import { HttpClient } from '@angular/common/http'; import { Injectable } from '@angular/core'; import { Customer } from '../domain/customer'; @Injectable() export class CustomerService { constructor(private http: HttpClient) { } getCustomersSmall() { return this.http.get('assets/demo/data/customers-small.json') .toPromise() .then(res => res.data as Customer[]) .then(data => data); } getCustomersMedium() { return this.http.get('assets/demo/data/customers-medium.json') .toPromise() .then(res => res.data as Customer[]) .then(data => data); } getCustomersLarge() { return this.http.get('assets/demo/data/customers-large.json') .toPromise() .then(res => res.data as Customer[]) .then(data => data); } }