All datasources done. Now to wire them up in the components.

Plus ElementRefs are now optional as they cannot be initialized

overlord/src/app/product/product-detail/product-detail.component.ts

@@ -15,7 +15,7 @@ import { ProductService } from '../product.service';
   styleUrls: ['./product-detail.component.css'],
 })
 export class ProductDetailComponent implements OnInit, AfterViewInit {
-  @ViewChild('nameElement', { static: true }) nameElement: ElementRef;
+  @ViewChild('nameElement', { static: true }) nameElement?: ElementRef;
   form: FormGroup;
   productGroups: ProductGroup[];
   item: Product;