-  constructor() {}
+  cities: Signal<City[]> = toSignal(this.store.cities$, {
+    initialValue: [],
+  });
+
+  constructor(
+    private http: FakeHttpService,
+    private store: CityStore,
+  ) {}
+
+  ngOnInit(): void {
+    this.http.fetchCities$.subscribe((s) => this.store.addAll(s));
+  }
+
+  addCity() {
+    this.store.addOne(randomCity());
+  }
 
-  ngOnInit(): void {}
+  deleteCity(id: number) {
+    this.store.deleteOne(id);
+  }
 }

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

@@ -1,31 +1,41 @@
 import { Component, OnInit } from '@angular/core';
-import { FakeHttpService } from '../../data-access/fake-http.service';
+import { toSignal } from '@angular/core/rxjs-interop';
+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 { ListItemTemplateDirective } from '../../ui/list-item/list-item-template.directive';
+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>
+    <app-card class="bg-light-green" [list]="students()" (add)="addStudent()">
+      <img src="assets/img/student.webp" width="200px" alt="student" />
+
+      <ng-template appListItemTemplate let-student>
+        <app-list-item (deleteItem)="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, ListItemTemplateDirective],
 })
 export class StudentCardComponent implements OnInit {
-  students: Student[] = [];
-  cardType = CardType.STUDENT;
+  students = toSignal(this.store.students$, {
+    initialValue: [],
+  });
 
   constructor(
     private http: FakeHttpService,
@@ -34,7 +44,13 @@ export class StudentCardComponent implements OnInit {
 
   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);
   }
 }

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

@@ -1,31 +1,48 @@
-import { Component, OnInit } from '@angular/core';
-import { FakeHttpService } from '../../data-access/fake-http.service';
+import {
+  ChangeDetectionStrategy,
+  Component,
+  OnInit,
+  Signal,
+} from '@angular/core';
+import { toSignal } from '@angular/core/rxjs-interop';
+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 { ListItemTemplateDirective } from '../../ui/list-item/list-item-template.directive';
+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 class="bg-light-red" [list]="teachers()" (add)="addTeacher()">
+      <img src="assets/img/teacher.png" width="200px" alt="teacher" />
+
+      <ng-template appListItemTemplate let-teacher>
+        <app-list-item (deleteItem)="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],
+  changeDetection: ChangeDetectionStrategy.OnPush,
+  imports: [CardComponent, ListItemComponent, ListItemTemplateDirective],
 })
 export class TeacherCardComponent implements OnInit {
-  teachers: Teacher[] = [];
-  cardType = CardType.TEACHER;
+  teachers: Signal<Teacher[]> = toSignal(this.store.teachers$, {
+    initialValue: [],
+  });
 
   constructor(
     private http: FakeHttpService,
@@ -34,7 +51,13 @@ export class TeacherCardComponent implements OnInit {
 
   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);
   }
 }

apps/angular/1-projection/src/app/data-access/city.store.ts

@@ -13,8 +13,8 @@ export class CityStore {
     this.cities.next(cities);
   }
 
-  addOne(student: City) {
-    this.cities.next([...this.cities.value, student]);
+  addOne(city: City) {
+    this.cities.next([...this.cities.value, city]);
   }
 
   deleteOne(id: number) {

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

@@ -1,61 +1,48 @@
-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 { NgTemplateOutlet } from '@angular/common';
+import {
+  ChangeDetectionStrategy,
+  Component,
+  contentChild,
+  input,
+  output,
+} from '@angular/core';
+import { ListItemTemplateDirective } from '../list-item/list-item-template.directive';
 import { ListItemComponent } from '../list-item/list-item.component';
 
 @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" />
 
-      <section>
-        <app-list-item
-          *ngFor="let item of list"
-          [name]="item.firstName"
-          [id]="item.id"
-          [type]="type"></app-list-item>
-      </section>
+    <section>
+      @for (item of list(); track item) {
+        <ng-template
+          [ngTemplateOutlet]="itemTemplate()?.templateRef ?? null"
+          [ngTemplateOutletContext]="{ $implicit: item }" />
+      }
+    </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>
   `,
   standalone: true,
-  imports: [NgIf, NgFor, ListItemComponent],
+  imports: [ListItemComponent, NgTemplateOutlet],
+  changeDetection: ChangeDetectionStrategy.OnPush,
+  host: {
+    class: 'flex w-fit flex-col gap-3 rounded-md border-2 border-black p-4',
+  },
 })
-export class CardComponent {
-  @Input() list: any[] | null = null;
-  @Input() type!: CardType;
-  @Input() customClass = '';
+export class CardComponent<T> {
+  list = input<T[]>([]);
 
-  CardType = CardType;
+  itemTemplate = contentChild(ListItemTemplateDirective);
 
-  constructor(
-    private teacherStore: TeacherStore,
-    private studentStore: StudentStore,
-  ) {}
+  add = output();
 
   addNewItem() {
-    if (this.type === CardType.TEACHER) {
-      this.teacherStore.addOne(randTeacher());
-    } else if (this.type === CardType.STUDENT) {
-      this.studentStore.addOne(randStudent());
-    }
+    this.add.emit();
   }
 }

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

@@ -0,0 +1,9 @@
+import { Directive, TemplateRef } from '@angular/core';
+
+@Directive({
+  selector: '[appListItemTemplate]',
+  standalone: true,
+})
+export class ListItemTemplateDirective {
+  constructor(public templateRef: TemplateRef<unknown>) {}
+}

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

@@ -1,35 +1,20 @@
-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, 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 />
+
+    <button (click)="deleteItem.emit()">
+      <img class="h-5" src="assets/svg/trash.svg" alt="delete" />
+    </button>
   `,
   standalone: true,
+  changeDetection: ChangeDetectionStrategy.OnPush,
+  host: {
+    class: 'border-grey-300 flex justify-between border px-2 py-1',
+  },
 })
 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);
-    }
-  }
+  deleteItem = output();
 }