You already did what most people would suggest first, make sure the project format is set to a version that will open in an older version of Xcode. That is going to make finding a solution tougher so you have to provide more details for anyone to help you. List the steps you took to create the project in Xcode 15, and be specific and detailed. What type of project did you create?

Your project idea sounds overwhelming for a first project. I recommend starting with a simpler project before attempting this project. If you really want to do this project right now, start with one smaller part, such as editing HTML, and moving on to things like WYSIWYG editing, video, audio, and sharing documents with users later. Some technologies you need to learn to make this app include the following: SwiftUI for the user interface because you want the app to run on iOS and Mac. PDFKit for showing PDF files. TextKit, and the NSTextView and UITextView classes. SwiftUI's text editor is very limited and does not support WYSIWYG editing. You would have to subclass NSTextView and UITextView to do WYSIWYG editing. You might need to study AVFoundation for the video and audio files. You might find the following list of frameworks for text editing helpful: https://github.com/mattmassicotte/TextEditingReference

Why do you need to use the macOS 10.14 SDK? If you want your app to run on macOS 10.14, set the deployment target for your app to 10.14, and you can use the macOS 14 SDK that ships with Xcode 15. By setting the deployment target to 10.14, your app will run on macOS 10.14 and above, assuming you aren't using any new technologies Apple added in later OS versions. Read the following article if you don't know how to change the deployment target. https://www.swiftdevjournal.com/supporting-older-versions-of-ios-and-macos/

The answers to the following Stack Overflow question may help you: https://stackoverflow.com/questions/65209295/how-do-i-hide-default-commandmenu-in-swiftui-on-macos/70553784#70553784

You can use any backend you want in an iOS app, including a Python backend. I haven't used a Python backend in an iOS app so I can't provide more details on how to do it.

I have not tried loading a SpriteKit scene from a .sks file to a SwiftUI sprite view so I don't have a specific solution for you. I have some tips and suggestions that may help you solve the problem yourself or give other people here enough information to help you. It works with some changes Show the code you use to declare the property for the scene in the SwiftUI view. I still can't interact with the MapScene Provide more details. What are you trying to do? What do you expect to happen? What happens? Set a breakpoint in your touchesBegan or mouseDown functions. If you run your project and tap or click in the scene, does the breakpoint fire? If you have not used Xcode's debugger before, read the following article: https://www.swiftdevjournal.com/an-introduction-to-xcodes-debugger/ I doubt you are the first person to have trouble loading a SpriteKit scene into a SwiftUI view. Search on Stack Overflow or a search engine, and chances are high someone has had the same problem and received a solution.

I found a mention of MACOSX_DEPLOYMENT_TARGET in Xcode's Build Setting Reference. https://developer.apple.com/library/archive/documentation/DeveloperTools/Reference/XcodeBuildSettingRef/1-Build_Setting_Reference/build_setting_ref.html#//apple_ref/doc/uid/TP40003931-CH3-SW129 I created a new Mac app project in Xcode 14.2, and the project has a setting for the macOS deployment target, so I think the MACOSX_DEPLOYMENT_TARGET build setting is still used.

What is golfDBdata? I don't see it declared in the code you showed. I assume it's an array. How many elements does it have? What is numDB? What is its value? The error message is telling you that the value of numDB is greater than or equal to the number of elements in golfDBdata. Another potential problem you have is you are running the code asynchronously. You may be trying to access data before it's been fetched.

It shows a black screen because you passed an empty scene to the sprite view. SpriteView(scene:MapScene()) Calling MapScene() creates an empty scene. You must add a property to your view that holds the scene to show in the sprite view. Call newGameScene to initialize it. @State var mapScene = MapScene.newGameScene() I haven't tested that line of code so you may have to make some changes to get it to work. But it gives you an idea of what you need to do. Pass that property to the sprite view. SpriteView(scene: mapScene)

Create a subclass of SKScene for your SpriteKit scene and use that class to write the code to interact with the scene. Interact with the scene by overriding the touch functions on iOS and the mouse functions on Mac. On iOS you must override touchesBegan. You may also need to override touchesMoved and touchesEnded. On Mac you must override mouseDown. You may also need to override mouseDragged and mouseUp.

Your decks property is an array of type Deck, not a single deck. An array of Deck does not have a name, therefore the following line of code won't work: Text(decks.name) You need to show the name of a single deck in the Text label. If you want to show the names of all the decks, create a list and have a Text label for each item in the list. List(decks) { deck in Text(deck.name) }

Read Jonathan's answer to the following Stack Overflow question: https://stackoverflow.com/questions/76412754/how-to-run-on-ios-17-device-using-xcode-14

The Value column may be hidden because the Key column is so wide. Can you see the Value column if you drag the splitter (the thin line next to Type in your screenshot) to the left? You should be able to change the values from the Value column.

You have posted a lot of code, but there is one important piece of code missing. Your HistoryView has the following property that contains the history data: @StateObject var historyData1 = historyData() Your InvoiceView has the following property: @ObservedObject var historyData: historyData But I do not see any code on how you set the InvoiceView's historyData value. Is the value of historyData supposed to be the same as HistoryView's historyData1 property? I think you have a better chance of getting an answer if you post a new question and strip out most of the code. The problem you have is the list isn't updating when you add a new item to it. Show the code that deals with adding the items to the list and strip out the other stuff. You have posted so much code that has nothing to do with the problem, and that makes it hard for people reading the question to see the code they need to answer your question. I also recommend coming up with better names for some of your data structures and variables. You have a struct named HistoryData and a class named historyData. That is confusing because the only difference in the names is making the H in History uppercase or lowercase. You have a variable named historyData and another one named historyData1. I know it can be hard to come up with good variable names, but your code will be easier for people to read if you give your data structures and variables less confusing names.

Show the code for the view where you add the new item and the code that adds the new item. Without that code people can only guess as to why the list is not updating when you add a new item.