Overriding providers in the injector hierarchy
We have already learned how to use the providers property in an Angular decorator:
@Component({
selector: 'app-product-list',
templateUrl: './product-list.component.html',
styleUrls: ['./product-list.component.css'],
providers: [ProductsService]
})The preceding syntax is called class provider syntax and is shorthand for the provide object literal syntax shown below:
@Component({
selector: 'app-product-list',
templateUrl: './product-list.component.html',
styleUrls: ['./product-list.component.css'],
providers: [
{ provide: ProductsService, useClass: ProductsService }
]
})The provide object literal syntax consists of two properties:
provide: It is the token that's used to configure the injector. It is the actual class that consumers of the dependency inject into their constructors.useClass: It is the actual implementation...