import { HttpClient } from '@angular/common/http';
import { Injectable } from '@angular/core';
import { ReplaySubject, Observable, tap } from 'rxjs';

@Injectable({
providedIn: 'root'
})
export class CacheService {

private cache$: ReplaySubject = new ReplaySubject(1);

constructor(private http: HttpClient) { }

getData(dataUrl: string): Observable {
// return this.http.get(dataUrl)
if (!this.cache$.observers.length) {
this.http.get(dataUrl)
.pipe(
tap(data => this.cache$.next(data)),
tap(()=>{
console.log(this.cache$)
})
)
.subscribe();
}
return this.cache$.asObservable();
}
}