SwiftUI - assign Firbase Database output to Data Model - ios

Question

im new to swift and Firebase. And im trying to understand it.
I have a Cloud Firestore DB, where i store some user data like username and email. Now i want the output of the given User assign to my UserData Model for easy use. i really dont know how to achiev this.
These are my two Files:
User.swift
import SwiftUI
import Firebase
import FirebaseFirestore
struct User {
var username : String
var email : String
}
GetData.swift
let docRef = db.collection("users").document(Auth.auth().currentUser?.uid)
docRef.getDocument { (document, error) in
if let document = document, document.exists {
let dataDescription = document.data().map(String.init(describing:)) ?? "nil"
print("Document data: \(dataDescription)")
} else {
print("Document does not exist")
}
}
The Variable dataDescription is givin me a dictonaryArray, with all the needed values. And now i need to assign that Dictonary to my User.swift struct.
best regards!
fYI: Firebase Printscreen

Answer 1

I'd recommend using Codable where you can. I'm using the CodableFirebase Cocoapod to help with Firebase parsing. Below is an example how to use this:
let docRef = db.collection("users").document(Auth.auth().currentUser?.uid)
docRef.getDocument { (document, error) in
guard let value = document.value, value as? NSNull == nil else {
return
}
do {
let newValue = try self.decoder.decode(User.self, from: value)
///New value created here
} catch let error {
print(error)
}
}
You can make this more generic by passing through a class type and having an optional instance returned:
static func item<T: Codable>(_ item: T.Type, docRef: DatabaseReference, completion: #escaping ((Result<T?, Error>)->Void)) {
docRef.getDocument { (document, error) in
guard let value = snapshot.value, value as? NSNull == nil else {
completion(.success(nil))
return
}
do {
let newValue = try self.decoder.decode(T.self, from: value)
completion(.success(newValue))
} catch let error {
completion(.failure(error))
}
}
}

Answer 2

try
GetData.swift
var user = User()
let docRef = db.collection("users").document(Auth.auth().currentUser?.uid)
docRef.getDocument { (document, error) in
if let document = document, document.exists {
let dataDescription = document.data().map(String.init(describing:)) ?? "nil"
print("Document data: \(dataDescription)")
user.username = document.data(["username"]) as! String
user.email= document.data(["email"]) as! String
} else {
print("Document does not exist")
}
}