import { Component , OnInit } from '@angular/core' ; import { AngularFireDatabase } from '@angular/fire/compat/database' ; import { EMPTY , Observable } from 'rxjs' ; import { trace } from '@angular/fire/compat/performance' ; @ Component ( { selector : 'app-database' , template : `
    <p>
      Database!
      {{ testObjectValue$ | async | json }}
    </p>
  ` , styles : [ ] } ) export class DatabaseComponent implements OnInit { public readonly testObjectValue$ : Observable < any > ; constructor ( database ) { const doc = database . object ( 'test' ) ; this . testObjectValue$ = doc . valueChanges ( ) . pipe ( trace ( 'database' ) ) ; } ngOnInit ( ) { } }