import { Injectable } from '@angular/core' ; import { HttpClient , HttpHeaders } from "@angular/common/http" ; const httpOptions = { headers : new HttpHeaders ( { "Content-Type" : "application/json" } ) , } ; @ Injectable ( { providedIn : 'root' } ) export class DatabaseService { constructor ( private http ) { } public initial ( ) { return this . http . get ( '/initial' ) ; } }