I have two components and 2 services connected to them. First is a ProductComponent
:
@Component({
selector: 'app-product',
templateUrl: './product.component.html',
styleUrls: ['./product.component.css'],
providers: [ProductService, CartService]
})
export class ProductComponent implements OnInit {
private products;
private numberOfItems = 0;
constructor(private productService: ProductService, private cartService: CartService) {
}
ngOnInit() {
this.loadProducts();
}
loadProducts() {
this.productService.getProducts().subscribe(data => this.products = data);
}
addProductToCard(product: Product) {
this.cartService.addProduct(product);
this.numberOfItems = this.cartService.getCartLength();
}
}
I use here CartService
where I saved products I want to buy. All of them are add into cart
list which is defined in CartService
:
@Injectable()
export class CartService {
private cart: Product[] = [];
constructor() {
}
addProduct(product: Product) {
this.cart.push(product);
}
getCart() {
return this.cart;
}
getTotalPrice() {
const totalPrice = this.cart.reduce((sum, cardItem) => {
return sum += cardItem.price, sum;
}, 0);
return totalPrice;
}
getCartLength() {
return this.cart.length;
}
}
export interface Product {
id: number;
name: string;
description: string;
price: number;
amount: number;
}
Now I want to use this filled cart
list in CartComponent
:
@Component({
selector: 'app-card',
templateUrl: './card.component.html',
styleUrls: ['./card.component.css']
})
export class CartComponent implements OnInit {
private cart;
constructor(private cartService: CartService) {
}
ngOnInit() {
this.cart = this.cartService.getCart();
console.log(this.cart.length);
}
}
but it is empty there. I know that probably I inject there new CartService
, not that one I used in ProductComponent
. My question is how to use same instance of CartService
in CartComponent
as I use in ProductComponent
? Or how to share data between this two services? Maybe I should use cache for this but I hope there are other ways to solve this problem.
EDIT: I add html where I call addToProduct()
:
<div class="basket">
On your cart {{numberOfItems}} items
<p><a routerLink="/cart">Go to cart</a></p>
<router-outlet></router-outlet>
</div>
<table class="table table-striped">
<thead class="thead-inverse">
<tr>
<th>#</th>
<th>Name</th>
<th>Desc</th>
<th>Price</th>
<th>Amount</th>
</tr>
</thead>
<tbody *ngFor="let product of products">
<tr>
<th scope="row">{{product.id}}</th>
<td>{{product.name}}</td>
<td>{{product.description}}</td>
<td>{{product.price}}</td>
<td>{{product.amount}}</td>
<button type="button" class="btn btn-success" (click)="addProductToCard(product)">Add to cart</button>
</tr>
</tbody>
</table>
如果要在两个组件中都获得CartService
的相同实例, CartService
必须将其注册为模块级提供程序,而不是单个组件上的提供程序。
Sharing data between services is better approch. Instead use ngrx/store package which is similar to Redux.
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