I would like to add leaderboards to my SwiftUI app.
I can't find any examples of using loadEntries to load leaderboard values.
I tried the following...
let leaderBoard: GKLeaderboard = GKLeaderboard()
leaderBoard.identifier = "YOUR_LEADERBOARD_ID_HERE"
leaderBoard.timeScope = .allTime
leaderBoard.loadScores { (scores, error) in ...
This results in the following warnings:
'identifier' was deprecated in iOS 14.0: Use
loadEntriesForPlayerScope:timeScope:range:completionHandler: instead.
'timeScope' was deprecated in iOS 14.0: Use
loadEntriesForPlayerScope:timeScope:range:completionHandler: instead.
'loadScores(completionHandler:)' was deprecated in iOS 14.0: Use
loadEntriesForPlayerScope:timeScope:range:completionHandler:.
using loadEntriesForPlayerScope results in the following warning:
'loadEntriesForPlayerScope(_:timeScope:range:completionHandler:)' has
been renamed to 'loadEntries(for:timeScope:range:completionHandler:)'
Using loadEntries I don't know how to specify the leaderboard identifier.
Here is simple demo of possible approach - put everything in view model and load scores on view appear.
import GameKit
class BoardModel: ObservableObject {
private var board: GKLeaderboard?
#Published var localPlayerScore: GKLeaderboard.Entry?
#Published var topScores: [GKLeaderboard.Entry]?
func load() {
if nil == board {
GKLeaderboard.loadLeaderboards(IDs: ["YOUR_LEADERBOARD_ID_HERE"]) { [weak self] (boards, error) in
self?.board = boards?.first
self?.updateScores()
}
} else {
self.updateScores()
}
}
func updateScores() {
board?.loadEntries(for: .global, timeScope: .allTime, range: NSRange(location: 1, length: 10),
completionHandler: { [weak self] (local, entries, count, error) in
DispatchQueue.main.async {
self?.localPlayerScore = local
self?.topScores = entries
}
})
}
}
struct DemoGameboardview: View {
#StateObject var vm = BoardModel()
var body: some View {
List {
ForEach(vm.topScores ?? [], id: \.self) { item in
HStack {
Text(item.player.displayName)
Spacer()
Text(item.formattedScore)
}
}
}
.onAppear {
vm.load()
}
}
}
I might be stating the obvious but have you looked at the WWDC20 videos?
Usually when there are big changes like this they cover it during WWDC that year.
Tap into Game Center: Leaderboards, Achievements, and Multiplayer
Tap into Game Center: Dashboard, Access Point, and Profile
I haven't looked at the videos but the documentation eludes that identifier might be replaced by var baseLeaderboardID: String
Related
I have a form where the user enters their address. While they can always enter it manually, I also wanted to provide them with an easy solution with auto complete so that they could just start typing their address and then tap on the correct one from the list and have it auto populate the various fields.
I started by working off of jnpdx's Swift5 solution - https://stackoverflow.com/a/67131376/11053343
However, there are two issues that I cannot seem to solve:
I need the results to be limited to the United States only (not just the continental US, but the entire United States including Alaska, Hawaii, and Puerto Rico). I am aware of how MKCoordinateRegion works with the center point and then the zoom spread, but it doesn't seem to work on the results of the address search.
The return of the results provides only a title and subtitle, where I need to actually extract all the individual address information and populate my variables (i.e. address, city, state, zip, and zip ext). If the user has an apt or suite number, they would then fill that in themselves. My thought was to create a function that would run when the button is tapped, so that the variables are assigned based off of the user's selection, but I have no idea how to extract the various information required. Apple's docs are terrible as usual and I haven't found any tutorials explaining how to do this.
This is for the latest SwiftUI and XCode (ios15+).
I created a dummy form for testing. Here's what I have:
import SwiftUI
import Combine
import MapKit
class MapSearch : NSObject, ObservableObject {
#Published var locationResults : [MKLocalSearchCompletion] = []
#Published var searchTerm = ""
private var cancellables : Set<AnyCancellable> = []
private var searchCompleter = MKLocalSearchCompleter()
private var currentPromise : ((Result<[MKLocalSearchCompletion], Error>) -> Void)?
override init() {
super.init()
searchCompleter.delegate = self
searchCompleter.region = MKCoordinateRegion()
searchCompleter.resultTypes = MKLocalSearchCompleter.ResultType([.address])
$searchTerm
.debounce(for: .seconds(0.5), scheduler: RunLoop.main)
.removeDuplicates()
.flatMap({ (currentSearchTerm) in
self.searchTermToResults(searchTerm: currentSearchTerm)
})
.sink(receiveCompletion: { (completion) in
//handle error
}, receiveValue: { (results) in
self.locationResults = results
})
.store(in: &cancellables)
}
func searchTermToResults(searchTerm: String) -> Future<[MKLocalSearchCompletion], Error> {
Future { promise in
self.searchCompleter.queryFragment = searchTerm
self.currentPromise = promise
}
}
}
extension MapSearch : MKLocalSearchCompleterDelegate {
func completerDidUpdateResults(_ completer: MKLocalSearchCompleter) {
currentPromise?(.success(completer.results))
}
func completer(_ completer: MKLocalSearchCompleter, didFailWithError error: Error) {
//currentPromise?(.failure(error))
}
}
struct MapKit_Interface: View {
#StateObject private var mapSearch = MapSearch()
#State private var address = ""
#State private var addrNum = ""
#State private var city = ""
#State private var state = ""
#State private var zip = ""
#State private var zipExt = ""
var body: some View {
List {
Section {
TextField("Search", text: $mapSearch.searchTerm)
ForEach(mapSearch.locationResults, id: \.self) { location in
Button {
// Function code goes here
} label: {
VStack(alignment: .leading) {
Text(location.title)
.foregroundColor(Color.white)
Text(location.subtitle)
.font(.system(.caption))
.foregroundColor(Color.white)
}
} // End Label
} // End ForEach
} // End Section
Section {
TextField("Address", text: $address)
TextField("Apt/Suite", text: $addrNum)
TextField("City", text: $city)
TextField("State", text: $state)
TextField("Zip", text: $zip)
TextField("Zip-Ext", text: $zipExt)
} // End Section
} // End List
} // End var Body
} // End Struct
Since no one has responded, I, and my friend Tolstoy, spent a lot of time figuring out the solution and I thought I would post it for anyone else who might be interested. Tolstoy wrote a version for the Mac, while I wrote the iOS version shown here.
Seeing as how Google is charging for usage of their API and Apple is not, this solution gives you address auto-complete for forms. Bear in mind it won't always be perfect because we are beholden to Apple and their maps. Likewise, you have to turn the address into coordinates, which you then turn into a placemark, which means there will be some addresses that may change when tapped from the completion list. Odds are this won't be an issue for 99.9% of users, but thought I would mention it.
At the time of this writing, I am using XCode 13.2.1 and SwiftUI for iOS 15.
I organized it with two Swift files. One to hold the class/struct (AddrStruct.swift) and the other which is the actual view in the app.
AddrStruct.swift
import SwiftUI
import Combine
import MapKit
import CoreLocation
class MapSearch : NSObject, ObservableObject {
#Published var locationResults : [MKLocalSearchCompletion] = []
#Published var searchTerm = ""
private var cancellables : Set<AnyCancellable> = []
private var searchCompleter = MKLocalSearchCompleter()
private var currentPromise : ((Result<[MKLocalSearchCompletion], Error>) -> Void)?
override init() {
super.init()
searchCompleter.delegate = self
searchCompleter.resultTypes = MKLocalSearchCompleter.ResultType([.address])
$searchTerm
.debounce(for: .seconds(0.2), scheduler: RunLoop.main)
.removeDuplicates()
.flatMap({ (currentSearchTerm) in
self.searchTermToResults(searchTerm: currentSearchTerm)
})
.sink(receiveCompletion: { (completion) in
//handle error
}, receiveValue: { (results) in
self.locationResults = results.filter { $0.subtitle.contains("United States") } // This parses the subtitle to show only results that have United States as the country. You could change this text to be Germany or Brazil and only show results from those countries.
})
.store(in: &cancellables)
}
func searchTermToResults(searchTerm: String) -> Future<[MKLocalSearchCompletion], Error> {
Future { promise in
self.searchCompleter.queryFragment = searchTerm
self.currentPromise = promise
}
}
}
extension MapSearch : MKLocalSearchCompleterDelegate {
func completerDidUpdateResults(_ completer: MKLocalSearchCompleter) {
currentPromise?(.success(completer.results))
}
func completer(_ completer: MKLocalSearchCompleter, didFailWithError error: Error) {
//could deal with the error here, but beware that it will finish the Combine publisher stream
//currentPromise?(.failure(error))
}
}
struct ReversedGeoLocation {
let streetNumber: String // eg. 1
let streetName: String // eg. Infinite Loop
let city: String // eg. Cupertino
let state: String // eg. CA
let zipCode: String // eg. 95014
let country: String // eg. United States
let isoCountryCode: String // eg. US
var formattedAddress: String {
return """
\(streetNumber) \(streetName),
\(city), \(state) \(zipCode)
\(country)
"""
}
// Handle optionals as needed
init(with placemark: CLPlacemark) {
self.streetName = placemark.thoroughfare ?? ""
self.streetNumber = placemark.subThoroughfare ?? ""
self.city = placemark.locality ?? ""
self.state = placemark.administrativeArea ?? ""
self.zipCode = placemark.postalCode ?? ""
self.country = placemark.country ?? ""
self.isoCountryCode = placemark.isoCountryCode ?? ""
}
}
For testing purposes, I called my main view file Test.swift. Here's a stripped down version for reference.
Test.swift
import SwiftUI
import Combine
import CoreLocation
import MapKit
struct Test: View {
#StateObject private var mapSearch = MapSearch()
func reverseGeo(location: MKLocalSearchCompletion) {
let searchRequest = MKLocalSearch.Request(completion: location)
let search = MKLocalSearch(request: searchRequest)
var coordinateK : CLLocationCoordinate2D?
search.start { (response, error) in
if error == nil, let coordinate = response?.mapItems.first?.placemark.coordinate {
coordinateK = coordinate
}
if let c = coordinateK {
let location = CLLocation(latitude: c.latitude, longitude: c.longitude)
CLGeocoder().reverseGeocodeLocation(location) { placemarks, error in
guard let placemark = placemarks?.first else {
let errorString = error?.localizedDescription ?? "Unexpected Error"
print("Unable to reverse geocode the given location. Error: \(errorString)")
return
}
let reversedGeoLocation = ReversedGeoLocation(with: placemark)
address = "\(reversedGeoLocation.streetNumber) \(reversedGeoLocation.streetName)"
city = "\(reversedGeoLocation.city)"
state = "\(reversedGeoLocation.state)"
zip = "\(reversedGeoLocation.zipCode)"
mapSearch.searchTerm = address
isFocused = false
}
}
}
}
// Form Variables
#FocusState private var isFocused: Bool
#State private var btnHover = false
#State private var isBtnActive = false
#State private var address = ""
#State private var city = ""
#State private var state = ""
#State private var zip = ""
// Main UI
var body: some View {
VStack {
List {
Section {
Text("Start typing your street address and you will see a list of possible matches.")
} // End Section
Section {
TextField("Address", text: $mapSearch.searchTerm)
// Show auto-complete results
if address != mapSearch.searchTerm && isFocused == false {
ForEach(mapSearch.locationResults, id: \.self) { location in
Button {
reverseGeo(location: location)
} label: {
VStack(alignment: .leading) {
Text(location.title)
.foregroundColor(Color.white)
Text(location.subtitle)
.font(.system(.caption))
.foregroundColor(Color.white)
}
} // End Label
} // End ForEach
} // End if
// End show auto-complete results
TextField("City", text: $city)
TextField("State", text: $state)
TextField("Zip", text: $zip)
} // End Section
.listRowSeparator(.visible)
} // End List
} // End Main VStack
} // End Var Body
} // End Struct
struct Test_Previews: PreviewProvider {
static var previews: some View {
Test()
}
}
If anyone is wondering how to generate global results, change the code from this:
self.locationResults = results.filter{$0.subtitle.contains("United States")}
to this in Address Structure file:
self.locationResults = results
I wrote a demo program to display pins on a map in SwiftUI following this and this tutorial and it worked no problem. Then when I applied this same technique to my app, I get an error that the type cannot conform to 'MapAnnotationProtocol'.
Here's my code:
import SwiftUI
import MapKit
struct MapLocationView: View {
#ObservedObject var manager = LocationManager()
#FetchRequest(sortDescriptors: [])
private var meals: FetchedResults<Meal>
var body: some View {
Map(coordinateRegion: $manager.region, annotationItems: meals) { meal in // error is on Map
if (meal.latitude != 0 && meal.longitude != 0) {
let coordinate = CLLocationCoordinate2D(latitude: meal.latitude, longitude: meal.longitude)
MapPin(coordinate: coordinate)
}
}
}
}
The LocationManager code is the same, unaltered code from the tutorial and from the demo I wrote. I don't understand why it works in the demo and doesn't work in my app.
I've tried wrapping the code in a Group {} but that didn't fix it. I've read other articles with similar error messages but none of those solutions seemed to apply in this case.
I'm pretty new to Swift and SwiftUI so it makes no sense to me that it should work in the demo but not in my app. I hope I've provided enough information for the problem to make sense.
A couple of things come to mind while looking at your code:
Does Meal conform to Identifiable?
Your closure should always return some sort of map annotation.
Your MapPin(.. ) should work, but it looks like you'll need to filter your array of Meal structs before that closure is called.
The following is untested code, but might help anyway.
extension Meal: Identifiable {
var id: ObjectIdentifier {
return ObjectIdentifier(self)
}
}
extension Meal {
var isValid: Bool {
return latitude != 0 && longitude != 0
}
var coordinate: CLLocationCoordinate2D {
return CLLocationCoordinate2D(latitude: latitude, longitude: longitude)
}
var body: some View {
Map(coordinateRegion:
$manager.region,
annotationItems: meals.filter { $0.isValid ) { meal in
MapPin(coordinate: meal.coordinate)
}
}
I have created a class to perform a network request and parse the data using Combine. I'm not entirely certain the code is correct, but it's working as of now (still learning the basics of Swift and basic networking tasks). My Widget has the correct data and is works until the data becomes nil. Unsure how to check if the data from my first publisher in my SwiftUI View is nil, the data seems to be valid even when there's no games showing.
My SwiftUI View
struct SimpleEntry: TimelineEntry {
let date: Date
public var model: CombineData?
let configuration: ConfigurationIntent
}
struct Some_WidgetEntryView : View {
var entry: Provider.Entry
#Environment(\.widgetFamily) var widgetFamily
var body: some View {
VStack (spacing: 0){
if entry.model?.schedule?.dates.first?.games == nil {
Text("No games Scheduled")
} else {
Text("Game is scheduled")
}
}
}
}
Combine
import Foundation
import WidgetKit
import Combine
// MARK: - Combine Attempt
class CombineData {
var schedule: Schedule?
var live: Live?
private var cancellables = Set<AnyCancellable>()
func fetchSchedule(_ teamID: Int, _ completion: #escaping (Live) -> Void) {
let url = URL(string: "https://statsapi.web.nhl.com/api/v1/schedule?teamId=\(teamID)")!
let publisher = URLSession.shared.dataTaskPublisher(for: url)
.map(\.data)
.decode(type: Schedule.self, decoder: JSONDecoder())
//.catch { _ in Empty<Schedule, Error>() }
//.replaceError(with: Schedule(dates: []))
let publisher2 = publisher
.flatMap {
return self.fetchLiveFeed($0.dates.first?.games.first?.link ?? "")
}
Publishers.Zip(publisher, publisher2)
.receive(on: DispatchQueue.main)
.sink(receiveCompletion: {_ in
}, receiveValue: { schedule, live in
self.schedule = schedule
self.live = live
completion(self.live!)
WidgetCenter.shared.reloadTimelines(ofKind: "NHL_Widget")
}).store(in: &cancellables)
}
func fetchLiveFeed(_ link: String) -> AnyPublisher<Live, Error /*Never if .catch error */> {
let url = URL(string: "https://statsapi.web.nhl.com\(link)")!
return URLSession.shared.dataTaskPublisher(for: url)
.map(\.data)
.decode(type: Live.self, decoder: JSONDecoder())
//.catch { _ in Empty<Live, Never>() }
.eraseToAnyPublisher()
}
}
Like I said in the comments, it's likely that the decode(type: Live.self, decoder: JSONDecoder()) returns an error because the URL that you're fetching from when link is nil doesn't return anything that can be decoded as Live.self.
So you need to handle that case somehow. For example, you can handle this by making the Live variable an optional, and returning nil when link is empty (or nil).
This is just to set you in the right direction - you'll need to work out the exact code yourself.
let publisher2 = publisher1
.flatMap {
self.fetchLiveFeed($0.dates.first?.games.first?.link ?? "")
.map { $0 as Live? } // convert to an optional
.replaceError(with: nil)
}
Then in the sink, handle the nil:
.sink(receiveCompletion: {_ in }, receiveValue:
{ schedule, live in
if let live = live {
// normal treatment
self.schedule = schedule
self.live = live
//.. etc
} else {
// set a placeholder
}
})
SwiftUI and WidgetKit work differently. I needed to fetch data in getTimeline for my IntentTimelineProvider then add a completion handler for my TimelineEntry. Heavily modified my Combine data model. All credit goes to #EmilioPelaez for pointing me in the right direction, answer here.
Hello I want to add ads to a swiftUI grid. The grid contains pictures that I get from a firebase backend and after every couple of pictures I would like to have an ad.
I am quite new to both SwiftUi and working with ads, so I'm not sure how correct my code is, but here is what I got so far.
// Code for the pictures Grid
struct PicturesGrid: View {
private let data: [Item]
var body: some View {
let gridItems = [GridItem(.fixed(UIScreen.screenWidth / 2),
alignment: .leading),
GridItem(.fixed(UIScreen.screenWidth / 2),
alignment: .leading)]
return ScrollView(showsIndicators: false) {
LazyVGrid(columns: gridItems) {
ForEach(0..<self.data.count, id: \.self) { index in
// Using this workaround for the ad to be on the whole width of the screen
// Also, after every six images I am adding and ad
if index != 0, index % 6 == 0 {
AdView()
.frame(width: UIScreen.screenWidth, height: 280)
.padding(.top, 20)
Spacer()
item
.frame(width: UIScreen.screenWidth / 2)
} else {
item
.frame(width: UIScreen.screenWidth / 2)
}
}
}
}
}
// this is for the picture
var item: some View {
NavigationLink(destination: DetailView(viewModel: DetailViewModel(item: itemAtIndexPath))) {
Cell(viewModel: CellViewModel(item: itemAtIndexPath))
}
.buttonStyle(PlainButtonStyle())
}
}
This is the code that I am currently using to load, create and display an ad
// Code for the ad that I am currently using
struct AdView: UIViewControllerRepresentable {
func makeUIViewController(context: Context) -> UIViewController {
let adController = AdViewController(self)
return adController
}
func updateUIViewController(_ uiViewController: UIViewController, context: Context) {}
}
class AdViewController: UIViewController {
private var adView: AdView
/// The height constraint applied to the ad view, where necessary.
var heightConstraint: NSLayoutConstraint?
/// The ad loader. You must keep a strong reference to the GADAdLoader during the ad loading
/// process.
var adLoader: GADAdLoader!
/// The native ad view that is being presented.
var nativeAdView: GADUnifiedNativeAdView!
/// The ad unit ID.
let adUnitID = "ca-app-pub-3940256099942544/3986624511"
init(_ adView: AdView) {
self.adView = adView
super.init(nibName: nil, bundle: nil)
}
required init?(coder: NSCoder) {
fatalError("init(coder:) has not been implemented")
}
override func viewDidLoad() {
super.viewDidLoad()
var nibView: Any?
nibView = Bundle.main.loadNibNamed("ListAdView", owner: nil, options: nil)?.first
guard let nativeAdView = nibView as? GADUnifiedNativeAdView else {
return
}
setAdView(nativeAdView)
adLoader = GADAdLoader(adUnitID: adUnitID, rootViewController: self,
adTypes: [.unifiedNative], options: nil)
adLoader.delegate = self
DispatchQueue.global(qos: .background).async {
self.adLoader.load(GADRequest())
}
}
func setAdView(_ adView: GADUnifiedNativeAdView) {
// Remove the previous ad view.
DispatchQueue.main.async { [weak self] in
guard let weakSelf = self else {
return
}
weakSelf.nativeAdView = adView
weakSelf.view.addSubview(weakSelf.nativeAdView)
weakSelf.nativeAdView.translatesAutoresizingMaskIntoConstraints = false
// Layout constraints for positioning the native ad view to stretch the entire width and height
let viewDictionary = ["_nativeAdView": weakSelf.nativeAdView!]
weakSelf.view.addConstraints(
NSLayoutConstraint.constraints(
withVisualFormat: "H:|[_nativeAdView]|",
options: NSLayoutConstraint.FormatOptions(rawValue: 0), metrics: nil, views: viewDictionary)
)
weakSelf.view.addConstraints(
NSLayoutConstraint.constraints(
withVisualFormat: "V:|[_nativeAdView]|",
options: NSLayoutConstraint.FormatOptions(rawValue: 0), metrics: nil, views: viewDictionary)
)
}
}
}
extension AdViewController: GADUnifiedNativeAdLoaderDelegate {
func adLoader(_ adLoader: GADAdLoader, didFailToReceiveAdWithError error:
GADRequestError) {
print("didFailToReceiveAdWithError: \(error)")
}
func adLoader(_ adLoader: GADAdLoader, didReceive nativeAd: GADUnifiedNativeAd) {
print("Received unified native ad: \(nativeAd)")
// Deactivate the height constraint that was set when the previous video ad loaded.
heightConstraint?.isActive = false
// Populate the native ad view with the native ad assets.
// The headline and mediaContent are guaranteed to be present in every native ad.
(nativeAdView.headlineView as? UILabel)?.text = nativeAd.headline
nativeAdView.mediaView?.mediaContent = nativeAd.mediaContent
// This app uses a fixed width for the GADMediaView and changes its height to match the aspect
// ratio of the media it displays.
if let mediaView = nativeAdView.mediaView, nativeAd.mediaContent.aspectRatio > 0 {
heightConstraint = NSLayoutConstraint(
item: mediaView,
attribute: .height,
relatedBy: .equal,
toItem: mediaView,
attribute: .width,
multiplier: CGFloat(1 / nativeAd.mediaContent.aspectRatio),
constant: 0)
heightConstraint?.isActive = true
}
// This asset is not guaranteed to be present. Check that it is before
// showing or hiding it.
(nativeAdView.advertiserView as? UILabel)?.text = nativeAd.advertiser
nativeAdView.advertiserView?.isHidden = nativeAd.advertiser == nil
// In order for the SDK to process touch events properly, user interaction should be disabled.
nativeAdView.callToActionView?.isUserInteractionEnabled = false
// Associate the native ad view with the native ad object. This is
// required to make the ad clickable.
// Note: this should always be done after populating the ad views.
nativeAdView.nativeAd = nativeAd
}
}
I want to mention that this is working at the moment, but the problems that I want to fix and I don't know how are:
The grid with the pictures load, but when I scroll over an ad, it takes several seconds for the ad to load and display. How could I at least hide it while it loads or make it faster?
If I scroll over an ad, the ad loads and if I continue scrolling, when I scroll back up, the ad is not loaded anymore and I have to wait for it to load again. How can I fix this? Or what is the best practice for this kind of scenario?
Should I use multipleAds? To load them before showing? If yes, then how should I do this?
Does what I am doing here look even a little bit correct? Please...I need some help
The Best Way to show ads in SwiftUI Grids is implementing Native Ads in your app to provide personalized ad experience
When creating a class conforming to ReferenceFileDocument, how do you indicate the document needs saving. i.e. the equivalent of the NSDocument's updateChangeCount method?
I've met the same problem that the SwiftUI ReferenceFileDocument cannot trigger the update. Recently, I've received feedback via the bug report and been suggested to register an undo.
Turns out the update of ReferenceFileDocument can be triggered, just like UIDocument, by registering an undo action. The difference is that the DocumentGroup explicitly implicitly setup the UndoManager via the environment.
For example,
#main
struct RefDocApp: App {
var body: some Scene {
DocumentGroup(newDocument: {
RefDocDocument()
}) { file in
ContentView(document: file.document)
}
}
}
struct ContentView: View {
#Environment(\.undoManager) var undoManager
#ObservedObject var document: RefDocDocument
var body: some View {
TextEditor(text: Binding(get: {
document.text
}, set: {
document.text = $0
undoManager?.registerUndo(withTarget: document, handler: {
print($0, "undo")
})
}))
}
}
I assume at this stage, the FileDocument is actually, on iOS side, a wrapper on top of the UIDocument, the DocumentGroup scene explicitly implicitly assign the undoManager to the environment. Therefore, the update mechanism is the same.
The ReferenceFileDocument is ObservableObject, so you can add any trackable or published property for that purpose. Here is a demo of possible approach.
import UniformTypeIdentifiers
class MyTextDocument: ReferenceFileDocument {
static var readableContentTypes: [UTType] { [UTType.plainText] }
func snapshot(contentType: UTType) throws -> String {
defer {
self.modified = false
}
return self.storage
}
#Published var modified = false
#Published var storage: String = "" {
didSet {
self.modified = true
}
}
}
ReferenceFileDocument exists for fine grained controll over the document. In comparison, a FileDocument has to obey value semantics which makes it very easy for SwiftUI to implement the undo / redo functionality as it only needs to make a copy before each mutation of the document.
As per the documentation of the related DocumentGroup initializers, the undo functionality is not provided automatically. The DocumentGroup will inject an instance of an UndoManger into the environment which we can make use of.
However an undo manager is not the only way to update the state of the document. Per this documentation AppKit and UIKit both have the updateChangeCount method on their native implementation of the UI/NSDocument object. We can reach this method by grabbing the shared document controller on macOS from within the view and finding our document. Unfortunately I don't have a simple solution for the iOS side. There is a private SwiftUI.DocumentHostingController type which holds a reference to our document, but that would require mirroring into the private type to obtain the reference to the native document, which isn't safe.
Here is a full example:
import SwiftUI
import UniformTypeIdentifiers
// DOCUMENT EXAMPLE
extension UTType {
static var exampleText: UTType {
UTType(importedAs: "com.example.plain-text")
}
}
final class MyDocument: ReferenceFileDocument {
// We add `Published` for automatic SwiftUI updates as
// `ReferenceFileDocument` refines `ObservableObject`.
#Published
var number: Int
static var readableContentTypes: [UTType] { [.exampleText] }
init(number: Int = 42) {
self.number = number
}
init(configuration: ReadConfiguration) throws {
guard
let data = configuration.file.regularFileContents,
let string = String(data: data, encoding: .utf8),
let number = Int(string)
else {
throw CocoaError(.fileReadCorruptFile)
}
self.number = number
}
func snapshot(contentType: UTType) throws -> String {
"\(number)"
}
func fileWrapper(
snapshot: String,
configuration: WriteConfiguration
) throws -> FileWrapper {
// For the sake of the example this force unwrapping is considered as safe.
let data = snapshot.data(using: .utf8)!
return FileWrapper(regularFileWithContents: data)
}
}
// APP EXAMPLE FOR MACOS
#main
struct MyApp: App {
var body: some Scene {
DocumentGroup.init(
newDocument: {
MyDocument()
},
editor: { file in
ContentView(document: file.document)
.frame(width: 400, height: 400)
}
)
}
}
struct ContentView: View {
#Environment(\.undoManager)
var _undoManager: UndoManager?
#ObservedObject
var document: MyDocument
var body: some View {
VStack {
Text(String("\(document.number)"))
Button("randomize") {
if let undoManager = _undoManager {
let currentNumber = document.number
undoManager.registerUndo(withTarget: document) { document in
document.number = currentNumber
}
}
document.number = Int.random(in: 0 ... 100)
}
Button("randomize without undo") {
document.number = Int.random(in: 0 ... 100)
// Let the system know that we edited the document, which will
// eventually trigger the auto saving process.
//
// There is no simple way to mimic this on `iOS` or `iPadOS`.
let controller = NSDocumentController.shared
if let document = controller.currentDocument {
// On `iOS / iPadOS` change the argument to `.done`.
document.updateChangeCount(.changeDone)
}
}
}
}
}
Unfortunatelly SwiftUI (v2 at this moment) does not provide a native way to mimic the same functionality, but this workaround is still doable and fairly consice.
Here is a gist where I extended the example with a custom DocumentReader view and a DocumentProxy which can be extended for common document related operations for more convenience: https://gist.github.com/DevAndArtist/eb7e8aa5e7134610c20b1a7aca358604