It’s possible to connect to non-BLE devices in iOS with Swift using the External Accessory framework. However, to interact with the device and send/receive data requires detailed knowledge of the manufacturer’s device specifications - which are usually not available. For example, I wanted to connect to a blood pressure monitor via a Swift app, but the device required a sign-in process and the manufacturer refused to provide documentation - probably because their own app collected and stored user data on the company’s server. good luck and regards, Michaela

With your activityManager (CMMotionActivityManager instance in your Data Model) do a query when an app is restarted ref https://developer.apple.com/documentation/coremotion/cmmotionactivitymanager/1615929-queryactivitystarting HOWEVER, only the last 7 days of activity are available - and you'd need to know when the app was terminated or suspended so as not to double count. It might also be possible to schedule a batch background task (e.g. at night) to run the query and place results in permanent data storage. Check out this reference https://developer.apple.com/documentation/backgroundtasks/choosing_background_strategies_for_your_app particularly"Wake Your App with a Background Push". I've never done this, only knowing about it from the documentation. Good luck and regards, Michaela

As of iOS 15 (beta), CreateML can be used within an app to create (or replace) a model within the app, with access to prediction accuracy to determine whether the latest training improves on a previous model.  This requires Xcode 13 (beta) and Mac OS Monterey (beta).  There's also a new TabularData framework that works similarly to CreateML for data input (e.g. from CSV), but appears to have expanded features (not that I've explored them all). CreateML is a set of types and methods for ingesting data, preprocessing those data (e.g. filtering, mapping, transforming), then using the data for training models. Typically, a user would not be aware that these actions are taking place, so it's not, strictly speaking, a UI (i.e there's nothing on-screen). TabularData is an alternative to CreateML's ingestion and preprocessing features, although there are some annoying issues (beta??). I'm trying this out (e.g. time prediction) with a running app that I've developed over the years, and for which I have a lot of historical data. It makes sense to retrain the model after running a new course and also every few weeks as the user improves (or, in my case, degrades). Good luck and regards, Michaela

You can also use Combine, which has various ways of dealing with your scenario - especially if the filtering also needs to be done asynchronously. I use Combine a lot with SwiftUI apps, because Combine’s Publishers can trigger a SwiftUI View’s .onReceive.

I'm not sure if I've understood you correctly (maybe you're after App Store Server information), but here goes: SwiftUI apps typically consist of a number of Views (i.e. the User Interface) and a single Data Model, which handles all of the data processing logic. The Data Model might also interact with a server to store and/or retrieve data. One of my complex apps has servers for SQLite, iCloud, BlueTooth devices and Home Appliances. The Data Model handles all of these servers, consolidating data as required for use by the SwftUI View(s). The Data Model acts as the single point of truth throughout the app: all SwiftUI Views should normally get their UI output from the Data Model and provide UI input (e.g. keyboard input) to the Data Model for processing. SwiftUI monitors for changes to the Data Model, according to developer specified configuration, in order to update the relevant View(s). A simple example of this arrangement is in my answer to this post https://developer.apple.com/forums/thread/685018, which uses Core Motion data to report user activity. The @StateObject var dataModel = DataModel() line in the App View ensures that there's only one copy of dataModel throughout the app, provided conventions for .environmentObject(dataModel) are followed. This Developer document https://developer.apple.com/documentation/swiftui/managing-model-data-in-your-app describes how to manage Model Data. Regards, Michaela

Fixed as of Xcode 13.0 beta 3 (13A5192j) and MacOS 12.0 Beta 21A5284e ( don't know about iOS etc, haven't tried yet). Thank you Engineers. Regards, Michaela

Here's some sample code using a Data Model and SwiftUI **** The Data Model import Foundation import CoreMotion class DataModel : ObservableObject {     var activityManager : CMMotionActivityManager?     @Published var activities = [CMMotionActivity] () // (remove the space before the ()     init() {         if !CMMotionActivityManager.isActivityAvailable() {             print("Activity Monitoring not available")             return         }         activityManager = CMMotionActivityManager()         if activityManager == nil {  // check just to be sure initialised OK             print("Unable to initialise Activity Manager")             return         }         activityManager!.startActivityUpdates(to: OperationQueue.main) { (motion) in             guard let newMotion = motion else { return }             self.activities.append(newMotion)         }     } } extension CMMotionActivity {     func activityString() -> String {         // returns a compound string of activities e.g. Stationary Automotive         var output = ""         if stationary { output = output + "Stationary "}         if walking { output = output + "Walking "}         if running { output = output + "Running "}         if automotive { output = output + "Automotive "}         if cycling { output = output + "Cycling "}         if unknown { output = output + "Unknown "}         return output     } } **** The Main App (if generated in Xcode 12+) import SwiftUI @main struct Activity_TrackerApp: App {     @StateObject var dataModel = DataModel()     var body: some Scene {         WindowGroup {             ContentView()                 .environmentObject(dataModel)         }     } } **** The Content View import SwiftUI struct ContentView: View {     @EnvironmentObject var dataModel: DataModel     var body: some View {         ScrollView {             ForEach(dataModel.activities, id:\.startDate) {activity in                 HStack{                     Text(activity.startDate, style: .date)                     Text(activity.startDate, style: .time)                     Text(activity.activityString())                 }             }         }     } } You must also add a Plist key for Privacy - Motion Usage Description and say why you're recording activity. This is a very rough UI, but it should get you started. You'll also need (??) to turn off monitoring at some point and deal with entering and exiting background mode. Good luck and regards, Michaela

Best to start at this Developer document https://developer.apple.com/documentation/swiftui When I started with SwiftUI, my biggest challenge was in rethinking state and data flow, i.e. creation and manipulation of data, which is now well covered here https://developer.apple.com/documentation/swiftui/state-and-data-flow Although SwiftUI has a lot of inbuilt management of state changes, for complex data models I now use Combine to control what gets published from the data model and when, picking up changes by an onReceive in SwiftUI views. To my mind, the key to SwiftUI is a well designed data model, where all data creation and manipulation is done in the model (using Swift) and SwiftUI only presents data, from a single source of truth data model, to the user. Where the user enters data in SwiftUI, this is handed off to the model, by bindings, for processing. Good luck! Michaela

products is created as an empty array of type ProductModel, I.e. no product (ProductModel) has yet been instantiated. You will need to look at the definition of ProductModel to see what is required for initiation. You can do this in Xcode (jump to Definition), or autocomplete will probably prompt for the required/available parameters.

Ah, fixed it :). All I needed to do was add protocol compliance in an extension for DataFrame.Rows extension DataFrame.Rows : RandomAccessCollection { }. Then use the index property of rows as the id in the SwiftUI ForEach (or List) with yourDataFrame.rows as the source, handling the optionals as required. Cheers, Michaela