I am working on a SwiftData document-based app. Most things were progressing pretty well until I tried to build more complicated predicates; specifically the lack of NSCompoundPredicate-like support in SwiftData. I have been trying to incorporate Core Data to coexists in my app so I can use FetchRequest when I need complicated predicates. There isn't a lot of information available. I have looked at Apple documentations, WWDC videos, HackingWithSwift, SO, etc.

If you know how I can get a NSManagedObjectContext from the SwiftData document modelContext in my app, please advice.

My simplified App code is below:

  @main
struct MyApp: App {

  var body: some Scene {
      DocumentGroup(editing: .myAppDocument, migrationPlan: MyAppMigrationPlan.self) {
          MainWindowView()
      }
  }
}

extension UTType {
  static var myAppDocument: UTType {
      UTType(importedAs: "com.example.myApp")
  }
}

struct MYAppMigrationPlan: SchemaMigrationPlan {
  static var schemas: [VersionedSchema.Type] = [
      MYAppVersionedSchema.self,
  ]

  static var stages: [MigrationStage] = [
      // Stages of migration between VersionedSchema, if required.
  ]
}

struct MyAppVersionedSchema: VersionedSchema {
  static var versionIdentifier = Schema.Version(1, 0, 0)

  static var models: [any PersistentModel.Type] = [
      Entry.self, Tag.self, Collection.self
  ]
}

So I would like to get a NSManagedObjectContext with the same persistent container as the SwiftData document. I think the place to do it is in MainWindowView(). But I am at a lost on how to make it happen. I have tried looking into view global environment objects like documentConfiguration, modelContext, and managedObjectContext but failed to make the managedObjectContext share the same container as modelContext.

Any info/hint is greatly appreciated. Thank you for reading.