SwiftUI - Show the data fetched from Firebase in view? - swift

Question

Firebase I am trying to show data taken from Firestore in my SwiftUI view but I have a problem. I have no problem with pulling data from Firebase. But I cannot show the data as I want. I work with MVVM architecture.
My model is like this:
struct UserProfileModel: Identifiable {
#DocumentID var id : String?
var username : String
var uidFromFirebase : String
var firstName : String
var lastName : String
var email : String
}
ViewModel:
class UserProfileViewModel: ObservableObject {
#Published var user : [UserProfileModel] = []
private var db = Firestore.firestore()
func data(){
db.collection("Users").whereField("uuidFromFirebase", isEqualTo: Auth.auth().currentUser!.uid).addSnapshotListener { (snapshot, error) in
guard let documents = snapshot?.documents else {
print("No Documents")
return
}
self.user = documents.compactMap { queryDocumentSnapshot -> UserProfileModel? in
return try? queryDocumentSnapshot.data(as: UserProfileModel.self)
}
}
}
}
View:
struct MainView: View {
#ObservedObject private var viewModel = UserProfileViewModel()
var body: some View { // -> Error: The compiler is unable to type-check this expression in reasonable time; try breaking up the expression into distinct sub-expressions
VStack{
Text(viewModel.user.username) // -> I want to do this but XCode is giving an error.
// This works but I don't want to do it this way.
List(viewModel.user) { user in
VStack{
Text(user.username)
Text(user.firstName)
Text(user.lastName)
Text(user.email)
Text(user.uidFromFirebase)
}
}
}
}
}
In the videos and articles titled "SwiftUI fetch data from Firebase" that I watched and read, I have always narrated on List and ForEach. But I want to use the data wherever. I shared all my code with you. I want to learn how I can do this.

Answer 1

Looks to me like you really just want to have one user that you're pulling the data for, but you've set up your UserProfileViewModel with an array of users ([UserProfileModel]). There are a number of ways that you could take care of this. Here's one (check the code for inline comments about what is going on):
class UserProfileViewModel: ObservableObject {
#Published var user : UserProfileModel? = nil // now an optional
private var db = Firestore.firestore()
func data(){
db.collection("Users").whereField("uuidFromFirebase", isEqualTo: Auth.auth().currentUser!.uid).addSnapshotListener { (snapshot, error) in
guard let documents = snapshot?.documents else {
print("No Documents")
return
}
self.user = documents.compactMap { queryDocumentSnapshot -> UserProfileModel? in
return try? queryDocumentSnapshot.data(as: UserProfileModel.self)
}.first // Take the first document (since there probably should be only one anyway)
}
}
}
struct MainView: View {
#ObservedObject private var viewModel = UserProfileViewModel()
var body: some View {
VStack {
if let user = viewModel.user { //only display data if the user isn't nil
Text(user.username)
Text(user.firstName)
Text(user.lastName)
Text(user.email)
Text(user.uidFromFirebase)
}
}
}
}
I'd say a more traditional way of handling this might be to store your user profile document Users/uid/ -- that way you can just user document(uid) to find it rather than the whereField query.