Display query values within view's body - google-cloud-firestore

Question

What I want to do: I want to display the user's name on the Profile view after a user logs into the app. Currently I have implemented a login using Firebase Auth. When users create an account, it creates a record in the "Users" collection in Firestore that records First and Last Name and email address.
What I've Tried: On the Profile view, I currently have a function "getUser" that checks if the user is logged in, and then matches the user's Firebase Auth email address and matches it to the record in Firestore. This is working because I've checked what info the query is returning by what's logged in the console. However, I'm at a lost how to get the "fName" information and displaying it within the view's body.
Here's screenshots of the database structure and my current code.
import SwiftUI
import Firebase
import Combine
import FirebaseFirestore
struct ProfileView: View {
#EnvironmentObject var session: SessionStore
let db = Firestore.firestore()
func getUser() {
session.listen()
let query = db.collection("users").whereField("email", isEqualTo: session.session!.email!)
query.getDocuments { (QuerySnapshot, err) in
if let docs = QuerySnapshot?.documents {
for docSnapshot in docs {
print (docSnapshot.data())
}
}
}
}
var body: some View {
Group {
if (session.session != nil) {
NavigationView {
VStack {
Text("Welcome back \(session.session!.email ?? "user")")
Spacer()
Button(action: session.signOut) {
Text("Sign Out")
}.padding(.bottom, 60)
}
} // end NavigationView
} else {
AuthView()
}
}.onAppear(perform: getUser)
}
}

Answer 1

I guess you should save the values returned from Firestore with UserDefaults
import UIKit
//your get user data logic here
let fName:String = <the first name retrieved from firestore>
// Get the standard UserDefaults as "defaults"
let defaults = UserDefaults.standard
// Save the String to the standard UserDefaults under the key, "first_name"
defaults.set(fName, forKey: "first_name")
And in your profile page you should retrieve this value
// you should have defaults initialized here
fnameToDisplay = defaults.string(forKey: "first_name")

Answer 2

Hello I prefer to make a ViewModel - NetworkManager class that comfort ObservableObject and inside of it you can get and fetch data and when they finish loading they will update the view, Let me show you an example how it works:
as you can see I created a NetworkManager extends ObservableObject (cause I want to get notified when the user finish loading) inside of it you can see that var user is annotated with #Published that make the user observed and when a new data set will notify the View to update. also you can see that I load the data on init so the fist time this class initialized it will call the fetchData() func
class NetworkManager: ObservableObject {
let url: String = "https://jsonplaceholder.typicode.com/todos/1"
var objectWillChange = PassthroughSubject<NetworkManager, Never>()
init() {
fetchData()
}
#Published var user: User? {
didSet {
objectWillChange.send(self)
print("set user")
}
}
func fetchData() {
guard let url = URL(string: url) else {return}
print("fetch data")
URLSession.shared.dataTask(with: url) { (data, response, error) in
guard error == nil else {return}
print("no error")
guard let data = data else {return}
print("data is valid")
let user = try! JSONDecoder().decode(User.self, from: data)
DispatchQueue.main.async {
self.user = user
}
}.resume()
}
}
ContentView is where I'm gonna place the user data or info I declared #ObservedObject var networkManager cause it extend ObservableObject and I place the views and pass User
struct ContentView: View {
#ObservedObject var networkManager = NetworkManager()
var body: some View {
VStack {
DetailsView(user: networkManager.user)
}
}
}
struct DetailsView: View {
var user: User?
var body: some View {
VStack {
Text("id: \(user?.id ?? 0)")
Text("UserID: \(user?.userId ?? 0 )")
Text("title: \(user?.title ?? "Empty")")
}
}
}
class User: Decodable, ObservableObject {
var userId: Int = 0
var id: Int = 0
var title: String = ""
var completed: Bool = false
}
PS: I didn't make objects unwrapped correctly please consider that so
you not to have any nil exception