I have an app that uses CoreData and I want to migrate to SwiftData. After following the Migrate to SwiftData session, I only need to point to my old Core Data file to read the old data and convert it to the new SwiftData format.
My question is how do I do this? Maybe worth mentioning is that my NSPersistentContainer(name: "Model") is different to my app name.
Possible Solution?
According to a Tweet by Donny Wals this is done this way:
By default a SwiftData ModelContainer will create its underlying storage in a file called default.store. If you want to change this so you can use an existing Core Data SQLite file, you can point your container to that file instead:
// point to your old sqlite file
let url = URL.applicationSupportDirectory.appending(path: "Model.sqlite")
let config = ModelConfiguration(url: url)
modelContainer = try ModelContainer(for: [
Movie.self
], config)
My Tested Code
@main
struct SwiftData_TestApp: App {
let url = URL.applicationSupportDirectory.appending(path: "Model.sqlite")
let config = ModelConfiguration(url: url)
let modelContainer = try ModelContainer(for: [
Item.self
], config)
var body: some Scene {
WindowGroup {
ContentView()
}
.modelContainer(modelContainer)
}
}
The problem here is that I don’t get it to work in the main app struct. When using this the way described in Dive deeper into SwiftData (at 6:58) I only get the error: Cannot use instance member 'url' within property initializer; property initializers run before 'self' is available
PS: There seems to be an issue with this WWDC session method anyway – see this post.
Topic:
App & System Services
SubTopic:
iCloud
Tags:
Core Data
wwdc2023-10189
wwdc2023-10196
SwiftData
2
0
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