feat(product-selection): add loading state during product fetch

src/app/product-quantity/product-quantity.component.html

@@ -1 +1 @@
-<input type="number" [ngModel]="quantity" (ngModelChange)="onQuantityChange($event)" [disabled]="!product" min="1">
+<input type="number" [ngModel]="quantity" (ngModelChange)="onQuantityChange($event)" [disabled]="!product" min="1">

src/app/product-quantity/product-quantity.component.ts

@@ -1,4 +1,4 @@
-import { ChangeDetectionStrategy, Component, EventEmitter, Input, Output } from '@angular/core';
+import { ChangeDetectionStrategy, Component, EventEmitter, Input, Output, signal } from '@angular/core';
 import { Product } from '../product-selection/product-selection.component';
 import { FormsModule } from '@angular/forms';
 import { ProductService } from '../services/product.service';
@@ -11,6 +11,7 @@ import { ProductService } from '../services/product.service';
   changeDetection: ChangeDetectionStrategy.OnPush,
 })
 export class ProductQuantityComponent {
+
   @Input({ required: true }) set product(value: Product | null) {
     this.productService.setProduct(value);
   }

src/app/product-selection/product-selection.component.html

@@ -1,4 +1,8 @@
-<select [ngModel]="selectedProduct()" (ngModelChange)="onProductChange($event)">
-  <option [ngValue]="null">Select a product</option>
-  <option *ngFor="let product of products()" [ngValue]="product">{{ product.title }} - {{ product.price | currency : 'EUR' : 'symbol' : '1.2-2' }}</option>
+<ng-container *ngIf="isProductLoading()">
+  <div>Loading...</div>
+</ng-container>
+<ng-container *ngIf="!isProductLoading()">
+  <select [ngModel]="selectedProduct()" (ngModelChange)="onProductChange($event)">
+    <option [ngValue]="null">Select a product</option>
+    <option *ngFor="let product of products()" [ngValue]="product">{{ product.title }} - {{ product.price | currency : 'EUR' : 'symbol' : '1.2-2' }}</option>
 </select>

src/app/product-selection/product-selection.component.ts

@@ -1,4 +1,4 @@
-import { NgFor } from '@angular/common';
+import { NgFor, NgIf } from '@angular/common';
 import { CurrencyPipe } from '@angular/common';
 import { FormsModule } from '@angular/forms';
 import { Component, ChangeDetectionStrategy, Output, EventEmitter, signal, inject, computed, OnInit } from '@angular/core';
@@ -20,7 +20,7 @@ export type Product = {
 @Component({
   selector: 'app-product-selection',
   standalone: true,
-  imports: [NgFor, CurrencyPipe, FormsModule],
+  imports: [NgFor, CurrencyPipe, FormsModule, NgIf],
   templateUrl: './product-selection.component.html',
   changeDetection: ChangeDetectionStrategy.OnPush,
 })
@@ -31,6 +31,8 @@ export class ProductSelectionComponent implements OnInit {
   selectedProduct = signal<Product | null>(null);
 
   quantity = signal<number>(1);
+
+  isProductLoading = signal(true);
   
   @Output() quantityChange = new EventEmitter<number>();
   @Output() productChange = new EventEmitter<Product>();
@@ -38,7 +40,10 @@ export class ProductSelectionComponent implements OnInit {
   private productService = inject(ProductService);
 
   ngOnInit() {
-    this.productService.getProducts().subscribe(products => this.products.set(products));
+    this.productService.getProducts().subscribe(products => {
+      this.products.set(products);
+      this.isProductLoading.set(false);
+    });
   }
 
   onProductChange(selectedProduct: Product) {

src/app/services/product.service.ts

@@ -1,6 +1,6 @@
 import { Injectable, signal, WritableSignal } from '@angular/core';
 import { HttpClient } from '@angular/common/http';
-import { Observable, shareReplay } from 'rxjs';
+import { delay, Observable, shareReplay } from 'rxjs';
 import { Product } from '../product-selection/product-selection.component';
 
 @Injectable({
@@ -12,7 +12,6 @@ export class ProductService {
 
   constructor(private http: HttpClient) {}
 
-  // Local state management
   setProduct(product: Product | null): void {
     this.productSignal.set(product);
     if (product) {
@@ -32,12 +31,15 @@ export class ProductService {
     return this.quantitySignal();
   }
 
-  // API calls
   getProducts(): Observable<any[]> {
-    return this.http.get<any[]>('https://fakestoreapi.com/products');
+    return this.http.get<any[]>('https://fakestoreapi.com/products').pipe(
+      delay(1000)
+    );
   }
 
   getProductById(id: number): Observable<any> {
-    return this.http.get<any>(`https://fakestoreapi.com/products/${id}`);
+    return this.http.get<any>(`https://fakestoreapi.com/products/${id}`).pipe(
+      delay(1000)
+    );
   }
 }