ManagedModels

Adds and enables strict concurrency checks on Xcode 15.3/Swift 5.10. Thanks to @radianttap!

ManagedModels for CoreData

Instead of wrapping CoreData, use it directly :-)

The key thing ManagedModels provides is a @Model macro, that works similar (but not identical) to the SwiftData @Model macro. It generates an NSManagedObjectModel straight from the code. I.e. no CoreData modeler / data model file is necessary.

A small sample model:

@Model class Item: NSManagedObject {
  var timestamp : Date
  var title     : String?
}

The full CoreData template application converted to ManagedModels

import SwiftUI
import ManagedModels

@Model class Item: NSManagedObject {
  var timestamp : Date
}

struct ContentView: View {

  @Environment(\.modelContext) private var viewContext
  
  @FetchRequest(sort: \.timestamp, animation: .default)
  private var items: FetchedResults<Item>
  
  var body: some View {
    NavigationView {
      List {
        ForEach(items) { item in
          NavigationLink {
            Text("Item at \(item.timestamp!, format: .dateTime)")
          } label: {
            Text("\(item.timestamp!, format: .dateTime)")
          }
        }
        .onDelete(perform: deleteItems)
      }
      .toolbar {
        ToolbarItem(placement: .navigationBarTrailing) {
          EditButton()
        }
        ToolbarItem {
          Button(action: addItem) {
            Label("Add Item", systemImage: "plus")
          }
        }
      }
      Text("Select an item")
    }
  }
  
  private func addItem() {
    withAnimation {
      let newItem = Item(context: viewContext)
      newItem.timestamp = Date()
      try! viewContext.save()
    }
  }
  
  private func deleteItems(offsets: IndexSet) {
    withAnimation {
      offsets.map { items[$0] }.forEach(viewContext.delete)
      try! viewContext.save()
    }
  }
}

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

This is not intended as a replacement implementation of SwiftData. I.e. the API is kept similar to SwiftData, but not exactly the same. It doesn't try to hide CoreData, but rather provides utilities to work with CoreData in a similar way to SwiftData.

A full To-Do list application example: ManagedToDos.app.

Blog article describing the thing: @Model for CoreData.

Requirements

The macro implementation requires Xcode 15/Swift 5.9 for compilation. The generated code itself though should backport way back to iOS 10 / macOS 10.12 though (when NSPersistentContainer was introduced).

Package URL:

https://github.com/Data-swift/ManagedModels.git

ManagedModels has no other dependencies.

Differences to SwiftData

The model class must explicitly inherit from NSManagedObject (superclasses can't be added by macros), e.g. @Model class Person: NSManagedObject.
Uses the CoreData @FetchRequest property wrapper instead @Query.
Doesn't use the new Observation framework (which requires iOS 17+), but uses ObservableObject (which is directly supported by CoreData).

TODO

Pull requests are very welcome! Even just DocC documentation or more tests would be welcome contributions.

Disclaimer

SwiftData and SwiftUI are trademarks owned by Apple Inc. Software maintained as a part of the this project is not affiliated with Apple Inc.

Who

ManagedModels are brought to you by Helge Heß / ZeeZide. We like feedback, GitHub stars, cool contract work, presumably any form of praise you can think of.

0.8.6

What's New

Strictly Concurrent

2024-03-24T12:45:07Z

ManagedModels for CoreData

Requirements

Differences to SwiftData

TODO

Links

Disclaimer

Who

Description

Dependencies