查询可观察和angularfire2

Question

i'm wondering how can i use angularfire2 to query data an get the list of the queried data and then observer next the data to be able to subscribe to it and pass it into an ngFor loop, for example , how can i transform this sample code below to use angularfire2

load() {
  const messagesObservable = new BehaviorSubject<MessageThread[]>(null)
  this.rootRef.child("users").child(this.currentUserid).child("rooms").on("child_added", snapshot => {
    key = snapshot.key()
    this.rootRef.child("messages").orderByKey().equalTo(key).on("value", snapshot => {
      const data = snapshot.val()
      const Messages = Object.keys(data).map(id => new MessageThread(id))
      MessageThread.next(Messages)
    })
  })
  return Messages
}

Answer 1

I would try something like this:

constructor(private af: AngularFire) {
}

load() {
  return this.af.list(this.rootRef.child("messages")
                   .orderByKey().equalTo(key));
}