How to request access to the calendar when using SwiftUI? - events

I'm adopting SwiftUI for one of my previous apps, and at some point I need to add an event to the iOS calendar.
Doing some researches on both the Apple Developer Forums and Stack Overflow, I came up with the following solution, that makes use of the UIViewControllerRepresentable protocol in order to still be able to use UIViewControllers with SwiftUI (you can find below the links to the discussions, for your reference).
Discussion on the Apple Dev Forums:
https://forums.developer.apple.com/thread/120372
Discussion on Stack Overflow:
SwiftUI: Send email
I'm almost there, but what I'm missing now it's the control of the authorization status to access the device calendar, and to trigger the request for such authorization in case it's required.
In Swift this would be the function to invoke to trigger the request, but I'm not sure how to handle this in my EKEventWrapper.
func requestAccess(to entityType: EKEntityType,
completion: #escaping EKEventStoreRequestAccessCompletionHandler)
Any ideas?
Thanks a lot!
My solution up to this point:
import Foundation
import SwiftUI
import EventKitUI
let eventStore = EKEventStore()
struct EKEventWrapper: UIViewControllerRepresentable {
typealias UIViewControllerType = EKEventEditViewController
#Binding var isShowing: Bool
var theEvent = EKEvent.init(eventStore: eventStore)
func makeUIViewController(context: UIViewControllerRepresentableContext<EKEventWrapper>) -> EKEventEditViewController {
let calendar = EKCalendar.init(for: .event, eventStore: eventStore)
theEvent.startDate = Date()
theEvent.endDate = Date()
theEvent.title = "Meeting"
theEvent.calendar = calendar
let controller = EKEventEditViewController()
controller.event = theEvent
controller.eventStore = eventStore
controller.editViewDelegate = context.coordinator
return controller
}
func updateUIViewController(_ uiViewController: EKEventWrapper.UIViewControllerType, context: UIViewControllerRepresentableContext<EKEventWrapper>) {
//
}
func makeCoordinator() -> Coordinator {
return Coordinator(isShowing: $isShowing)
}
class Coordinator : NSObject, UINavigationControllerDelegate, EKEventEditViewDelegate {
#Binding var isShowing: Bool
init(isShowing: Binding<Bool>) {
_isShowing = isShowing
}
func eventEditViewController(_ controller: EKEventEditViewController, didCompleteWith action: EKEventEditViewAction) {
switch action {
case .canceled:
print("Canceled")
isShowing = false
case .saved:
print("Saved")
do {
try controller.eventStore.save(controller.event!, span: .thisEvent, commit: true)
}
catch {
print("Problem saving event")
}
isShowing = false
case .deleted:
print("Deleted")
isShowing = false
#unknown default:
print("I shouldn't be here")
isShowing = false
}
}
}
}

I believe the below will do this, I have tested it in SwiftUI using a button to action the function. First post ever so apologies If I am totally off the mark!
import SwiftUI
import EventKit
import EventKitUI
struct calaccess: View {
var eventstore = EKEventStore()
var body: some View {
func accesscalender(CalAccess: EKEventStore) {
let eventstore = EKEventStore()
eventstore.requestAccess(to: EKEntityType.event,completion:
{(granted, error) in
if !granted {
print("Access to store not granted")
}
}),,,,

Related

Create a share sheet in iOS 15 with swiftUI

I am trying to create a share sheet to share a Text, it was working fine in iOS 14 but in iOS 15 it tells me that
'windows' was deprecated in iOS 15.0: Use UIWindowScene.windows on a
relevant window scene instead.
how can I make it work on iOS 15 with SwiftUI
Button {
let TextoCompartido = "Hola 😀 "
let AV = UIActivityViewController(activityItems: [TextoCompartido], applicationActivities: nil)
UIApplication.shared.windows.first?.rootViewController?.present(AV, animated: true, completion: nil)
}
I think you would be best served using SwiftUI APIs directly. Generally, I would follow these steps.
Create SwiftUI View named ActivityView that adheres to UIViewControllerRepresentable. This will allow you to bring UIActivityViewController to SwiftUI.
Create an Identifiable struct to contain the text you'd like to display in the ActivityView. Making this type will allow you to use the SwiftUI sheet API and leverage SwiftUI state to tell the app when a new ActivityView to be shown.
Create an optional #State variable that will hold on to your Identifiable text construct. When this variable changes, the sheet API will perform the callback.
When the button is tapped, update the state of the variable set in step 3.
Use the sheet API to create an ActivityView which will be presented to your user.
The code below should help get you started.
import UIKit
import SwiftUI
// 1. Activity View
struct ActivityView: UIViewControllerRepresentable {
let text: String
func makeUIViewController(context: UIViewControllerRepresentableContext<ActivityView>) -> UIActivityViewController {
return UIActivityViewController(activityItems: [text], applicationActivities: nil)
}
func updateUIViewController(_ uiViewController: UIActivityViewController, context: UIViewControllerRepresentableContext<ActivityView>) {}
}
// 2. Share Text
struct ShareText: Identifiable {
let id = UUID()
let text: String
}
struct ContentView: View {
// 3. Share Text State
#State var shareText: ShareText?
var body: some View {
VStack {
Button("Show Activity View") {
// 4. New Identifiable Share Text
shareText = ShareText(text: "Hola 😀")
}
.padding()
}
// 5. Sheet to display Share Text
.sheet(item: $shareText) { shareText in
ActivityView(text: shareText.text)
}
}
}
For the future, iOS 16 will have the ShareLink view which works like this:
Gallery(...)
.toolbar {
ShareLink(item: image, preview: SharePreview("Birthday Effects"))
}
Source: https://developer.apple.com/videos/play/wwdc2022/10052/
Time code offset: 25 minutes 28 seconds
To avoid warning, change the way you retrieve the window scene.
Do the following:
Button {
let TextoCompartido = "Hola 😀 "
let AV = UIActivityViewController(activityItems: [TextoCompartido], applicationActivities: nil)
let scenes = UIApplication.shared.connectedScenes
let windowScene = scenes.first as? UIWindowScene
windowScene?.keyWindow?.rootViewController?.present(AV, animated: true, completion: nil)
}
Tested in in iOS 15 with SwiftUI
func shareViaActionSheet() {
if vedioData.vedioURL != nil {
let activityVC = UIActivityViewController(activityItems: [vedioData.vedioURL as Any], applicationActivities: nil)
UIApplication.shared.currentUIWindow()?.rootViewController?.present(activityVC, animated: true, completion: nil)
}
}
To avoid iOS 15 method deprecation warning use this extension
public extension UIApplication {
func currentUIWindow() -> UIWindow? {
let connectedScenes = UIApplication.shared.connectedScenes
.filter { $0.activationState == .foregroundActive }
.compactMap { $0 as? UIWindowScene }
let window = connectedScenes.first?
.windows
.first { $0.isKeyWindow }
return window
}
}
you could try the following using the answer from: How to get rid of message " 'windows' was deprecated in iOS 15.0: Use UIWindowScene.windows on a relevant window scene instead" with AdMob banner?
Note that your code works for me, but the compiler give the deprecation warning.
public extension UIApplication {
func currentUIWindow() -> UIWindow? {
let connectedScenes = UIApplication.shared.connectedScenes
.filter({
$0.activationState == .foregroundActive})
.compactMap({$0 as? UIWindowScene})
let window = connectedScenes.first?
.windows
.first { $0.isKeyWindow }
return window
}
}
struct ContentView: View {
let TextoCompartido = "Hola 😀 "
var body: some View {
Button(action: {
let AV = UIActivityViewController(activityItems: [TextoCompartido], applicationActivities: nil)
UIApplication.shared.currentUIWindow()?.rootViewController?.present(AV, animated: true, completion: nil)
// This works for me, but the compiler give the deprecation warning
// UIApplication.shared.windows.first?.rootViewController?.present(AV, animated: true, completion: nil)
}) {
Text("Hola click me")
}
}
}

Implementing AdMob Interstitial Ads in SwiftUI (5) and Xcode (12.4)

I am working on implementing Interstitial ads in my app and running into some confusion with the docs provided by Admob and the new SwiftUI app structure.
Here is the app.swift file, showing that I've implemented the GoogleMobileAds and started it in the didFinishLaunchingWithOptions method.
import SwiftUI
import GoogleMobileAds
#main
struct adamsCalcApp: App {
var calculator = Calculator()
#UIApplicationDelegateAdaptor(AppDelegate.self) var appDelegate
var body: some Scene {
WindowGroup {
ContentView().environmentObject(calculator)
}
}
}
class AppDelegate: NSObject, UIApplicationDelegate {
func application(_ application: UIApplication, didFinishLaunchingWithOptions launchOptions: [UIApplication.LaunchOptionsKey : Any]? = nil) -> Bool {
// Setup google admob instance
GADMobileAds.sharedInstance().start(completionHandler: nil)
return true
}
}
In my ContentView.swift File, I have the interstitial variable created like...
#State var interstitial: GADInterstitialAd?
Then on the main stack in the view, I call onAppear(perform: ) to load the ad, however I keep getting this error.
.onAppear(perform: {
let request = GADRequest()
GADInterstitialAd.load(withAdUnitID:"ca-app-pub-3940256099942544/4411468910",
request: request,
completionHandler: { [self] ad, error in
if let error = error {
return
}
interstitial = ad
interstitial?.fullScreenContentDelegate = self
}
)
})
"Cannot assign value of type 'ContentView' to type
'GADFullScreenContentDelegate?'"
I am feeling a bit clueless after trying a few different workarounds and trying to look up a setup that is like mine, AdMob docs still show how to implement with class ViewControllers and I would like to figure out how to do this is SwiftUI.
import SwiftUI
import GoogleMobileAds
import AppTrackingTransparency
import AdSupport
class AdsManager: NSObject, ObservableObject {
private struct AdMobConstant {
static let interstitial1ID = "..."
}
final class Interstitial: NSObject, GADFullScreenContentDelegate, ObservableObject {
private var interstitial: GADInterstitialAd?
override init() {
super.init()
requestInterstitialAds()
}
func requestInterstitialAds() {
let request = GADRequest()
request.scene = UIApplication.shared.connectedScenes.first as? UIWindowScene
ATTrackingManager.requestTrackingAuthorization(completionHandler: { status in
GADInterstitialAd.load(withAdUnitID: AdMobConstant.interstitial1ID, request: request, completionHandler: { [self] ad, error in
if let error = error {
print("Failed to load interstitial ad with error: \(error.localizedDescription)")
return
}
interstitial = ad
interstitial?.fullScreenContentDelegate = self
})
})
}
func showAd() {
let root = UIApplication.shared.windows.last?.rootViewController
if let fullScreenAds = interstitial {
fullScreenAds.present(fromRootViewController: root!)
} else {
print("not ready")
}
}
}
}
class AdsViewModel: ObservableObject {
static let shared = AdsViewModel()
#Published var interstitial = AdsManager.Interstitial()
#Published var showInterstitial = false {
didSet {
if showInterstitial {
interstitial.showAd()
showInterstitial = false
} else {
interstitial.requestInterstitialAds()
}
}
}
}
#main
struct YourApp: App {
let adsVM = AdsViewModel.shared
init() {
GADMobileAds.sharedInstance().start(completionHandler: nil)
}
var body: some Scene {
WindowGroup {
ContentView()
.environmentObject(adsVM)
}
}
Toggle the showInterstitial parameter in the AdsViewModel anywhere in the application and the advertisement will be shown.
In order to use the Admob docs with the newest SwiftUI release, you need to change this line...
.onAppear(perform: {
let request = GADRequest()
GADInterstitialAd.load(withAdUnitID:"ca-app-pub-3940256099942544/4411468910",
request: request,
completionHandler: { [self] ad, error in
if let error = error {
return
}
// Change these two lines of code
interstitial = ad
interstitial?.fullScreenContentDelegate = self
// To...
interstitial = ad
let root = UIApplication.shared.windows.first?.rootViewController
self.interstitial!.present(fromRootViewController: root!)
}
)
})

Swifui Realmdatabase Listview crashes

Good evening,
I'm implementing a Realm Database with SwiftUI.
The Database is made of a table containing "Projects" and a table containing "Measures" (relation one-to-many).
The main view displays the project list and "Measureview" displays the measures related to the project selected.
When I select a project, the measures list is displayed and then impossible to go back, the app crashes (simulator and real device).
Xcode points AppDelegate file : Thread 1: EXC_BAD_ACCESS (code=2, address=0x7ffedfd5cfd8)
I know that 4/5 months ago, some developers experienced this issue but I suppose that currently Apple fix the problem.
Please find below the relevant code :
Realm part :
import Foundation
import RealmSwift
import Combine
class Project : Object, Identifiable {
#objc dynamic var ProjectName = "" // primary key
#objc dynamic var ProjectCategorie = ""
#objc dynamic var ProjectCommentaire = ""
let Measures = List<Measure>() // one to many
override static func primaryKey() -> String? {
return "ProjectName"
}
}
class Measure : Object, Identifiable {
// #objc dynamic var id_Measure = UUID().uuidString // primary key
#objc dynamic var MeasureName = ""
#objc dynamic var MeasureDetail = ""
#objc dynamic var MeasureResult = ""
override static func primaryKey() -> String? {
return "MeasureName"
}
}
func createProject (_ title:String,_ categorie:String, _ commentaire:String) {
let realm = try! Realm()
let proj = Project()
proj.ProjectName = title
proj.ProjectCategorie = categorie
proj.ProjectCommentaire = commentaire
try! realm.write {
realm.add(proj)
}
}
//****************************************************************
class BindableResults<Element>: ObservableObject where Element: RealmSwift.RealmCollectionValue {
let didChange = PassthroughSubject<Void, Never>()
let results: Results<Element>
private var token: NotificationToken!
init(results: Results<Element>) {
self.results = results
lateInit()
}
func lateInit() {
token = results.observe { _ in
self.didChange.send(())
}
}
deinit {
token.invalidate()
}
}
Contentview :
struct ContentView : View {
#ObservedObject var Proj = BindableResults(results: try! Realm().objects(Project.self))
var body: some View {
NavigationView{
List(Proj.results) { item in
NavigationLink(destination: MeasureView(Pro: item) ){
ContenRowUI(Proj :item)
}
}
}
.navigationBarTitle(Text("Project List"))
}
}
Measure view :
struct MeasureView: View {
var Pro = Project() //= Project()
var body: some View {
NavigationView {
List(Pro.Measures) { item in
Text("Detail: \(item.MeasureDetail)")
}
.navigationBarTitle(Text("Measure"))
}
}
}
Additional information, if I replace Measureview by a simple textview, the behaviour is very weird :
I select a Project, the application shows the textview and goes back automatically to the main list (project list)
If someone could help me, I would be grateful.
Thanks a lot for your support.
Jeff

SwiftUI Load View from SceneDelegate sceneDidBecomeActive

I'm trying to understand how to load a SwiftUI view from Swift function code. In this
case specifically, I want to load a view when returning from the background state to
cover sensitive data. I have created a biometric login and that works fine - pure
SwiftUI views for the app. When I put the app into the background and return, the
FaceID works as expected, but the underlying screen is visible. This is a generalized
question too - how can you load any SwiftUI view from any Swift function.
func sceneDidBecomeActive(_ scene: UIScene) {
if userDefaultsManager.wentToBackground {
if userDefaultsManager.enableBiometrics {
BiometricsLogin(userDefaultsManager: userDefaultsManager).authenticate()
//what I want is something like:
//BiometricsLogin(userDefaultsManager: userDefaultsManager)
//kinda like you would do in a TabView
//that would run the authentication just like starting the app
userDefaultsManager.wentToBackground = false
}
}
}
And the login code is pretty generic:
struct BiometricsLogin: View {
#ObservedObject var userDefaultsManager: UserDefaultsManager
var body: some View {
NavigationView {
VStack {
Image("CoifMeCrop180")
.onAppear {
self.authenticate()
}
}//vstack
}//nav
}
func authenticate() {
let context = LAContext()
var error: NSError?
if context.canEvaluatePolicy(.deviceOwnerAuthenticationWithBiometrics, error: &error) {
let reason = "The app uses Biometrics to unlock you data"
context.evaluatePolicy(.deviceOwnerAuthentication, localizedReason: reason) { (success, authenticationError)
in
DispatchQueue.main.async {
if success {
self.userDefaultsManager.isAuthenticated = true
self.userDefaultsManager.selectedTab = 1
} else {
if self.userDefaultsManager.enableBiometrics {
self.userDefaultsManager.isAuthenticated = false
self.userDefaultsManager.selectedTab = 3
} else {
self.userDefaultsManager.isAuthenticated = false
self.userDefaultsManager.selectedTab = 1
}
}
}
}
} else {
//no biometrics - deal with this elsewhere
//consider an alert here
}
}//authenticate
}
I also tried using a hosting controller like this, but it did not work either. Same
issue, the authentication worked but the data was visible.
//this does not work
let controller = UIHostingController(rootView: BiometricsLogin(userDefaultsManager: userDefaultsManager))
self.window!.addSubview(controller.view)
self.window?.makeKeyAndVisible()
Any guidance would be appreciated. Xcode 11.3.1 (11C504)
Here is possible approach
In sceneDidBecomeActive add presenting new controller with authentication in full screen to hide sensitive content
func sceneDidBecomeActive(_ scene: UIScene) {
let controller = UIHostingController(rootView: BiometricsLogin(userDefaultsManager: userDefaultsManager))
controller.modalPresentationStyle = .fullScreen
self.window?.rootViewController?.present(controller, animated: false)
}
now it needs to dismiss it when authentication will be done, so add notification for that purpose...
extension SceneDelegate {
static let didAuthenticate = Notification.Name(rawValue: "didAuthenticate")
}
... and subscriber for it in SceneDelegate
class SceneDelegate: UIResponder, UIWindowSceneDelegate {
var window: UIWindow?
private var authenticateObserver: AnyCancellable?
func scene(_ scene: UIScene, willConnectTo session: UISceneSession, options connectionOptions: UIScene.ConnectionOptions) {
let contentView = ContentView()
if let windowScene = scene as? UIWindowScene {
self.authenticateObserver = NotificationCenter.default.publisher(for: SceneDelegate.didAuthenticate)
.sink { _ in
self.window?.rootViewController?.dismiss(animated: true)
}
let window = UIWindow(windowScene: windowScene)
...
when authentication is done just post didAuthenticate notification to dismiss top controller
DispatchQueue.main.async {
if success {
self.userDefaultsManager.isAuthenticated = true
self.userDefaultsManager.selectedTab = 1
} else {
if self.userDefaultsManager.enableBiometrics {
self.userDefaultsManager.isAuthenticated = false
self.userDefaultsManager.selectedTab = 3
} else {
self.userDefaultsManager.isAuthenticated = false
self.userDefaultsManager.selectedTab = 1
}
}
NotificationCenter.default.post(name: SceneDelegate.didAuthenticate, object: nil)
}

How to display Game Center leaderboard with SwiftUI

I created a tester app to test adding a GameCenter leaderboard to a simple SwiftUI game I am creating. I have been unable to figure out how to display the Game Center leaderboard with all the scores.
I have created a class containing all the Game Center functions (authentication and adding score to the leaderboard. This is called from the main ContentView view. I can't figure out how to make it show the leaderboard (or even the gamecenter login screen if the player isn't already logged in.)
This is my GameCenterManager class:
class GameCenterManager {
var gcEnabled = Bool() // Check if the user has Game Center enabled
var gcDefaultLeaderBoard = String() // Check the default leaderboardID
var score = 0
let LEADERBOARD_ID = "grp.colorMatcherLeaderBoard_1" //Leaderboard ID from Itunes Connect
// MARK: - AUTHENTICATE LOCAL PLAYER
func authenticateLocalPlayer() {
let localPlayer: GKLocalPlayer = GKLocalPlayer.local
localPlayer.authenticateHandler = {(ViewController, error) -> Void in
if((ViewController) != nil) {
print("User is not logged into game center")
} else if (localPlayer.isAuthenticated) {
// 2. Player is already authenticated & logged in, load game center
self.gcEnabled = true
// Get the default leaderboard ID
localPlayer.loadDefaultLeaderboardIdentifier(completionHandler: { (leaderboardIdentifer, error) in
if error != nil { print(error ?? "error1")
} else { self.gcDefaultLeaderBoard = leaderboardIdentifer! }
})
print("Adding GameCenter user was a success")
} else {
// 3. Game center is not enabled on the users device
self.gcEnabled = false
print("Local player could not be authenticated!")
print(error ?? "error2")
}
}
} //authenticateLocalPlayer()
func submitScoreToGC(_ score: Int){
let bestScoreInt = GKScore(leaderboardIdentifier: LEADERBOARD_ID)
bestScoreInt.value = Int64(score)
GKScore.report([bestScoreInt]) { (error) in
if error != nil {
print(error!.localizedDescription)
} else {
print("Best Score submitted to your Leaderboard!")
}
}
}//submitScoreToGc()
}
and here is the ContentView struct:
struct ContentView: View {
//GameCenter
init() {
self.gameCenter = GameCenterManager()
self.gameCenter.authenticateLocalPlayer()
}
#State var score = 0
var gcEnabled = Bool() //Checks if the user had enabled GameCenter
var gcDefaultLeaderboard = String() //Checks the default leaderboard ID
let gameCenter: GameCenterManager
/*End GameCenter Variables */
var body: some View {
HStack {
Text("Hello, world!")
Button(action: {
self.score += 1
print("Score increased by 10. It is now \(self.score)")
self.gameCenter.submitScoreToGC(self.score)
}) {
Text("Increase Score")
}
}
}
}
Would greatly appreciate any help in fixing the problem.
I have a fix.
I use Game Center successfully in my SwiftUI App Sound Matcher. Code snippets to follow.
The code doesn't exactly follow the SwiftUI declarative philosophy but it works perfectly. I added snippets to SceneDelegate and ContentView plus used I used a GameKitHelper class similar to the one Thomas created for his test app. I based my version on code I found on raywenderlich.com.
I actually tried using a struct conforming to UIViewControllerRepresentable as my first attempt, following the same line of thought as bg2b, however it kept complaining that the game centre view controller needed to be presented modally. Eventually I gave up and tried my current more successful approach.
For SwiftUI 1.0 and iOS 13
class SceneDelegate: UIResponder, UIWindowSceneDelegate {
let contentView = ContentView()
.environmentObject(GameKitHelper.sharedInstance) // publish enabled state
func scene(_ scene: UIScene, willConnectTo session: UISceneSession,
options connectionOptions: UIScene.ConnectionOptions) {
if let windowScene = scene as? UIWindowScene {
let window = UIWindow(windowScene: windowScene)
window.rootViewController = UIHostingController(rootView: contentView)
// new code to create listeners for the messages
// you will be sending later
PopupControllerMessage.PresentAuthentication
.addHandlerForNotification(
self,
handler: #selector(SceneDelegate
.showAuthenticationViewController))
PopupControllerMessage.GameCenter
.addHandlerForNotification(
self,
handler: #selector(SceneDelegate
.showGameCenterViewController))
// now we are back to the standard template
// generated when your project was created
self.window = window
window.makeKeyAndVisible()
}
}
// pop's up the leaderboard and achievement screen
#objc func showGameCenterViewController() {
if let gameCenterViewController =
GameKitHelper.sharedInstance.gameCenterViewController {
self.window?.rootViewController?.present(
gameCenterViewController,
animated: true,
completion: nil)
}
}
// pop's up the authentication screen
#objc func showAuthenticationViewController() {
if let authenticationViewController =
GameKitHelper.sharedInstance.authenticationViewController {
self.window?.rootViewController?.present(
authenticationViewController, animated: true)
{ GameKitHelper.sharedInstance.enabled =
GameKitHelper.sharedInstance.gameCenterEnabled }
}
}
}
// content you want your app to display goes here
struct ContentView: View {
#EnvironmentObject var gameCenter : GameKitHelper
#State private var isShowingGameCenter = false { didSet {
PopupControllerMessage
.GameCenter
.postNotification() }}
var body: some View {
VStack {
if self.gameCenter.enabled
{
Button(action:{ self.isShowingGameCenter.toggle()})
{ Text(
"Press to show leaderboards and achievements")}
}
// The authentication popup will appear when you first enter
// the view
}.onAppear() {GameKitHelper.sharedInstance
.authenticateLocalPlayer()}
}
}
import GameKit
import UIKit
// Messages sent using the Notification Center to trigger
// Game Center's Popup screen
public enum PopupControllerMessage : String
{
case PresentAuthentication = "PresentAuthenticationViewController"
case GameCenter = "GameCenterViewController"
}
extension PopupControllerMessage
{
public func postNotification() {
NotificationCenter.default.post(
name: Notification.Name(rawValue: self.rawValue),
object: self)
}
public func addHandlerForNotification(_ observer: Any,
handler: Selector) {
NotificationCenter.default .
addObserver(observer, selector: handler, name:
NSNotification.Name(rawValue: self.rawValue), object: nil)
}
}
// based on code from raywenderlich.com
// helper class to make interacting with the Game Center easier
open class GameKitHelper: NSObject, ObservableObject, GKGameCenterControllerDelegate {
public var authenticationViewController: UIViewController?
public var lastError: Error?
private static let _singleton = GameKitHelper()
public class var sharedInstance: GameKitHelper {
return GameKitHelper._singleton
}
private override init() {
super.init()
}
#Published public var enabled :Bool = false
public var gameCenterEnabled : Bool {
return GKLocalPlayer.local.isAuthenticated }
public func authenticateLocalPlayer () {
let localPlayer = GKLocalPlayer.local
localPlayer.authenticateHandler = {(viewController, error) in
self.lastError = error as NSError?
self.enabled = GKLocalPlayer.local.isAuthenticated
if viewController != nil {
self.authenticationViewController = viewController
PopupControllerMessage
.PresentAuthentication
.postNotification()
}
}
}
public var gameCenterViewController : GKGameCenterViewController? { get {
guard gameCenterEnabled else {
print("Local player is not authenticated")
return nil }
let gameCenterViewController = GKGameCenterViewController()
gameCenterViewController.gameCenterDelegate = self
gameCenterViewController.viewState = .achievements
return gameCenterViewController
}}
open func gameCenterViewControllerDidFinish(_
gameCenterViewController: GKGameCenterViewController) {
gameCenterViewController.dismiss(
animated: true, completion: nil)
}
}
Update: For SwiftUI 2.0 and iOS 14 the code is lot easier
import GameKit
enum Authenticate
{
static func user() {
let localPlayer = GKLocalPlayer.local
localPlayer.authenticateHandler = { _, error in
guard error == nil else {
print(error?.localizedDescription ?? "")
return
}
GKAccessPoint.shared.location = .topLeading
GKAccessPoint.shared.isActive =
localPlayer.isAuthenticated
}
}
}
import SwiftUI
// content you want your app to display goes here
struct ContentView: View {
var body: some View {
Text( "Start Game")
// The authentication popup will appear when you first enter
// the view
}.onAppear() { Authenticate.user()}
}
}
EDIT 2023: as mentioned in comments, GKScore is now deprecated. I don't have an updated solution to present.
Partial answer for you here. I'm able to download leaderboard scores and display them in a SwiftUI list provided the device (or simulator) is logged into iCloud and has GameCenter already enabled in settings. I have not attempted to make a gameCenter authentication view controller appear if that is not the case.
Thank you for the code in your question. I used your GameCenterManager() but put it in my AppDelegate:
let gameCenter = GameCenterManager()
Below is my ShowRankings.swift SwiftUI View. I'm able to successfully authenticate and get the scores. But I still have "anomalies". The first time I run this (in simulator) I get the expected "User is not logged into Game Center" error indicating the ViewController in your GameCenterManager is not nil (I never even attempt to display it). But then I'm able to successfully get the scores and display them in a list.
import SwiftUI
import GameKit
struct ShowRankings: View {
let appDelegate = UIApplication.shared.delegate as! AppDelegate
let leaderBoard = GKLeaderboard()
#State var scores: [GKScore] = []
var body: some View {
VStack {
Button(action: {
self.updateLeader()
}) {
Text("Refresh leaderboard")
}
List(scores, id: \.self) { score in
Text("\(score.player.alias) \(score.value)")
}
}.onAppear() {
self.appDelegate.gameCenter.authenticateLocalPlayer()
self.updateLeader()
}
}
func updateLeader() {
let leaderBoard: GKLeaderboard = GKLeaderboard()
leaderBoard.identifier = "YOUR_LEADERBOARD_ID_HERE"
leaderBoard.timeScope = .allTime
leaderBoard.loadScores { (scores, error) in
if let error = error {
debugPrint("leaderboard loadScores error \(error)")
} else {
guard let scores = scores else { return }
self.scores = scores
}
}
}
}
An alternative solution is to create a UIViewControllerRepresentable for GameCenter which takes a leaderboard ID to open. This makes it simple to open a specific leader board.
public struct GameCenterView: UIViewControllerRepresentable {
let viewController: GKGameCenterViewController
public init(leaderboardID : String?) {
if leaderboardID != nil {
self.viewController = GKGameCenterViewController(leaderboardID: leaderboardID!, playerScope: GKLeaderboard.PlayerScope.global, timeScope: GKLeaderboard.TimeScope.allTime)
}
else{
self.viewController = GKGameCenterViewController(state: GKGameCenterViewControllerState.leaderboards)
}
}
public func makeUIViewController(context: Context) -> GKGameCenterViewController {
let gkVC = viewController
gkVC.gameCenterDelegate = context.coordinator
return gkVC
}
public func updateUIViewController(_ uiViewController: GKGameCenterViewController, context: Context) {
return
}
public func makeCoordinator() -> GKCoordinator {
return GKCoordinator(self)
}
}
public class GKCoordinator: NSObject, GKGameCenterControllerDelegate {
var view: GameCenterView
init(_ gkView: GameCenterView) {
self.view = gkView
}
public func gameCenterViewControllerDidFinish(_ gameCenterViewController: GKGameCenterViewController) {
gameCenterViewController.dismiss(animated: true, completion: nil)
}
}
To use just add the below wherever it is needed to display a leaderboard.
GameCenterView(leaderboardID: "leaderBoardID")

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