How to retrieve the guest list from an Event

pictures.ts

// First I would create a function in the EventProvider to fetch the guest list

getGuestList(eventId: string): firebase.database.Reference {
  return this.eventListRef.child(eventId).child('guestList');
}

// Then I'd call it from the event's detail page:
public guestList;

ionViewDidLoad(){
  ...
  this.eventProvider.getGuestList(this.navParams.get('eventId'))
    .on('value', eventListSnapshot => {
      this.guestList.push(eventListSnapshot.val());
    });
}

// Then you can fetch the guest list from the HTML page, something like this:

<ion-list>
  <ion-item *ngFor="let guest of guestList">
    <ion-avatar item-start>
      <img [src]="guest.profilePicture">
    </ion-avatar>
    <h2>{{ guest.guestName }}</h2>
  </ion-item>
</ion-list>