Swift Firestore cannot get data to Object - swift

Question

Hello i try to parse a array of strings into a dao. To do so i created this:
func getUsersAbos(){
let userid = Auth.auth().currentUser?.uid
let docRef = db.collection("Users").document(userid!)
docRef.getDocument { (document, error) in
if let city = document.flatMap({
$0.data().flatMap({ (data) in
return UserBlogObject(channelAbos: data)
})
}) {
print("City: \(city)")
} else {
print("Document does not exist")
}
}
}
and here is my Dao:
import Foundation
class UserBlogObject{
var channelAbos = Any
init(channelAbos: [String]) {
self.channelAbos = channelAbos
}
init(){
}
}
i get an error at this line:
return UserBlogObject(channelAbos: data)
Cannot convert value of type '[String : Any]' to expected argument type '[String]'
please note that i want to download just an array inside the document, not the whole document.

Answer 1

You can do something like this. I don't think there is a need to overcomplicate the function with flatMap() but you can do it if you want. Here is a code example of how you could create your method.
func getUsersAbos() {
guard let userID = Auth.auth().currentUser?.uid else { return }
let docRef = db.collection("Users").document(userID)
docRef.getDocument { (document, error) in
if error != nil { return }
guard let data = document?.data() else { return }
guard let channelAbos = data["channelAbos"] as? [String] else { return }
let userBlogObject = UserBlogObject.init(channelAbos: channelAbos) // This is the created object. Handle it.
}
}
And your class:
class UserBlogObject {
var channelAbos : [String]
init(channelAbos: [String]) {
self.channelAbos = channelAbos
}
}