Fetched data from Firestore returns duplicates - swift

Question

I am trying to fetch data from firebase firestore. The problem i have is that my fetch is returning the results x4 times. For example when i do print(name) it print the users name x4 times.
I think there may be a loop that is not working correctly?
// fetches and returns all conversations for the user with passed in uid
public func getAllConversations(for uid: String, completion: #escaping(Result<[Conversation], Error>) -> Void) {
let CurrentUser = Auth.auth().currentUser?.uid
let db = Firestore.firestore()
let ConversationRef = db.collection("users").document(CurrentUser!).collection("conversations").document(
"jVymlfbpuAYQQ9Brf8SbUZ7KCGg1")
// get the otherUserUId TO DO
ConversationRef.getDocument { snapshot, error in
if error != nil {
print("Error connecting to database")
} else {
if let document = snapshot {
if document.exists {
let data = document.data()
print(data)
let conversations: [Conversation] = data!.compactMap ({ dictionary in
guard let conversationId = data!["id"] as? String,
let name = data!["name"] as? String,
let otherUserUid = data!["other_user-uid"] as? String,
let latestMessage = data!["latest-message"] as? [String:Any],
let date = latestMessage["date"] as? String,
let message = latestMessage["message"] as? String,
let isRead = latestMessage["is-read"] as? Bool
else {
return nil
}
print(name)
let latestMessageObject = LatestMessage(date: date, text: message, isRead: isRead)
return Conversation(id: conversationId, name: name, otherUserUid: otherUserUid, latestMessage: latestMessageObject)
})
completion(.success(conversations))
}
else {
completion(.failure(DatabaseError.failedToFetch))
return
}
}
}
}
}

Answer 1

Please note that ConversationRef.getDocument{..} will only Return One Specific Document, which you’re Referring here :
let ConversationRef = db.collection("users").document(CurrentUser!).collection("conversations").document("jVymlfbpuAYQQ9Brf8SbUZ7KCGg1”)
So the let data = document.data()
will be single [String:Any] object(in this case Single ‘Conversation’),
not the Array of Dictionaries(eg: [Conversations]).
Try doing it this way:
// fetches and returns all conversations for the user with passed in uid
public func getAllConversations(for uid: String, completion: #escaping(Result<Conversation, Error>) -> Void) {
let CurrentUser = Auth.auth().currentUser?.uid
let db = Firestore.firestore()
let ConversationRef = db.collection("users").document(CurrentUser!).collection("conversations").document(
"jVymlfbpuAYQQ9Brf8SbUZ7KCGg1")
// get the otherUserUId TO DO
ConversationRef.getDocument { snapshot, error in
if error != nil {
print("Error connecting to database")
} else {
if let document = snapshot {
if document.exists {
if let data = document.data() {
if let conversationId = data["id"] as? String,
let name = data["name"] as? String,
let otherUserUid = data["other_user-uid"] as? String,
let latestMessage = data["latest-message"] as? [String:Any],
let date = latestMessage["date"] as? String,
let message = latestMessage["message"] as? String,
let isRead = latestMessage["is-read"] as? Bool {
print(name)
let latestMessageObject = LatestMessage(date: date, text: message, isRead: isRead)
let conversations = Conversation(id: conversationId, name: name, otherUserUid: otherUserUid, latestMessage: latestMessageObject)
completion(.success(conversations))
}
}
}
else {
completion(.failure(DatabaseError.failedToFetch))
return
}
}
}
}
}

Answer 2

// fetches and returns all conversations for the user with passed in uid
public func getAllConversations(for uid: String, completion: #escaping(Result<[Conversation], Error>) -> Void) {
let CurrentUser = Auth.auth().currentUser?.uid
let db = Firestore.firestore()
let ConversationRef = db.collection("users").document(CurrentUser!).collection("conversations")
ConversationRef.addSnapshotListener { snapshot, error in
if error != nil {
print("Error connecting to database")
} else {
guard let snap = snapshot else {
completion(.failure(DatabaseError.failedToFetch))
return
}
for document in snap.documents {
let data = document.data()
print(data)
guard let conversationId = data["id"] as? String,
let name = data["name"] as? String,
let otherUserUid = data["other_user-uid"] as? String,
let latestMessage = data["latest-message"] as? [String:Any],
let date = latestMessage["date"] as? String,
let message = latestMessage["message"] as? String,
let isRead = latestMessage["is-read"] as? Bool else {
return
}
print(name)
let latestMessageObject = LatestMessage(date: date, text: message, isRead: isRead)
let conversations = [Conversation(id: conversationId, name: name, otherUserUid: otherUserUid, latestMessage: latestMessageObject)]
completion(.success(conversations))
}
}
}
}