Terminating app due to uncaught exception 'NSUnknownKeyException' when updating Firebase - swift

Question

When creating a function to add a key-value pair in Firebase I get a crash with the following report
* Terminating app due to uncaught exception 'NSUnknownKeyException', reason: '[ valueForUndefinedKey:]: this class is not key value coding-compliant for the key score.'
* First throw call stack:
(0x1dbd9a3a8 0x1daf9fd00 0x1dbcb36c8 0x1dc796054 0x1dc7ed2a0 0x1dc7070e0 0x102e58cc8 0x102e50640 0x102e4ed18 0x102e4f2c8 0x103f24214 0x103f13f84 0x1daf9b760 0x20906dbf0 0x208af1f94 0x208af22c8 0x208af12dc 0x2090a6a90 0x2090a7cc8 0x209086f50 0x209152150 0x20915490c 0x209154c7c 0x20914d9c4 0x1dbd2a444 0x1dbd2a3c0 0x1dbd29c7c 0x1dbd24950 0x1dbd24254 0x1ddf63d8c 0x20906c4c0 0x102f2befc 0x1db7e0fd8)
libc++abi.dylib: terminating with uncaught exception of type NSException
Message from debugger: failed to send the k packet
The layout of my database is as such:
I believe the problem is I'm calling it to the wrong path in my function.
My functions to update the "score" is :
func updateRecentScore(chatRoomId: String, score: Int) {
let date = dateFormatter().string(from: Date())
firebase.child(kRECENT).queryOrdered(byChild: kCHATROOMID).queryEqual(toValue: chatRoomId).observeSingleEvent(of: .value) { (snapshot) in
if snapshot.exists() {
for recent in ((snapshot.value as! NSDictionary).allValues as Array) {
updateRecentScoreItem(recent: recent as! NSDictionary, score: score)
}
}
}
}
func updateRecentScoreItem(recent: NSDictionary, score: Int) {
var score = recent[kSCORE] as! Int
let values = [kSCORE: score] as [String: Any]
firebase.child(kRECENT).child((recent[kRECENTID] as? String)!).updateChildValues(values as [NSObject : AnyObject]) {
(error, ref) -> Void in
if error != nil {
ProgressHUD.showError("Couldnt update recent: \(error!.localizedDescription)")
}
}
}
I call the function to update it here:
let score = recentsRef.child(kRECENTID).value(forKey: kSCORE) as? Int
let newScore = score! + 1
let score1 = firebase.child(kRECENT).queryOrdered(byChild: kCHATROOMID).queryEqual(toValue: chatRoomId).value(forKey: kSCORE) as? Int
let newScore1 = score1! + 1
updateRecentScore(chatRoomId: chatRoomId, score: newScore1)
All help is appreciated as I'm not sure what to do to fix this and I have tried to look everywhere for an answer. If you need any further information please ask.

Answer 1

I think you're looking for this:
func updateRecentScore(chatRoomId: String, score: Int) {
let date = dateFormatter().string(from: Date())
firebase.child(kRECENT).queryOrdered(byChild: kCHATROOMID).queryEqual(toValue: chatRoomId).observeSingleEvent(of: .value) { (snapshot) in
if let snapshots = snapshot.children.allObjects as? [DataSnapshot] {
for child in snapshots {
child.ref.child(kSCORE).setValue(score+1)
}
}
}
}
The main differences:
I loop over the child nodes with the built-in children property, which means I get a Snapshot, which allows me to simply look up the ref of each child.
I call setValue() directly on the score property, since you're only updating that property. Using updateChildValues is really only useful if you want to update multiple-but-not-all properties in one go.