How can I perform Undo&Redo when the Observable class has a SwiftData Model? 

Question

Created Mar ’24

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I am writing code to be able to perform Undo&Redo with SwiftUI and SwiftData. Unlike usual, there is a Model of SwiftData in the Observable class,

#Preview {
    ContentView()
        .modelContainer(for: Item.self, inMemory: true, isUndoEnabled: true)

@Environment(\.undoManager) var undoManager

but it doesn't work. How should I describe the isUndoEnabled: true option and the undoManager?

import SwiftData

@Observable class SwiftDataCoordinator {
    
    static let shared = SwiftDataCoordinator()

    var items = [Item]()
    
    let modelContainer: ModelContainer = {
        let schema = Schema([
            Item.self
        ])
        
        let modelConfiguration = ModelConfiguration(schema: schema, isStoredInMemoryOnly: false)

        do {
            return try ModelContainer(for: schema, configurations: [modelConfiguration])
        } catch {
            fatalError("Could not create ModelContainer: \(error)")
        }
    }()
}

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Answer 1

DTS Engineer OP

Apple

Jul ’24

It doesn't seem that your code snippet shows how you use undoManager in any way, like calling undo() or redo(), or setting an action name (setActionName(_:))...

So what doesn't work? If you can elaborate how SwiftData undo behaves differently from your expectation with a step by step guide, maybe folks here can better help?

Best,
——
Ziqiao Chen
 Worldwide Developer Relations.

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