import { HttpClient } from '@angular/common/http'; import { Injectable } from '@angular/core'; import { ReplaySubject } from 'rxjs'; import { MyType } from './my-type'; @Injectable() export class MyService { baseURL = "http://localhost:18674"; // Replay subject: New subscribers will get previous values public nodes = new ReplaySubject<MyType>(); constructor(private http: HttpClient) { // Currently only acquire nodes once this.http.get<MyType>(`${this.baseURL}/api/myapi`).subscribe(value => this.values.next(value); }); } }