Firebase for Apple Developers

Transcript

1. Peter Friese | Developer Advocate, Firebase Charlo!e Liang | So"ware

   Engineer, Firebase  + Firebase for Apple Developers @charlo!eCLiang @pete#riese

2. Architecture Swi!UI 2 Life Cycle Firebase Firestore Authentication Combine async/await

   Completion block WidgetKit

3. Architecture For Data-Driven Apps Photo by Lance Anderson on Unsplash

4. #one-book-a-week-challenge

5. None

6. Drill-down navigation Three-column layout (iPad / Mac) Single source of

   truth Driving factors UI always in sync

7. UI always in sync

8. BookShelfView BookEditView BookDetailsView BookRowView Source of Truth books: [Book] @ObservableObject

   @Binding Book Book Book

9. Challenge #1 This needs to be a binding But this

   isn’t a list of bindings

10. struct BookShelfView: View { @Binding var bookShelf: BookShelf var body:

    some View { List { ForEach(Array(bookShelf.books.enumerated()), id: \.element.id) { index, item in BookRowView(book: $bookShelf.books[index]) } .onDelete { indexSet in bookShelf.books.remove(atOffsets: indexSet) } } .navigationTitle(bookShelf.title) } } Solution #1: iterate over enumerated items !

11. struct BookShelfView: View { @Binding var bookShelf: BookShelf var body:

    some View { List { ForEach($bookShelf.books) { $book in BookRowView(book: $book) } .onDelete { indexSet in bookShelf.books.remove(atOffsets: indexSet) } } .navigationTitle(bookShelf.title) } } Solution #1: use list bindings Everything is now bindable

12. Learn more h"ps://pete#riese.dev/swi!ui-list-item-bindings-behind-the-scenes/

13. How to update only when the user commits? Challenge #2

14. struct BookEditView: View { @Binding var book: Book @ObservedObject var

    bookEditViewModel: BookEditViewModel init(book: Binding<Book>) { self._book = book self.bookEditViewModel = BookEditViewModel(book: book.wrappedValue) } var body: some View { TextField("Book title", text: $bookEditViewModel.book.title) } func save() { self.book = bookEditViewModel.book dismiss() } } Solution 2: use inner @ObservableObject

15. struct BookEditView: View { @Binding var book: Book @ObservedObject var

    bookEditViewModel: BookEditViewModel init(book: Binding<Book>) { self._book = book self.bookEditViewModel = BookEditViewModel(book: book.wrappedValue) } var body: some View { TextField("Book title", text: $bookEditViewModel.book.title) } func save() { self.book = bookEditViewModel.book dismiss() } } Solution 2: use inner @ObservableObject

16. struct BookEditView: View { @Binding var book: Book @ObservedObject var

    bookEditViewModel: BookEditViewModel init(book: Binding<Book>) { self._book = book self.bookEditViewModel = BookEditViewModel(book: book.wrappedValue) } var body: some View { TextField("Book title", text: $bookEditViewModel.book.title) } func save() { self.book = bookEditViewModel.book dismiss() } } Solution 2: use inner @ObservableObject

17. struct BookEditView: View { @Binding var book: Book @ObservedObject var

    bookEditViewModel: BookEditViewModel init(book: Binding<Book>) { self._book = book self.bookEditViewModel = BookEditViewModel(book: book.wrappedValue) } var body: some View { TextField("Book title", text: $bookEditViewModel.book.title) } func save() { self.book = bookEditViewModel.book dismiss() } } Solution 2: use inner @ObservableObject

18. Solution 2

19. class BookEditViewModel: ObservableObject { @Published var book: Book @Published var

    isISBNValid: Bool = true init(book: Book) { self.book = book self.$book .map { checkISBN(isbn: $0.isbn) } .assign(to: &$isISBNValid) } } Solution 2: use inner @ObservableObject Bonus: use Combine to perform validation

20. Learn more about Building SwiftUI Components h"ps://www.youtube.com/c/pete#riese

21. Architecture Swi!UI 2 Life Cycle Firebase Firestore Authentication Combine async/await

    Completion block WidgetKit
22. None

23. Run with confidence Engage users Develop apps faster

24. Run with confidence Crashlytics Performance Monitoring Test Lab App Distribution

    Engage users Analytics Predictions Cloud Messaging Remote Config A/B Testing Dynamic Links In-app Messaging Develop apps faster Auth Cloud Functions Cloud Firestore Hosting ML Kit Realtime Database Cloud Storage bit.ly/what-is-firebase Extensions Machine Learning
25. None
26. None
27. None

28. #protip: Put it beneath Asset.xcasset

29. Don’t forget to add to all the targets!

30. Swift Package Manager now officially supported! h"ps://github.com/%rebase/%rebase-ios-sdk

31. !

32. Application Lifecycle SwiftUI 2 Photo by Thor Alvis on Unsplash

33. SwiftUI 2: No more AppDelegate! import SwiftUI @main struct BookShelfApp:

    App { @StateObject var store = BookShelfStore(shelves: BookShelf.samples) var body: some Scene { WindowGroup { NavigationView { BookShelvesView(store: store) Text("Select a shelf to see its books") Text("Select a book to see its details") } } } }

34. SwiftUI 2: No more AppDelegate! import SwiftUI @main struct BookShelfApp:

    App { @StateObject var store = BookShelfStore(shelves: BookShelf.samples) var body: some Scene { WindowGroup { NavigationView { BookShelvesView(store: store) Text("Select a shelf to see its books") Text("Select a book to see its details") } } } }

35. Solution 1: use initialiser import SwiftUI @main struct BookShelfApp: App

    { @StateObject var store = BookShelfStore(shelves: BookShelf.samples) var body: some Scene { WindowGroup { NavigationView { BookShelvesView(store: store) Text("Select a shelf to see its books") Text("Select a book to see its details") }

36. Solution 1: use initialiser import SwiftUI @main struct BookShelfApp: App

    { @StateObject var store = BookShelfStore(shelves: BookShelf.samples) var body: some Scene { WindowGroup { NavigationView { BookShelvesView(store: store) Text("Select a shelf to see its books") Text("Select a book to see its details") } init() { FirebaseApp.configure() }

37. Solution 2: use UIApplicationDelegateAdaptor import SwiftUI import Firebase class AppDelegate:

    NSObject, UIApplicationDelegate { func application(_ application: UIApplication, didFinishLaunchingWithOptions launchOptions: [UIApplication.LaunchOptionsKey : Any]? = nil) !" Bool { FirebaseApp.configure() return true } } @main struct BookShelfApp: App { @UIApplicationDelegateAdaptor(AppDelegate.self) var delegate

38. Solution 2: use UIApplicationDelegateAdaptor import SwiftUI import Firebase class AppDelegate:

    NSObject, UIApplicationDelegate { func application(_ application: UIApplication, didFinishLaunchingWithOptions launchOptions: [UIApplication.LaunchOptionsKey : Any]? = nil) !" Bool { FirebaseApp.configure() return true } } @main struct BookShelfApp: App { @UIApplicationDelegateAdaptor(AppDelegate.self) var delegate

39. Solution 2: use UIApplicationDelegateAdaptor import SwiftUI import Firebase class AppDelegate:

    NSObject, UIApplicationDelegate { func application(_ application: UIApplication, didFinishLaunchingWithOptions launchOptions: [UIApplication.LaunchOptionsKey : Any]? = nil) !" Bool { FirebaseApp.configure() return true } } @main struct BookShelfApp: App { @UIApplicationDelegateAdaptor(AppDelegate.self) var delegate

40. Solution 2: use UIApplicationDelegateAdaptor import SwiftUI import Firebase class AppDelegate:

    NSObject, UIApplicationDelegate { func application(_ application: UIApplication, didFinishLaunchingWithOptions launchOptions: [UIApplication.LaunchOptionsKey : Any]? = nil) !" Bool { FirebaseApp.configure() return true } } @main struct BookShelfApp: App { @UIApplicationDelegateAdaptor(AppDelegate.self) var delegate

41. Watch the scene phase Handle deep links Continue user activities

    Do more with the new life cycle

42. Watch the scene phase Handle deep links Continue user activities

    Learn more pete#riese.dev/ultimate-guide-to-swi!ui2-application-lifecycle/

43. Architecture Swi!UI 2 Life Cycle Firebase Firestore Authentication Combine async/await

    Completion block WidgetKit

44. Firestore

45. None
46. None

47. One-Time Fetches Offline Mode Effortless Syncing

48. bird_type: airspeed: coconut_capacity: isNative: icon: vector: distances_traveled: "swallow" 42.733 0.62

    false <binary data> { x: 36.4255, y: 25.1442, z: 18.8816 } [42, 39, 12, 42] Document

49. Collection Sub-Collection

50. Top level collections “books” collection a single book document

51. struct Book: Identifiable { var id = String? var shelfId:

    String? var userId: String? var title: String var author: String var isbn: String var pages: Int var isRead: Bool = false var coverEditionKey: String? } Data Model

52. func fetchBook(documentId: String) { let docRef = Firestore.firestore().collection("books").document(documentId) docRef.getDocument {

    document, error in if let error = error as NSError? { print("Error getting document: \(error.localizedDescription)") } else { if let document = document { let id = document.documentID let data = document.data() let title = data?["title"] as? String !# "" let numberOfPages = data?["numberOfPages"] as? Int !# 0 let author = data?["author"] as? String !# "" self.book = Book(id:id, title: title, numberOfPages: numberOfPages, author: author) } } } } Fetching a document from Firestore

53. func fetchBook(documentId: String) { let docRef = Firestore.firestore().collection("books").document(documentId) docRef.getDocument {

    document, error in if let error = error as NSError? { print("Error getting document: \(error.localizedDescription)") } else { if let document = document { let id = document.documentID let data = document.data() let title = data?["title"] as? String !# "" let numberOfPages = data?["numberOfPages"] as? Int !# 0 let author = data?["author"] as? String !# "" self.book = Book(id:id, title: title, numberOfPages: numberOfPages, author: author) } } } } Fetching a document from Firestore

54. func fetchBook(documentId: String) { let docRef = Firestore.firestore().collection("books").document(documentId) docRef.getDocument {

    document, error in if let error = error as NSError? { print("Error getting document: \(error.localizedDescription)") } else { if let document = document { let id = document.documentID let data = document.data() let title = data?["title"] as? String !# "" let numberOfPages = data?["numberOfPages"] as? Int !# 0 let author = data?["author"] as? String !# "" self.book = Book(id:id, title: title, numberOfPages: numberOfPages, author: author) } } } } Fetching a document from Firestore

55. func fetchBook(documentId: String) { let docRef = Firestore.firestore().collection("books").document(documentId) docRef.getDocument {

    document, error in if let error = error as NSError? { print("Error getting document: \(error.localizedDescription)") } else { if let document = document { let id = document.documentID let data = document.data() let title = data?["title"] as? String !# "" let numberOfPages = data?["numberOfPages"] as? Int !# 0 let author = data?["author"] as? String !# "" self.book = Book(id:id, title: title, numberOfPages: numberOfPages, author: author) } } } } Fetching a document from Firestore

56. func fetchBook(documentId: String) { let docRef = Firestore.firestore().collection("books").document(documentId) docRef.getDocument {

    document, error in if let error = error as NSError? { print("Error getting document: \(error.localizedDescription)") } else { if let document = document { let id = document.documentID let data = document.data() let title = data?["title"] as? String !# "" let numberOfPages = data?["numberOfPages"] as? Int !# 0 let author = data?["author"] as? String !# "" self.book = Book(id:id, title: title, numberOfPages: numberOfPages, author: author) } } } } Fetching a document from Firestore

57. func fetchBook(documentId: String) { let docRef = Firestore.firestore().collection("books").document(documentId) docRef.getDocument {

    document, error in if let error = error as NSError? { print("Error getting document: \(error.localizedDescription)") } else { if let document = document { let id = document.documentID let data = document.data() let title = data?["title"] as? String !# "" let numberOfPages = data?["numberOfPages"] as? Int !# 0 let author = data?["author"] as? String !# "" self.book = Book(id:id, title: title, numberOfPages: numberOfPages, author: author) } } } } Fetching a document from Firestore

58. func fetchBook(documentId: String) { let docRef = Firestore.firestore().collection("books").document(documentId) docRef.getDocument {

    document, error in if let error = error as NSError? { print("Error getting document: \(error.localizedDescription)") } else { if let document = document { let id = document.documentID let data = document.data() let title = data?["title"] as? String !# "" let numberOfPages = data?["numberOfPages"] as? Int !# 0 let author = data?["author"] as? String !# "" self.book = Book(id:id, title: title, numberOfPages: numberOfPages, author: author) } } } } Fetching a document from Firestore if let document = document { let id = document.documentID let data = document.data() let title = data?["title"] as? String !# "" let numberOfPages = data?["numberOfPages"] as? Int !# 0 let author = data?["author"] as? String !# "" self.book = Book(id:id, title: title, numberOfPages: numberOfPages, author: author) } Can we do better?

59. (Yes, we can)

60. func fetchBook(documentId: String) { let docRef = Firestore.firestore().collection("books").document(documentId) docRef.getDocument {

    document, error in if let error = error as NSError? { print("Error getting document: \(error.localizedDescription)") } else { if let document = document { let id = document.documentID let data = document.data() let title = data?["title"] as? String !# "" let numberOfPages = data?["numberOfPages"] as? Int !# 0 let author = data?["author"] as? String !# "" self.book = Book(id:id, title: title, numberOfPages: numberOfPages, author: author) } } } } Fetching a document from Firestore

61. func fetchBook(documentId: String) { let docRef = Firestore.firestore().collection("books").document(documentId) docRef.getDocument {

    document, error in if let error = error as NSError? { print("Error getting document: \(error.localizedDescription)") } else { } } } Mapping data using Codable if let document = document { do { self.book = try document.data(as: Book.self) } catch { print(error) } }

62. func fetchBook(documentId: String) { let docRef = Firestore.firestore().collection("books").document(documentId) docRef.getDocument {

    document, error in if let error = error as NSError? { print("Error getting document: \(error.localizedDescription)") } else { } } } Mapping data using Codable if let document = document { do { self.book = try document.data(as: Book.self) } catch { print(error) } }

63. BookShelfView BookEditView BookDetailsView BookRowView Source of Truth books: [Book] @ObservableObject

    @Binding Book Book Book Review: Architecture

64. BookShelfView BookDetailsView BookRowView Source of Truth books: [Book] @ObservableObject @Binding

    Book Book Review: Architecture Snapshot Listener

65. class BookStore: ObservableObject { var db = Firestore.firestore() private var

    listenerRegistration: ListenerRegistration? @Published var books = [Book]() func subscribe() { listenerRegistration = db.collection("books") .addSnapshotListener { [weak self] (querySnapshot, error) in guard let documents = querySnapshot!$documents else { return } self!$books = documents.compactMap { queryDocumentSnapshot in let result = Result { try queryDocumentSnapshot.data(as: Book.self) } switch result { case .success(let book): if let book = book { return book Fetching a collection of documents

66. class BookStore: ObservableObject { var db = Firestore.firestore() private var

    listenerRegistration: ListenerRegistration? @Published var books = [Book]() func subscribe() { listenerRegistration = db.collection("books") .addSnapshotListener { [weak self] (querySnapshot, error) in guard let documents = querySnapshot!$documents else { return } self!$books = documents.compactMap { queryDocumentSnapshot in let result = Result { try queryDocumentSnapshot.data(as: Book.self) } switch result { case .success(let book): if let book = book { return book Fetching a collection of documents

67. class BookStore: ObservableObject { var db = Firestore.firestore() private var

    listenerRegistration: ListenerRegistration? @Published var books = [Book]() func subscribe() { listenerRegistration = db.collection("books") .addSnapshotListener { [weak self] (querySnapshot, error) in guard let documents = querySnapshot!$documents else { return } self!$books = documents.compactMap { queryDocumentSnapshot in let result = Result { try queryDocumentSnapshot.data(as: Book.self) } switch result { case .success(let book): if let book = book { return book Fetching a collection of documents

68. class BookStore: ObservableObject { var db = Firestore.firestore() private var

    listenerRegistration: ListenerRegistration? @Published var books = [Book]() func subscribe() { listenerRegistration = db.collection("books") .addSnapshotListener { [weak self] (querySnapshot, error) in guard let documents = querySnapshot!$documents else { return } self!$books = documents.compactMap { queryDocumentSnapshot in let result = Result { try queryDocumentSnapshot.data(as: Book.self) } switch result { case .success(let book): if let book = book { return book Fetching a collection of documents

69. class BookStore: ObservableObject { var db = Firestore.firestore() private var

    listenerRegistration: ListenerRegistration? @Published var books = [Book]() func subscribe() { listenerRegistration = db.collection("books") .addSnapshotListener { [weak self] (querySnapshot, error) in guard let documents = querySnapshot!$documents else { return } self!$books = documents.compactMap { queryDocumentSnapshot in let result = Result { try queryDocumentSnapshot.data(as: Book.self) } switch result { case .success(let book): if let book = book { return book Fetching a collection of documents

70. class BookStore: ObservableObject { var db = Firestore.firestore() private var

    listenerRegistration: ListenerRegistration? @Published var books = [Book]() func subscribe() { listenerRegistration = db.collection("books") .addSnapshotListener { [weak self] (querySnapshot, error) in guard let documents = querySnapshot!$documents else { return } self!$books = documents.compactMap { queryDocumentSnapshot in let result = Result { try queryDocumentSnapshot.data(as: Book.self) } switch result { case .success(let book): if let book = book { return book Fetching a collection of documents

71. class BookStore: ObservableObject { var db = Firestore.firestore() private var

    listenerRegistration: ListenerRegistration? @Published var books = [Book]() func subscribe() { listenerRegistration = db.collection("books") .addSnapshotListener { [weak self] (querySnapshot, error) in guard let documents = querySnapshot!$documents else { return } self!$books = documents.compactMap { queryDocumentSnapshot in let result = Result { try queryDocumentSnapshot.data(as: Book.self) } switch result { case .success(let book): if let book = book { return book Fetching a collection of documents
72. None

73. Learn more h"ps://pete#riese.dev/%restore-codable-the-comprehensive-guide/

74. import Foundation import Combine import Firebase import FirebaseFirestoreSwift import os

    class BookStore: ObservableObject { !% MARK: - Dependencies var db = Firestore.firestore() !% MARK: - Publishers @Published var user: User? @Published var books = [Book]() !% MARK: - Private attributes @Published private var userId: String = "unknown" private var listenerRegistration: ListenerRegistration? private var cancellables = Set<AnyCancellable>() Fetching a collection of documents

75. !% A Book value could not be initialized from the

    DocumentSnapshot. switch error { case DecodingError.typeMismatch(_, let context): self!$logger.debug("\(error.localizedDescription): \ (context.debugDescription)") case DecodingError.valueNotFound(_, let context): self!$logger.debug("\(error.localizedDescription): \ (context.debugDescription)") case DecodingError.keyNotFound(_, let context): self!$logger.debug("\(error.localizedDescription): \ (context.debugDescription)") case DecodingError.dataCorrupted(let key): self!$logger.debug("\(error.localizedDescription): \ (key.debugDescription)") default: self!$logger.debug("Error decoding document: \ (error.localizedDescription)") } return nil } } } } Fetching a collection of documents

76. !% A Book value could not be initialized from the

    DocumentSnapshot. switch error { case DecodingError.typeMismatch(_, let context): self!$logger.debug("\(error.localizedDescription): \ (context.debugDescription)") case DecodingError.valueNotFound(_, let context): self!$logger.debug("\(error.localizedDescription): \ (context.debugDescription)") case DecodingError.keyNotFound(_, let context): self!$logger.debug("\(error.localizedDescription): \ (context.debugDescription)") case DecodingError.dataCorrupted(let key): self!$logger.debug("\(error.localizedDescription): \ (key.debugDescription)") default: self!$logger.debug("Error decoding document: \ (error.localizedDescription)") } return nil } } } } Fetching a collection of documents about 100 lines of code

77. struct BookShelfView: View { @FirestoreQuery( collectionPath: "books", predicates: [ .where("userId",

    isEqualTo: userId), ] ) var books: Result<[Book], Error> @State var userId = "F18EBA5E" var body: some View { List(books) { book in Text(book.title) } } } Firestore Property Wrapper Firebase 8.9.0 @FloWritesCode @mo&enditlevsen Thanks to

78. Architecture Swi!UI 2 Life Cycle Firebase Firestore Authentication Combine async/await

    Completion block WidgetKit

79. Driving User Engagement Photo by ROBIN WORRALL on Unsplash

80. Driving User Engagement Noti%cations Share Extensions WidgetKit

81. Notification Service Extension Noti%cation Service Extension + Firebase Messaging Be!er

    visualisation of noti%cations Available in watchOS as well

82. Watch the scene phase Handle deep links Continue user activities

    Learn more h"ps://%rebase.blog/posts/2019/09/fcm-image-noti%cation

83. Firebase + WidgetKit Mini travel blog How to initialise Firebase

    How to access Firebase services

84. Post Image ShareExtension Widget iOS App Architecture

85. class ShareViewController: SLComposeServiceViewController { override func didSelectPost() { !" get

    data from share controller context Task { !" write image data to Cloud Storage let _ = try await ref.putDataAsync(self.imageData as Data) let url = try await ref.downloadURL() !" write post data to Firestore let post = Post(description: description !# "", url: url.absoluteString) try db.collection("Posts").document("post").setData(from: post) !" refresh widgets and return to share controller WidgetCenter.shared.reloadAllTimelines() extensionContext!$completeRequest(returningItems: []) } } Firebase in a ShareViewController

86. class ShareViewController: SLComposeServiceViewController { override func didSelectPost() { !" get

    data from share controller context Task { !" write image data to Cloud Storage let _ = try await ref.putDataAsync(self.imageData as Data) let url = try await ref.downloadURL() !" write post data to Firestore let post = Post(description: description !# "", url: url.absoluteString) try db.collection("Posts").document("post").setData(from: post) !" refresh widgets and return to share controller WidgetCenter.shared.reloadAllTimelines() extensionContext!$completeRequest(returningItems: []) } } Firebase in a ShareViewController

87. class ShareViewController: SLComposeServiceViewController { override func didSelectPost() { !" get

    data from share controller context Task { !" write image data to Cloud Storage let _ = try await ref.putDataAsync(self.imageData as Data) let url = try await ref.downloadURL() !" write post data to Firestore let post = Post(description: description !# "", url: url.absoluteString) try db.collection("Posts").document("post").setData(from: post) !" refresh widgets and return to share controller WidgetCenter.shared.reloadAllTimelines() extensionContext!$completeRequest(returningItems: []) } } Firebase in a ShareViewController

88. class ShareViewController: SLComposeServiceViewController { override func didSelectPost() { !" get

    data from share controller context Task { !" write image data to Cloud Storage let _ = try await ref.putDataAsync(self.imageData as Data) let url = try await ref.downloadURL() !" write post data to Firestore let post = Post(description: description !# "", url: url.absoluteString) try db.collection("Posts").document("post").setData(from: post) !" refresh widgets and return to share controller WidgetCenter.shared.reloadAllTimelines() extensionContext!$completeRequest(returningItems: []) } } Firebase in a ShareViewController

89. class ShareViewController: SLComposeServiceViewController { override func didSelectPost() { !" get

    data from share controller context Task { !" write image data to Cloud Storage let _ = try await ref.putDataAsync(self.imageData as Data) let url = try await ref.downloadURL() !" write post data to Firestore let post = Post(description: description !# "", url: url.absoluteString) try db.collection("Posts").document("post").setData(from: post) !" refresh widgets and return to share controller WidgetCenter.shared.reloadAllTimelines() extensionContext!$completeRequest(returningItems: []) } } Firebase in a ShareViewController

90. class ShareViewController: SLComposeServiceViewController { override func didSelectPost() { !" get

    data from share controller context Task { !" write image data to Cloud Storage let _ = try await ref.putDataAsync(self.imageData as Data) let url = try await ref.downloadURL() !" write post data to Firestore let post = Post(description: description !# "", url: url.absoluteString) try db.collection("Posts").document("post").setData(from: post) !" refresh widgets and return to share controller WidgetCenter.shared.reloadAllTimelines() extensionContext!$completeRequest(returningItems: []) } } Firebase in a ShareViewController

91. Post Image ShareExtension Widget iOS App Architecture Post Image

92. func getTimeline(for configuration: ConfigurationIntent, in context: Context, completion: @escaping (Timeline<Entry>)

    !" Void) { if FirebaseApp.app() !& nil { FirebaseApp.configure() } Task { let (image, text) = try await PostRepository.getPost(imageName: “image.png") let entry = SimpleEntry( date: Calendar.current.date(byAdding: .minute, value: 15, to: Date())!, configuration: configuration, image: image, text: text ) let timeline = Timeline(entries: [entry], policy: .atEnd) completion(timeline) } } Firebase in a Widget

93. func getTimeline(for configuration: ConfigurationIntent, in context: Context, completion: @escaping (Timeline<Entry>)

    !" Void) { if FirebaseApp.app() !& nil { FirebaseApp.configure() } Task { let (image, text) = try await PostRepository.getPost(imageName: “image.png") let entry = SimpleEntry( date: Calendar.current.date(byAdding: .minute, value: 15, to: Date())!, configuration: configuration, image: image, text: text ) let timeline = Timeline(entries: [entry], policy: .atEnd) completion(timeline) } } Firebase in a Widget

94. func getTimeline(for configuration: ConfigurationIntent, in context: Context, completion: @escaping (Timeline<Entry>)

    !" Void) { if FirebaseApp.app() !& nil { FirebaseApp.configure() } Task { let (image, text) = try await PostRepository.getPost(imageName: “image.png") let entry = SimpleEntry( date: Calendar.current.date(byAdding: .minute, value: 15, to: Date())!, configuration: configuration, image: image, text: text ) let timeline = Timeline(entries: [entry], policy: .atEnd) completion(timeline) } } Firebase in a Widget

95. func getTimeline(for configuration: ConfigurationIntent, in context: Context, completion: @escaping (Timeline<Entry>)

    !" Void) { if FirebaseApp.app() !& nil { FirebaseApp.configure() } Task { let (image, text) = try await PostRepository.getPost(imageName: “image.png") let entry = SimpleEntry( date: Calendar.current.date(byAdding: .minute, value: 15, to: Date())!, configuration: configuration, image: image, text: text ) let timeline = Timeline(entries: [entry], policy: .atEnd) completion(timeline) } } Firebase in a Widget

96. func getTimeline(for configuration: ConfigurationIntent, in context: Context, completion: @escaping (Timeline<Entry>)

    !" Void) { if FirebaseApp.app() !& nil { FirebaseApp.configure() } Task { let (image, text) = try await PostRepository.getPost(imageName: “image.png") let entry = SimpleEntry( date: Calendar.current.date(byAdding: .minute, value: 15, to: Date())!, configuration: configuration, image: image, text: text ) let timeline = Timeline(entries: [entry], policy: .atEnd) completion(timeline) } } Firebase in a Widget

97. import FirebaseStorage import FirebaseStorageSwift import FirebaseFirestore import FirebaseFirestoreSwift struct PostRepository

    { static func getPost(imageName: String) async throws !" (UIImage, String) { let ref = Storage.storage().reference().child(imageName) let data = try await ref.data(maxSize: 20 * 1024 * 2048) let image = UIImage(data: data)! let db = Firestore.firestore() let docRef = db.collection("Posts").document("post") let document = try await docRef.getDocument() let post = try document.data(as: Post.self) return (image, post.description) Firebase in a Widget

98. import FirebaseStorage import FirebaseStorageSwift import FirebaseFirestore import FirebaseFirestoreSwift struct PostRepository

    { static func getPost(imageName: String) async throws !" (UIImage, String) { let ref = Storage.storage().reference().child(imageName) let data = try await ref.data(maxSize: 20 * 1024 * 2048) let image = UIImage(data: data)! let db = Firestore.firestore() let docRef = db.collection("Posts").document("post") let document = try await docRef.getDocument() let post = try document.data(as: Post.self) return (image, post.description) Firebase in a Widget

99. import FirebaseStorage import FirebaseStorageSwift import FirebaseFirestore import FirebaseFirestoreSwift struct PostRepository

    { static func getPost(imageName: String) async throws !" (UIImage, String) { let ref = Storage.storage().reference().child(imageName) let data = try await ref.data(maxSize: 20 * 1024 * 2048) let image = UIImage(data: data)! let db = Firestore.firestore() let docRef = db.collection("Posts").document("post") let document = try await docRef.getDocument() let post = try document.data(as: Post.self) return (image, post.description) Firebase in a Widget

100. import FirebaseStorage import FirebaseStorageSwift import FirebaseFirestore import FirebaseFirestoreSwift struct PostRepository

     { static func getPost(imageName: String) async throws !" (UIImage, String) { let ref = Storage.storage().reference().child(imageName) let data = try await ref.data(maxSize: 20 * 1024 * 2048) let image = UIImage(data: data)! let db = Firestore.firestore() let docRef = db.collection("Posts").document("post") let document = try await docRef.getDocument() let post = try document.data(as: Post.self) return (image, post.description) Firebase in a Widget

101. Architecture Swi!UI 2 Life Cycle Firebase Firestore Authentication Combine async/await

     Completion block WidgetKit

102. Authentication Photo by Conve&Kit on Unsplash

103. Authentication Photo by Eduardo Soares on Unsplash

104. Authentication Photo by Victor Freitas on Unsplash

105. 

106. Sign in the user Update the data model Secure users’

     data How to implement Firebase Authentication?

107. Anonymous Authentication “Guest” accounts, rather

108. func signIn() { registerStateListener() if Auth.auth().currentUser !& nil { Auth.auth().signInAnonymously()

     } } Anonymous Authentication
109. None

110. SignInWithAppleButton( onRequest: { !!' }, onCompletion: { result in !!'

     let appleIDToken = appleIDCredential.identityToken let idTokenString = String(data: appleIDToken, encoding: .utf8) let credential = OAuthProvider.credential(withProviderID: “apple.com", idToken: idTokenString, rawNonce: nonce) Auth.auth().signIn(with: credential) { (authResult, error) in if (error !( nil) { !!' } print(“User signed in") dismiss() } } ).frame(width: 280, height: 45, alignment: .center) Sign in with Apple

111. SignInWithAppleButton( onRequest: { !!' }, onCompletion: { result in !!'

     let appleIDToken = appleIDCredential.identityToken let idTokenString = String(data: appleIDToken, encoding: .utf8) let credential = OAuthProvider.credential(withProviderID: “apple.com", idToken: idTokenString, rawNonce: nonce) Auth.auth().signIn(with: credential) { (authResult, error) in if (error !( nil) { !!' } print(“User signed in") dismiss() } } ).frame(width: 280, height: 45, alignment: .center) Sign in with Apple

112. SignInWithAppleButton( onRequest: { !!' }, onCompletion: { result in !!'

     let appleIDToken = appleIDCredential.identityToken let idTokenString = String(data: appleIDToken, encoding: .utf8) let credential = OAuthProvider.credential(withProviderID: “apple.com", idToken: idTokenString, rawNonce: nonce) Auth.auth().signIn(with: credential) { (authResult, error) in if (error !( nil) { !!' } print(“User signed in") dismiss() } } ).frame(width: 280, height: 45, alignment: .center) Sign in with Apple

113. SignInWithAppleButton( onRequest: { !!' }, onCompletion: { result in !!'

     let appleIDToken = appleIDCredential.identityToken let idTokenString = String(data: appleIDToken, encoding: .utf8) let credential = OAuthProvider.credential(withProviderID: “apple.com", idToken: idTokenString, rawNonce: nonce) Auth.auth().signIn(with: credential) { (authResult, error) in if (error !( nil) { !!' } print(“User signed in") dismiss() } } ).frame(width: 280, height: 45, alignment: .center) Sign in with Apple

114. SignInWithAppleButton( onRequest: { !!' }, onCompletion: { result in !!'

     let appleIDToken = appleIDCredential.identityToken let idTokenString = String(data: appleIDToken, encoding: .utf8) let credential = OAuthProvider.credential(withProviderID: “apple.com", idToken: idTokenString, rawNonce: nonce) Auth.auth().signIn(with: credential) { (authResult, error) in if (error !( nil) { !!' } print(“User signed in") dismiss() } } ).frame(width: 280, height: 45, alignment: .center) Sign in with Apple Firebase SDK

115. SignInWithAppleButton( onRequest: { !!' }, onCompletion: { result in !!'

     let appleIDToken = appleIDCredential.identityToken let idTokenString = String(data: appleIDToken, encoding: .utf8) let credential = OAuthProvider.credential(withProviderID: “apple.com", idToken: idTokenString, rawNonce: nonce) Auth.auth().signIn(with: credential) { (authResult, error) in if (error !( nil) { !!' } print(“User signed in") dismiss() } } ).frame(width: 280, height: 45, alignment: .center) Sign in with Apple Firebase SDK

116. All books are stored in one single collection Which user

     do they belong to?

117. let query = db.collection("books") .whereField("userId", isEqualTo: self.userId) query .addSnapshotListener {

     [weak self] (querySnapsho guard let documents = querySnapshot!$documents els Signed in user

118. rules_version = '2'; service cloud.firestore { match /databases/{database}/documents { match

     /{document=**} { allow create: if request.auth !( null; allow read, update, delete: if request.auth !( null !) resource.data.userId !& request.auth.uid; } } } Security Rules Only signed-in users can create new documents Only owners may read and modify a document

119. Architecture Swi!UI 2 Life Cycle Firebase Firestore Authentication Combine async/await

     Completion block WidgetKit

120. Combine

121. auth!$signInAnonymously() let user = auth!$currentUser print("User signed in with user

     ID: \(user!$uid)") This might be nil

122. auth!$signInAnonymously() let user = auth!$currentUser print("User signed in with user

     ID: \(user!$uid)") auth!$signInAnonymously { result, error in guard let result = result else { return } print("User signed in with user ID: \(result.user.uid)") } Do this instead

123. auth!$signInAnonymously() let user = auth!$currentUser print("User signed in with user

     ID: \(user!$uid)") auth!$signInAnonymously { result, error in guard let result = result else { return } print("User signed in with user ID: \(result.user.uid)") } @Published var user: User? !!' auth!$signInAnonymously() .map{ $0.user } .replaceError(with: nil) .assign(to: &$user) Even better

124. Launched with Firebase 8.9.0 h"ps://github.com/%rebase/%rebase-ios-sdk/projects/3

125. Architecture Swi!UI 2 Life Cycle Firebase Firestore Authentication Combine async/await

     Completion block WidgetKit

126. async/await Photo by Stephen H on Unsplash

127. extension ArticleAnalyser { func process(url: String, completion: @escaping (Article) !"

     Void) { self.fetchArticle(from: url) { result in switch result { case .failure(let error): print(error.localizedDescription) case .success(let html): self.extractTitle(from: html) { result in switch result { case .failure(let error): print(error.localizedDescription) case .success(let title): self.extractText(from: html) { result in switch result { case .failure(let error): print(error.localizedDescription) case .success(let text): self.extractImage(from: url) { result in Problem: Callback Pyramid of Doom

128. extension AsyncArticleAnalyser { func process(url: String) async throws !" Article

     { let htmlText = try await fetchArticle(from: url) let text = try await extractText(from: htmlText) let title = try await extractTitle(from: htmlText) let imageUrl = try await extractImage(from: url) let tags = await inferTags(from: text) return Article(url: url, title: title, tags: tags, imageUrlString: imageUrl) } } Solution: Use async/await Swift 5.5

129. func fetchArticle(from url: String) async throws !" String { guard

     let url = URL(string: url) else { throw AnalyserError.badURL } return try await withUnsafeThrowingContinuation { continuation in URLSession.shared.downloadTask(with: url) { (localUrl, urlResponse, error) in guard let localUrl = localUrl else { continuation.resume(throwing: AnalyserError.badURL) return } if let htmlText = try? String(contentsOf: localUrl) { continuation.resume(returning: htmlText) } } .resume() } } Solution: Use async/await Swift 5.5

130. func fetchArticle(from url: String) async throws !" String { guard

     let url = URL(string: url) else { throw AnalyserError.badURL } return try await withUnsafeThrowingContinuation { continuation in URLSession.shared.downloadTask(with: url) { (localUrl, urlResponse, error) in guard let localUrl = localUrl else { continuation.resume(throwing: AnalyserError.badURL) return } if let htmlText = try? String(contentsOf: localUrl) { continuation.resume(returning: htmlText) } } .resume() } } Solution: Use async/await Swift 5.5

131. func fetchArticle(from url: String) async throws !" String { guard

     let url = URL(string: url) else { throw AnalyserError.badURL } return try await withUnsafeThrowingContinuation { continuation in URLSession.shared.downloadTask(with: url) { (localUrl, urlResponse, error) in guard let localUrl = localUrl else { continuation.resume(throwing: AnalyserError.badURL) return } if let htmlText = try? String(contentsOf: localUrl) { continuation.resume(returning: htmlText) } } .resume() } } Solution: Use async/await Swift 5.5

132. func fetchArticle(from url: String) async throws !" String { guard

     let url = URL(string: url) else { throw AnalyserError.badURL } return try await withUnsafeThrowingContinuation { continuation in URLSession.shared.downloadTask(with: url) { (localUrl, urlResponse, error) in guard let localUrl = localUrl else { continuation.resume(throwing: AnalyserError.badURL) return } if let htmlText = try? String(contentsOf: localUrl) { continuation.resume(returning: htmlText) } } .resume() } } Solution: Use async/await Swift 5.5

133. auth!$signInAnonymously { result, error in guard let result = result

     else { return } print("User signed in with user ID: \(result.user.uid)") } do { let result = try await Auth.auth().signIn(withEmail: email, password: password) print("User signed in with user ID: \(result.user.uid)") } catch { print(error) } Works with Firebase, too! Callback-style

134. Learn more h"ps://pete#riese.dev/async-await-in-swi! h"ps://www.youtube.com/watch?v=sEKw2BMcQtQ

135. Architecture Swi!UI 2 Life Cycle Firebase Firestore Authentication Combine async/await

     Completion block WidgetKit

136. Architecture Swi!UI 2 Life Cycle Firebase Firestore Authentication Combine async/await

     Completion block WidgetKit

137. Register now - it’s free! h"ps://io.google/2022/ Google I/O 2022

138. Thanks! @pete#riese h"ps://github.com/pete#riese/BookShelf Code @charlo"eCLiang

139. Credits %nish by Megan Chown from the Noun Project Time

     by Nikita Kozin from the Noun Project pipe by Komkrit Noenpoempisut from the Noun Project Passpo& by ProSymbols from the Noun Project spiral by Alexander Skowalsky from the Noun Project Architecture by Ervin Bolat from the Noun Project Firebase logos cou&esy h"ps://%rebase.google.com/brand-guidelines Firebase logos cou&esy h"ps://%rebase.google.com/brand-guidelines Thanks! Hea& by Roman from the Noun Project Dashboard by BomSymbols from the Noun Project

140. The End.