import { Injectable } from '@angular/core'; import { ActivatedRouteSnapshot } from '@angular/router'; import { Observable } from 'rxjs/internal/Observable'; import { Voucher } from '../core/voucher'; import { VoucherService } from '../core/voucher.service'; @Injectable({ providedIn: 'root', }) export class PurchaseReturnResolver { constructor(private ser: VoucherService) {} resolve(route: ActivatedRouteSnapshot): Observable { const id = route.paramMap.get('id'); if (id === null) { return this.ser.getOfType('Purchase Return'); } return this.ser.get(id, 'Purchase Return'); } }