Ionic spinner while Angularfire Firestore is loading - ionic-framework

Question

In an Ionic project i am using the code below to load a document collection from Firestore with the AngularFirestore wrappers.
Now that the content starts loading when the view was initialized i'm experiencing a delay by about 4-8 seconds until the firestore fetched data renders in my list-view, which is very very bad for the overall userexperience.
with the code below i'm able to show a loading spinner when the content starts loading bit i need it to stop showing the loader.
I have no clue how to trigger that event? Any help would be appreciated
thank you very much
import { City } from './../../model/City';
import { Component, AfterViewInit } from '#angular/core';
import { NavController, IonicPage, LoadingController } from 'ionic-angular';
import { AngularFirestore, AngularFirestoreCollection } from 'angularfire2/firestore';
import { Observable } from 'rxjs/Observable';
#IonicPage()
#Component({
selector: 'page-home',
templateUrl: 'home.html'
})
export class HomePage implements AfterViewInit {
citiesRef: AngularFirestoreCollection<City>
cities: Observable<City[]>;
loading = this.loadingCtrl.create({
content: 'Loading Regions...'
});
constructor(private loadingCtrl: LoadingController, private afs: AngularFirestore, public navCtrl: NavController) {
}
ngAfterViewInit(){
this.loading.present().then(()=>{
this.citiesRef = this.afs.collection<City>('regions', ref => ref.orderBy('name'));
this.cities = this.citiesRef.valueChanges();
})
}
}

Answer 1

Well, what I did was I subscribe to the this.cities. It worked in my case. The idea is it will fire loading.dismiss() once it is able to subscribe. Hope that helps
let loading = this.loadingCtrl.create({
content: 'Please wait...'
});
loading.present();
this.citiesRef=this.afs.collection('cities');
this.cities=this.citiesRef.valueChanges();
this.cities.subscribe(_=>{
loading.dismiss();
})