Filter items from Firebase branch (SWIFT) - swift

Question

Current user in App tap the Like button on post (audio record) from another user and it appears in likes branch in Firebase. There is another branch records, where all records from each users exist.
I've got a Firebase structure
Blue: current userID,
Green: another userID,
Red: recordID.
I need to display on my ViewController only liked records (red line), but with my code I've got all records from another user (green line). How to display only liked records (red line)?
fileprivate func fetchRecordsWithUser(user: User2){
let ref = Database.database().reference().child("records").child(user.uid)
ref.observeSingleEvent(of: .value, with: { (snapshot) in
guard let dictionaries = snapshot.value as? [String: Any] else { return }
dictionaries.forEach({ (key, value) in
guard let dictionary = value as? [String: Any] else { return }
let record = Records(user: user, dictionary: dictionary)
self.records.append(record)
self.records.sort(by: { (p1, p2) -> Bool in
return p1.creationDate.compare(p2.creationDate) == .orderedDescending
})
self.tableView?.reloadData()
})
}) { (err) in
print ("Faild to fetch records:", err)
}
}

Answer 1

I am a little unclear on the question but let me give this a try
Lets's start with a structure like in the question, using simpler data.
likes
uid_0
uid_1
record_0: true
uid_2
record_1: true
uid_1
uid_0
record_3: true
I believe the object is the get the values record_0, record_1 and record_3 so the code to do that is:
func printRecordIds() {
var recordIdArray = [String]()
let likesRef = self.ref.child("likes")
likesRef.observeSingleEvent(of: .value, with: { snapshot in
let allLikes = snapshot.children.allObjects as! [DataSnapshot]
for likeSnap in allLikes {
let uid = likeSnap.key
print(uid)
let uidLikes = likeSnap.children.allObjects as! [DataSnapshot]
for childLike in uidLikes {
let childUid = childLike.key
print(" child uid: \(childUid)")
let childRecords = childLike.children.allObjects as! [DataSnapshot]
for child in childRecords {
let recordId = child.key
print(" recordId: \(recordId)")
recordIdArray.append(recordId)
}
}
for r in recordIdArray {
print(r)
}
}
})
and the output
uid_0
child uid: uid_1
recordId: record_0
child uid: uid_2
recordId: record_1
record_0
record_1
uid_1
child uid: uid_0
recordId: record_3
record_0
record_1
record_3
So the output shows the data we are reading in per node so you can see the flow and then the array, populated with the record id's.