iOS: Firebase retrieves old values when persistence is enabled [duplicate]

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• Firebase Offline Capabilities and addListenerForSingleValueEvent 1 answer

I am trying to retrieve the timestamp of the last child in chatRef. It works fine when persistence is disabled. When it is enabled it returns an object in between instead of the last one.

How is this possible?

       self.chatRef.queryOrderedByChild("timestamp").queryLimitedToLast(1).observeSingleEventOfType(.Value, withBlock: { (snapshot) -> Void in
            for child in snapshot.children {

                let childSnapshot = snapshot.childSnapshotForPath(child.key!!)

                if let object = childSnapshot.value as? [String: AnyObject] {
                    var timestamp = (object["timestamp"] as? NSNumber)!.longLongValue 
                    timestampQueryValue = NSNumber(longLong: timestamp)
                    print("timestamp of childSnapshot: (timestampQueryValue)") 
                    // actually prints the timestamp of an older object when persistence is enabled
                }
            }
        })
    }