My preview crashes with the error: Failed to get FirebaseApp instance. Please call FirebaseApp.configure() before using Firestore. My guess is it is because in ProfileViewController I try to access firebase and I configure firebase in an extra class that is not called before. Is there any workaround? I tried setting var Firebasemanager = FirebaseManager() in preview but it still fails.
This is the class where I call configure():
class FirebaseManager: NSObject {
let auth: Auth
let storage: Storage
let firestore: Firestore
var currentUser: ChatUser? // User?
static let shared = FirebaseManager()
override init() {
FirebaseApp.configure()
self.auth = Auth.auth()
self.storage = Storage.storage()
self.firestore = Firestore.firestore()
super.init()
}
}
This are all the States of my View:
#Environment(\.presentationMode) var presentationMode
#State var shouldShowImagePicker: Bool = false
#State var loginStatusMessage = ""
#EnvironmentObject var viewRouter: ViewRouter
#StateObject var profileController = ProfileViewController()
#ObservedObject var userViewModel = UserViewModel()
This is what my Preview looks like:
struct ProfileView_Previews: PreviewProvider {
static var previews: some View {
ProfileView(presentationMode: Environment(\.presentationMode), shouldShowImagePicker: false, loginStatusMessage: "", profileController: ProfileViewController(), userViewModel: UserViewModel()).environmentObject(ViewRouter())
}
}
EDIT:
This is the ProfileViewController:
class ProfileViewController: ObservableObject {
let uid = FirebaseManager.shared.auth.currentUser?.uid ?? ""
let store = FirebaseManager.shared.firestore
func deleteCurrentTrack() async {
try? await store.collection("current_track").document(uid).delete()
}
}
This is where I call it in my ProfileView:
struct ProfileView: View {
var body: some View {
Button() {
Task {
await profileController.deleteCurrentTrack()
try await FirebaseManager.shared.auth.currentUser?.delete()
}
} label: {
Text("Delete track")
}
}
}
The reason my preview failed was because of UserViewModel.
At the top I set let db = Firestore.firestore(), deleting this solved the problem.
class UserViewModel: ObservableObject {
let db = Firestore.firestore()
#Published var chatUser: ChatUser?
init() {
fetchCurrentUser()
}
func fetchCurrentUser() {
guard let uid = FirebaseManager.shared.auth.currentUser?.uid else {
return
}
FirebaseManager.shared.firestore.collection("users").document(uid).getDocument { snapshot, error in
if let error = error {
print("Failed to fetch current user: ", error)
}
self.chatUser = try? snapshot?.data(as: ChatUser.self)
FirebaseManager.shared.currentUser = self.chatUser
}
}
}
My Preview looks like this:
struct ProfileView_Previews: PreviewProvider {
static var previews: some View {
ProfileView().environmentObject(ViewRouter())
}
}
Related
I am using AsyncImage to download the image and display it into view. I have created the respective properties into core data including image type is string to save the data locally . I am trying to load the into offline mode , it was able to show the rest of the properties without Image and it showing blank ..
Here is the code for Core Data manager .
class CoreDataManager {
let persistentContainer: NSPersistentContainer
static let shared: CoreDataManager = CoreDataManager()
private init() {
persistentContainer = NSPersistentContainer(name: "ReditModel")
persistentContainer.loadPersistentStores { description, error in
if let error = error {
// fatalError("Unable to initialize Core Data \(error)")
print("Unable to save the data :\(error.localizedDescription)")
}
}
}
}
Here is the code for main ..
#main
struct CoreDataDemoApp: App {
#StateObject private var viewModel = RedditViewModel()
let persistentContainer = CoreDataManager.shared.persistentContainer
var body: some Scene {
WindowGroup {
ContentView().environment(\.managedObjectContext, persistentContainer.viewContext).environmentObject(viewModel)
}
}
}
Here is the view model..
#MainActor
class RedditViewModel: ObservableObject {
#Published private(set) var stories = [Story]()
private var redditService: RedditService
init(redditService: RedditService = RedditService()) {
self.redditService = redditService
}
// Swift 5.5
func fetchData(viewContext: NSManagedObjectContext) async {
let url = NetworkURLs.urlBase
do {
let response = try await redditService.getModel(from: url)
let stories = response.data.children.map { $0.data }
self.stories = stories
saveRecord(viewContext: viewContext)
} catch (let error) {
print(error)
}
}
public func saveRecord(viewContext: NSManagedObjectContext) {
do {
stories.forEach { story in
let redit = ReditEntity(context: viewContext)
redit.title = story.title
redit.numComments = Int64(story.numComments)
redit.score = Int64(story.score)
redit.urlImage = story.thumbnail
}
try viewContext.save()
} catch {
print(error.localizedDescription)
}
}
}
Here is the code for Row view .
struct RowView: View {
#EnvironmentObject var viewModel: RedditViewModel
let title: String
let comments: String
let score: String
let urlImage: String?
var body: some View {
VStack(alignment: .leading) {
HStack {
if let urlImage = urlImage, urlImage.contains("https"), let url = URL(string: urlImage) {
AsyncImage(url: url)
}
VStack(alignment: .leading) {
HeadTitleView(title: title)
Text("Comments: \(comments)")
Text("Score: \(score)")
Spacer()
}
}
}
}
}
Here is the content view ..
struct ContentView: View {
#EnvironmentObject private var viewModel: RedditViewModel
#Environment(\.managedObjectContext) private var viewContext
#FetchRequest(entity: ReditEntity.entity(), sortDescriptors: [])
private var dbStories: FetchedResults<ReditEntity>
var dbFatchReditRecord: NSFetchRequest<ReditEntity> = ReditEntity.fetchRequest()
var body: some View {
VStack {
Text("Reddit Service")
.font(.largeTitle)
List {
ForEach(dbStories) { story in
// custom cell
RowView(title: story.title ?? "", comments: "\(story.numComments)", score: "\(story.score)", urlImage: story.urlImage)
}
}
}
.onAppear {
if dbStories.isEmpty {
Task {
await viewModel.fetchData(viewContext: viewContext)
}
}
}
}
}
struct ContentView_Previews: PreviewProvider {
static var previews: some View {
let persistedContainer = CoreDataManager.shared.persistentContainer
ContentView().environment(\.managedObjectContext, persistedContainer.viewContext) }
}
Here is the screenshot when I run the app on Offline model ..
Out of curiosity: How are you supposed to be able to load a https url while being offline?
-> urlImage.contains("https")
You should download the image and store it on your local file system. For example give your data model 2 attributes: offlineUrlString and onlineUrlString. Then as a fallback if the online url results in an empty image, then use the offline image. Once you are online again, update the offline image again.
I am trying to save and fetch data form core data by using swift UI . I debug the code , I can see the the data is saved into core data and it has 5 record but the problem is when I tried to reload and re-run it it showing only one record.
Here is the code View Model ..
import Foundation
import CoreData
#MainActor
class RedditViewModel: ObservableObject {
#Published private(set) var stories = [Story]()
private var redditService: RedditService
init(redditService: RedditService = RedditService()) {
self.redditService = redditService
}
// Swift 5.5
func fetchData(viewContext: NSManagedObjectContext) async {
let url = NetworkURLs.urlBase
do {
let response = try await redditService.getModel(from: url)
let stories = response.data.children.map { $0.data }
self.stories = stories
saveRecord(viewContext: viewContext)
} catch (let error) {
print(error)
}
}
public func saveRecord(viewContext: NSManagedObjectContext) {
do {
let redit = ReditEntity(context: viewContext)
stories.forEach { story in
redit.title = story.title
redit.numComments = Int64(story.numComments)
redit.score = Int64(story.score)
redit.urlImage = story.thumbnail
}
try viewContext.save()
} catch {
print(error.localizedDescription)
}
}
}
Here is the code for main app ..
import SwiftUI
#main
struct CoreDataDemoApp: App {
#StateObject private var viewModel = RedditViewModel()
let persistentContainer = CoreDataManager.shared.persistentContainer
var body: some Scene {
WindowGroup {
ContentView().environment(\.managedObjectContext, persistentContainer.viewContext).environmentObject(viewModel)
}
}
}
Here is code into content view ..
import SwiftUI
import CoreData
struct ContentView: View {
#EnvironmentObject private var viewModel: RedditViewModel
#Environment(\.managedObjectContext) private var viewContext
#FetchRequest(entity: ReditEntity.entity(), sortDescriptors: [])
private var dbStories: FetchedResults<ReditEntity>
var dbFatchReditRecord: NSFetchRequest<ReditEntity> = ReditEntity.fetchRequest()
var body: some View {
VStack {
Text("Reddit Service")
.font(.largeTitle)
List {
ForEach(dbStories) { story in
// custom cell
RowView(title: story.title ?? "", comments: "\(story.numComments)", score: "\(story.score)", urlImage: story.urlImage)
}
}
}
.onAppear {
if dbStories.isEmpty {
Task {
await viewModel.fetchData(viewContext: viewContext)
}
}
}
}
}
struct ContentView_Previews: PreviewProvider {
static var previews: some View {
let persistedContainer = CoreDataManager.shared.persistentContainer
ContentView().environment(\.managedObjectContext, persistedContainer.viewContext) }
}
Here is the code for RowView.swift
import SwiftUI
struct RowView: View {
#EnvironmentObject var viewModel: RedditViewModel
let title: String
let comments: String
let score: String
let urlImage: String?
var body: some View {
VStack(alignment: .leading) {
HStack {
if let urlImage = urlImage, urlImage.contains("https"), let url = URL(string: urlImage) {
AsyncImage(url: url)
}
VStack(alignment: .leading) {
HeadTitleView(title: title)
Text("Comments: \(comments)")
Text("Score: \(score)")
Spacer()
}
}
}
}
}
Here is the code for Header.swift ..
import SwiftUI
struct HeadTitleView: View {
#EnvironmentObject var viewModel: RedditViewModel
let title: String
var body: some View {
Text(title)
}
}
Here is the screenshot ..
let redit = ReditEntity(context: viewContext)
stories.forEach { story in
redit.title = story.title
...
}
Here you are creating an entity object but then you reuse that same object inside the loop so what you end up doing is updating this single object with each story instead of creating a new object for each story.
Simply swap the lines to fix the problem
stories.forEach { story in
let redit = ReditEntity(context: viewContext)
redit.title = story.title
...
}
// I am trying to pass in the value of the #AppStorage onto the class using #Binding.
// Declaration of #AppStorge, this the the single source of truth.
// I get the following error on the SigninViewModel = Class 'SigninViewModel' has no initializers
import SwiftUI
struct MainView: View {
#AppStorage("userSignIn") var userSignIn = false
var body: some View {
ZStack {
TabView {
AppointmentsView()
.tabItem {
Image(systemName: "calendar")
Text("Appointments")
}
AccountView(userSignIn: .constant(true))
.tabItem {
Image(systemName: "person")
Text("Profile")
}
StatsView()
.tabItem {
Image(systemName: "chart.bar")
Text("Stats")
}
}
}
}
}
// This the class with the #Binding is being declared and where I am trying to have access to the #AppStorae value.
class SigninViewModel: ObservableObject {
#Published var nonce = ""
#Binding var userSignIn: Bool
func authenticate(credential: ASAuthorizationAppleIDCredential) {
// getting Token...
guard let token = credential.identityToken else {
print("Error with Firebase")
return
}
//Token String...
guard let tokenString = String(data: token, encoding: .utf8) else {
print("Error with Token")
return
}
let firebaseCredential = OAuthProvider.credential(withProviderID: "apple.com",
idToken: tokenString,
rawNonce: nonce)
Auth.auth().signIn(with: firebaseCredential) { (result, err) in
if let error = err {
print(error.localizedDescription)
return
}
// User succesfully logged into Firebase...
print("Logged in Success")
// Directing user to Main page...
withAnimation(.easeInOut) {
self.userSignIn = true
}
}
}
}
You can put the #AppStorage("userSignIn") inside the ObservableObject, but your code quickly becomes a mess.
I think a more simple structure would be to put all of your authentication state inside a single AuthenticationModel: ObservableObject and use it as a #StateObject in the MainView. Additionally, I would recommend pushing it up the view tree.
class AuthenticationModel: ObservableObject {
#Published var nonce = ""
#Published var userSignIn: Bool
init() {
let defaults = UserDefaults.standard
userSignIn = defaults.bool(forKey: "userSignIn")
}
func authenticate(credential: ASAuthorizationAppleIDCredential)
...
// Successful Login
let defaults = UserDefaults.standard
defaults.set(true, forKey: "userSignIn")
// Update the views
userSignIn = true
}
}
struct MainView: View {
#StateObject var authModel: AuthenticationModel = AuthenticationModel()
var body: some View {
if authModel.userSignIn {
Home(authModel: authModel)
} else {
SignIn(authModel: authModel)
}
}
}
struct SignIn: View {
#ObservedObject var authModel: AuthenticationModel
var body: some View {
Button("Sign In") {
authModel.authenticate(...)
}
}
}
I am trying to retrieve user data once the user gets to the dashboard of my app
I have essentially this to get data:
class UserController: ObservableObject {
#Published var firstName: String = ""
func fetchUser(token: String) {
/* Do url settings */
URLSession.shared.dataTask(with: request) { (data, response, error) in
guard let data = data else { return }
let rData = try! JSONDecoder().decode(User.self, from: data)
let userData = [
"id": rData.id,
"firstName": rData.firstName,
"lastName": rData.lastName,
"department": rData.department,
]
UserDefaults.standard.set(userData, forKey: "user")
DispatchQueue.main.async {
self.firstName = rData.firstName
}
}.resume()
}
}
And then my view looks like this
struct HomeViewCollection: View {
#Binding var isAuthenticated: Bool
#ObservedObject var userController: UserController = UserController()
var body: some View {
VStack {
Text("Hello \(userController.firstName)!")
}
}
}
I'm just not sure how can I activate fetchUser from the View.
I have tried this in the controller
init() {
guard let tokenData = KeyChain.load(key: "token") else { return }
var token = String(data: tokenData, encoding: .utf8)
if(token != nil) {
print("Token: \(token)")
fetchUser(token: token!)
}
}
That didn't work, and then I tried userController.fetchUser(token: KeyChainTokenHere) and that didn't work because it doesn't conform to the struct.
Try passing the token to HomeViewCollection and initiating the call in onAppear completion block.
struct HomeViewCollection: View {
var token: String
#Binding var isAuthenticated: Bool
#ObservedObject var userController = UserController()
var body: some View {
VStack {
Text("Hello \(userController.firstName)!")
}
.onAppear {
self.userController.fetchUser(token: self.token)
}
}
}
Also, make sure the firstName property is getting set.
#Published var firstName: String = "" {
didSet {
print("firstName is set as \(firstName)")
}
}
I am creating an application using RealmSwift.
The following implementation crashed when deleting related data.
After removing only "UnderlayerItem", it succeeded.
Crash when deleting UnderlayerItem and deleting Item.
The error is:
Thread 1: Exception: "The RLMArray has been invalidated or the object
containing it has been deleted."
How do I delete without crashing?
struct ListView: View {
#ObservedObject private var fetcher = Fetcher()
#State private var title = ""
var body: some View {
NavigationView {
VStack {
TextField("add", text: $title) {
let item = Item()
item.title = self.title
let realm = try! Realm()
try! realm.write {
realm.add(item)
}
self.title = ""
}
ForEach(self.fetcher.items) { (item: Item) in
NavigationLink(destination: DetailView(item: item, id: item.id)) {
Text(item.title)
}
}
}
}
}
}
struct DetailView: View {
var item: Item
var id: String
#State private var title = ""
#ObservedObject private var fetcher = Fetcher()
#Environment(\.presentationMode) private var presentationMode: Binding<PresentationMode>
var body: some View {
VStack {
TextField("add", text: $title) {
let realm = try! Realm()
if let item = realm.objects(Item.self).filter("id == '\(self.id)'").first {
try! realm.write() {
let underlayerItem = UnderlayerItem()
underlayerItem.title = self.title
item.underlayerItems.append(underlayerItem)
}
}
self.title = ""
}
ForEach(self.item.underlayerItems) { (underlayerItems: UnderlayerItem) in
Text(underlayerItems.title)
}
Button(action: {
self.presentationMode.wrappedValue.dismiss()
self.fetcher.delete(id: self.id)
}) {
Text("Delete")
}
}
}
}
class Fetcher: ObservableObject {
var realm = try! Realm()
var objectWillChange: ObservableObjectPublisher = .init()
private(set) var items: Results<Item>
private var notificationTokens: [NotificationToken] = []
init() {
items = realm.objects(Item.self)
notificationTokens.append(items.observe { _ in
self.objectWillChange.send()
})
}
func delete(id: String) {
guard let item = realm.objects(Item.self).filter("id == '\(id)'").first else { return }
try! realm.write() {
for underlayerItem in item.underlayerItems {
realm.delete(realm.objects(UnderlayerItem.self).filter("id == '\(underlayerItem.id)'").first!)
}
}
try! realm.write() {
realm.delete(item)
}
}
}
class Item: Object, Identifiable {
#objc dynamic var id = NSUUID().uuidString
#objc dynamic var title = ""
#objc dynamic var createdAt = NSDate()
let underlayerItems: List<UnderlayerItem> = List<UnderlayerItem>()
override static func primaryKey() -> String? {
return "id"
}
}
class UnderlayerItem: Object, Identifiable {
#objc dynamic var id = NSUUID().uuidString
#objc dynamic var title = ""
#objc dynamic var createdAt = NSDate()
override static func primaryKey() -> String? {
return "id"
}
}
You don't need to iterate over the objects in the list to delete them. Just do this
try! realm.write() {
realm.delete(item.underlayerItems)
}
I believe it's crashing because you're attempting to access an item that was deleted
self.item.underlayerItems