I'm a beginner iOS developer and I have a problem with my first application. I'm using Firebase as a backend for my app and I have already sign in and sing up methods implemented. My problem is with dismissing LoginView after Auth.auth().signIn method finishing. I've managed to do this when I'm using NavigationLink by setting ObservableObject in isActive:
NavigationLink(destination: DashboardView(), isActive: $isUserLogin) { EmptyView() }
It's working as expected: when app ending login process screen is going to next view - Dashboard.
But I don't want to use NavigationLink and creating additional step, I want just go back to Dashboard using:
self.presentationMode.wrappedValue.dismiss()
In this case I don't know how to force app to wait till method loginUser() ends. This is how my code looks now:
if loginVM.loginUser() {
appSession.isUserLogin = true
self.presentationMode.wrappedValue.dismiss()
}
I've tried to use closures but it doesn't work or I'm doing something wrong.
Many thanks!
You want to use a AuthStateDidChangeListenerHandle and #EnvrionmentObject, like so:
class SessionStore: ObservableObject {
var handle: AuthStateDidChangeListenerHandle?
#Published var isLoggedIn = false
#Published var userSession: UserModel? { didSet { self.willChange.send(self) }}
var willChange = PassthroughSubject<SessionStore, Never>()
func listenAuthenticationState() {
handle = Auth.auth().addStateDidChangeListener({ [weak self] (auth, user) in
if let user = user {
let firestoreUserID = API.FIRESTORE_DOCUMENT_USER_ID(userID: user.uid)
firestoreUserID.getDocument { (document, error) in
if let dict = document?.data() {
//Decoding the user, you can do this however you see fit
guard let decoderUser = try? UserModel.init(fromDictionary: dict) else {return}
self!.userSession = decoderUser
}
}
self!.isLoggedIn = true
} else {
self!.isLoggedIn = false
self!.userSession = nil
}
})
}
func logOut() {
do {
try Auth.auth().signOut()
print("Logged out")
} catch let error {
debugPrint(error.localizedDescription)
}
}
func unbind() {
if let handle = handle {
Auth.auth().removeStateDidChangeListener(handle)
}
}
deinit {
print("deinit - seession store")
}
}
Then simply do something along these lines:
struct InitialView: View {
#EnvironmentObject var session: SessionStore
func listen() {
session.listenAuthenticationState()
}
var body: some View {
ZStack {
Color(SYSTEM_BACKGROUND_COLOUR)
.edgesIgnoringSafeArea(.all)
Group {
if session.isLoggedIn {
DashboardView()
} else if !session.isLoggedIn {
SignInView()
}
}
}.onAppear(perform: listen)
}
}
Then in your app file, you'd have this:
InitialView()
.environmentObject(SessionStore())
By using an #EnvironmentObject you can now access the user from any view, furthermore, this also allows to track the Auth status of the user meaning if they are logged in, then the application will remember.
Related
Part of my app, I allow users to explore other users with a ForEach line - however I have quickly realised how inefficient and laggy this will become in the future.
My question is: How do I only show a few users at first (lets say 8) then once you scroll to the bottom of the displayed users more will load in?
My code is below.
SWIFT UI VIEW:
NavigationView {
VStack {
SearchBar(text: $viewModel.searchText)
.padding()
ScrollView {
LazyVStack {
ForEach(viewModel.searchableUsers) { user in
NavigationLink {
ProfileView(user: user)
} label: {
UserRowView(user: user)
}
}
}
}
}
}
VIEW MODEL:
class ExploreViewModel: ObservableObject {
#Published var users = [User]()
#Published var searchText = ""
private let config: ExploreViewModelConfiguration
var searchableUsers: [User] {
if searchText.isEmpty {
return users
} else {
let lowercasedQuery = searchText.lowercased()
return users.filter({
$0.username.contains(lowercasedQuery) ||
$0.name.lowercased().contains(lowercasedQuery)
})
}
}
let service = UserService()
init(config: ExploreViewModelConfiguration) {
self.config = config
fetchUsers(forConfig: config)
}
func fetchUsers(forConfig config: ExploreViewModelConfiguration) {
service.fetchUsers { users in
let users = users
switch config {
case .newMessage:
self.users = users.filter({ !$0.isCurrentUser })
case .search:
self.users = users
}
}
}
}
I am creating an application in which a user, based on the permissions he has, can access the various views.
I use this method to constantly check user permissions:
func checkPermission() {
let docRef = self.DatabaseFirestore.collection("Admins").document(phoneNumber)
docRef.getDocument{(document, error) in
guard error == nil else {
return
}
if let document = document, document.exists {
self.controlloAdmin = true
guard let data = document.data() else {
print("Document data was empty.")
return
}
self.permission = data["Permessi"] as? [Bool] ?? []
} else {
self.controlloAdmin = false
self.isRegistred = false
self.access = false
}
}
}
I don't know if it is the most correct function I could use, but it is one of the few that I have found that works.
This is my view:
struct AdministratorPage: View {
#StateObject var administratorManager = AdministratorManager()
// User variables.
#AppStorage("phoneNumber") var phoneNumber: String = "" // User number.
#AppStorage("Access") var access: Bool = false
var body: some View {
administratorManager.checkPermission()
return NavigationView {
HStack {
VStack {
Text("Home")
Text(phoneNumber)
// Button to log out.
Button("Logout", action: {
self.access = false
})
Button("Alert", action: {
administratorManager.message = "Error title!"
administratorManager.message = "Error message!"
administratorManager.isMessage = true
}).alert(isPresented: $administratorManager.isMessage) {
Alert(title: Text(administratorManager.title), message: Text(administratorManager.message),
dismissButton: .default(Text("Ho capito!")))
}
}
}
}
}
}
When I call the "administratorManager.checkPermission()" function and press the "Alert" button the message is displayed, but even if the button is pressed the alert does not disappear. If I don't call this function, everything works.
How can I solve? Can the alert go against firebase? Is there a more suitable method to read only one data?
photo of the screen when it got locked
I ran your code and I saw the behavior you described.
The reason is the function call directly in the body.
If you want to call a function when when you open a view, use the .onAppear function for that specific view. In your case
.onAppear {
administratorManager.checkPermission()
}
The following (worked for me with you code):
struct AdministratorPage: View {
#StateObject var administratorManager = AdministratorManager()
// User variables.
#AppStorage("phoneNumber") var phoneNumber: String = "" // User number.
#AppStorage("Access") var access: Bool = false
var body: some View {
return NavigationView {
HStack {
VStack {
Text("Home")
Text(phoneNumber)
// Button to log out.
Button("Logout", action: {
self.access = false
})
Button("Alert", action: {
administratorManager.message = "Error title!"
administratorManager.message = "Error message!"
administratorManager.isMessage = true
}).alert(isPresented: $administratorManager.isMessage) {
Alert(title: Text(administratorManager.title), message: Text(administratorManager.message),
dismissButton: .default(Text("Ho capito!")))
}
}
}
}
.onAppear {
administratorManager.checkPermission()
}
}
}
UPDATE: add Snapshot listener instead of polling
Your initial approach was doing a kind of polling, it called the function constantly. Please keep in mind, when you do a Firebase request, you will be billed for the documents you get back. If you do the polling, you get the same document multiple times and will be billed for it.
With my above mentioned example in this answer, you just call the function once.
If you now want to get the live updated from Firestore, you can add a snapshot listener. The approach would be:
func checkPermission() {
let docRef = db.collection("Admins").document(phoneNumber).addSnapshotListener() { documentSnapshot, error in //erca nella collezione se c'รจ il numero.
guard error == nil else {
print("ERROR.")
return
}
if let document = documentSnapshot {
self.controlloAdmin = true
guard let data = document.data() else {
print("Document data was empty.")
return
}
self.permission = data["Permessi"] as? [Bool] ?? []
} else {
self.controlloAdmin = false
self.isRegistred = false
self.access = false
}
}
}
Whenever a value changed on that document in Friestore, it'll be changed on your device as well.
Best, Sebastian
I am working on a SwiftUI project and using Firebase. Part of the app allows users to add business addresses to their account. In Firebase I add a BusinessAddress as a sub collection to the user.
User -> BusinessAddresses
In iOS I am using snapshotlistners and Combine to get the data from Firestore. My issue happens when one user logs out and a new user logs in. The business addresses from the first user continue to show in the view that is designated to show business addresses.
I've confirmed the Firebase code is working properly. What seems to be happening is that the creation of BusinessAddressViewModel maintains the original instance of BusinessAddressRepository from when the first user logs in.
My question is how do I "reset" the instance of businessAddressRepository in my BusinessAddressViewModel when a new user logs in?
BusinessAddressRepository
This file gets the data from Firebase. It gets the currently user that is logged in and pulls the business addresses for this user. For each log in, I can see that the proper user and addresses are being updated here.
class BusinessAddressRepository: ObservableObject {
let db = Firestore.firestore()
private var snapshotListener: ListenerRegistration?
#Published var businessAddresses = [BusinessAddress]()
init() {
startSnapshotListener()
}
func startSnapshotListener() {
guard let currentUserId = Auth.auth().currentUser else {
return
}
if snapshotListener == nil {
self.snapshotListener = db.collection(FirestoreCollection.users).document(currentUserId.uid).collection(FirestoreCollection.businessAddresses).addSnapshotListener { (querySnapshot, error) in
if let error = error {
print("Error getting documents: \(error)")
} else {
guard let documents = querySnapshot?.documents else {
print("No Business Addresses.")
return
}
self.businessAddresses = documents.compactMap { businessAddress in
do {
print("This is a business address *********** \(businessAddress.documentID)")
return try businessAddress.data(as: BusinessAddress.self)
} catch {
print(error)
}
return nil
}
}
}
}
}
}
BusinessAddressViewModel
This file uses Combine to monitor the #published property businessAddresses from bankAccountRepository. This seems to be where the problem is. For some reason, this is holding on to the instance that is created when the app starts up.
class BusinessAddressViewModel: ObservableObject {
var businessAddressRepository: BusinessAddressRepository
#Published var businessAddressRowViewModels = [BusinessAddressRowViewModel]()
private var cancellables = Set<AnyCancellable>()
init(businessAddressRepository: BusinessAddressRepository) {
self.businessAddressRepository = businessAddressRepository
self.startCombine()
}
func startCombine() {
businessAddressRepository
.$businessAddresses
.receive(on: RunLoop.main)
.map { businessAddress in
businessAddress
.map { businessAddress in
BusinessAddressRowViewModel(businessAddress: businessAddress)
}
}
.assign(to: \.businessAddressRowViewModels, on: self)
.store(in: &cancellables)
}
}
BusinessAddressViewModel is set up and an #EnvironmentObject in main.
Main
#StateObject private var businessAddressViewModel = BusinessAddressViewModel(businessAddressRepository: BusinessAddressRepository())
var body: some Scene {
WindowGroup {
ContentView()
.environmentObject(businessAddressViewModel)
}
I was able to confirm it's hanging on to the instance in the view BusinessAddressView. Here I use a List that looks at each BusinessAddress in BusinessAddressViewModel. I use print statements in the ForEach and an onAppear that show the BusinessAddresses from the first user.
BusinessAddressView
struct BusinessAddressView: View {
let db = Firestore.firestore()
#EnvironmentObject var businessAddressViewModel: BusinessAddressViewModel
var body: some View {
List {
ForEach(self.businessAddressViewModel.businessAddressRowViewModels, id: \.id) { businessAddressRowViewModel in
let _ = print("View Business Addresses \(businessAddressRowViewModel.businessAddress.id)")
NavigationLink(destination: BusinessAddressDetailView(businessAddressDetailViewModel: BusinessAddressDetailViewModel(businessAddress: businessAddressRowViewModel.businessAddress, businessAddressRepository: businessAddressViewModel.businessAddressRepository))
) {
BusinessAddressRowView(businessAddressRowViewModel: businessAddressRowViewModel)
}
} // ForEach
} // List
.onAppear(perform: {
for businessAddress in self.businessAddressViewModel.businessAddressRepository.businessAddresses {
let _ = print("On Appear Business Addresses \(businessAddress.id)")
}
}) // CurrentUserUid onAppear
} // View
}
So, how do I reset the instance of BusinessAddressViewModel and get it to look at the current BusinessAddressRepository?
I've done a ton of searching and read a bunch of articles but I cannot get SwiftUI to dynamically update the view based on changing variables in the model, at least the kind of thing I'm doing. Basically I want to update the view based on the app's UNNotificationSettings.UNAuthorizationStatus. I have the app check the status on launch and display the status. If the status is not determined, then tapping on the text will trigger the request notifications dialog. However, the view doesn't update after the user either permits or denies the notifications. I'm sure I'm missing something fundamental because I've tried it a dozen ways, including with #Published ObservableObject, #ObservedObject, #EnvironmentObject, etc.
struct ContentView: View {
#EnvironmentObject var theViewModel : TestViewModel
var body: some View {
VStack {
Text(verbatim: "Notifications are: \(theViewModel.notificationSettings.authorizationStatus)")
.padding()
}
.onTapGesture {
if theViewModel.notificationSettings.authorizationStatus == .notDetermined {
theViewModel.requestNotificationPermissions()
}
}
}
}
class TestViewModel : ObservableObject {
#Published var notificationSettings : UNNotificationSettings
init() {
notificationSettings = type(of:self).getNotificationSettings()!
}
func requestNotificationPermissions() {
let permissionsToRequest : UNAuthorizationOptions = [.alert, .sound, .carPlay, .announcement, .badge]
UNUserNotificationCenter.current().requestAuthorization(options: permissionsToRequest) { granted, error in
if granted {
print("notification request GRANTED")
}
else {
print("notification request DENIED")
}
if let error = error {
print("Error requesting notifications:\n\(error)")
}
else {
DispatchQueue.main.sync {
self.notificationSettings = type(of:self).getNotificationSettings()!
}
}
}
}
static func getNotificationSettings() -> UNNotificationSettings? {
var settings : UNNotificationSettings?
let start = Date()
let semaphore = DispatchSemaphore(value: 0)
UNUserNotificationCenter.current().getNotificationSettings { notificationSettings in
settings = notificationSettings
semaphore.signal()
}
semaphore.wait()
while settings == nil {
let elapsed = start.distance(to: Date())
Thread.sleep(forTimeInterval: TimeInterval(0.001))
if elapsed > TimeInterval(1) {
print("ERROR: did not get notification settings in less than a second, giving up!")
break
}
}
if settings != nil {
print("\(Date()) Notifications are: \(settings!.authorizationStatus)")
}
return settings
}
}
func getUNAuthorizationStatusString(_ authStatus : UNAuthorizationStatus) -> String {
switch authStatus {
case .notDetermined: return "not determined"
case .denied: return "denied"
case .authorized: return "authorized"
case .provisional: return "provisional"
case .ephemeral: return "ephemeral"
#unknown default: return "unknown case with rawValue \(authStatus.rawValue)"
}
}
extension UNAuthorizationStatus : CustomStringConvertible {
public var description: String {
return getUNAuthorizationStatusString(self)
}
}
extension String.StringInterpolation {
mutating func appendInterpolation(_ authStatus: UNAuthorizationStatus) {
appendLiteral(getUNAuthorizationStatusString(authStatus))
}
}
EDIT: I tried adding objectWillChange but the view still isn't updating.
class TestViewModel : ObservableObject {
let objectWillChange = ObservableObjectPublisher()
#Published var notificationSettings : UNNotificationSettings {
willSet {
objectWillChange.send()
}
}
init() {
notificationSettings = type(of:self).getNotificationSettings()!
}
Per the apple docs the properties wrappers like #Published should hold values. UNNotificationSettings is a reference type. Since the class gets mutated and the pointer never changes, #Publushed has no idea that you changed anything. Either publish a value (it make a struct and init it from he class) or manually send the objectwillChange message manually.
While I was not able to get it to work with manually using objectWillChange, I did create a basic working system as follows. Some functions are not repeated from the question above.
struct TestModel {
var notificationAuthorizationStatus : UNAuthorizationStatus
init() {
notificationAuthorizationStatus = getNotificationSettings()!.authorizationStatus
}
}
class TestViewModel : ObservableObject {
#Published var theModel = TestModel()
func requestAndUpdateNotificationStatus() {
requestNotificationPermissions()
theModel.notificationAuthorizationStatus = getNotificationSettings()!.authorizationStatus
}
}
struct ContentView: View {
#ObservedObject var theViewModel : TestViewModel
var body: some View {
VStack {
Button("Tap to update") {
theViewModel.requestAndUpdateNotificationStatus()
}
.padding()
switch theViewModel.theModel.notificationAuthorizationStatus {
case .notDetermined: Text("Notifications have not been requested yet.")
case .denied: Text("Notifications are denied.")
case .authorized: Text("Notifications are authorized.")
case .provisional: Text("Notifications are provisional.")
case .ephemeral: Text("Notifications are ephemeral.")
#unknown default: Text("Notifications status is an unexpected state.")
}
}
}
}
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)
}
}
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")
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