How can I cast a NSManagedObject to NSItemProviderWriting/NSItemProviderReading?

Question

I wanna implement the function that drag a tableview cell on a "Delete Icon" to delete it.

Now my question is how can I cast my Type to NSItemProviderWriting/NSItemProviderReading to use drag and drop.

I'm following this tutorial: https://exploringswift.com/blog/creating-a-nsitemprovider-for-custom-model-class-drag-drop-api . While I failed and I still could not understand how it works.

It says that Type 'Task' does not conform to protocol 'Decodable'.('Task' is my custom model) and I also don't know what 'kUTTypeData' is in this tutorial...

Can anyone help to how to implement these protocol?

import Foundation
import CoreData

@objc(Task)
public class Task: NSManagedObject, NSItemProviderWriting, NSItemProviderReading, Codable {

    public override init(entity: NSEntityDescription, insertInto context: NSManagedObjectContext?) {
        <#code#>
    }

    required public init(from decoder:Decoder) throws {
        let values = try decoder.container(keyedBy: CodingKeys.self)
    }

    public static var writableTypeIdentifiersForItemProvider: [String] {
        return []
    }

    public func loadData(withTypeIdentifier typeIdentifier: String, forItemProviderCompletionHandler completionHandler: @escaping (Data?, Error?) -> Void) -> Progress? {

        let progress = Progress(totalUnitCount: 100)

        do {
            let encoder = JSONEncoder()
            let data = try encoder.encode(self)
            progress.completedUnitCount = 100
            completionHandler(data, nil)
        } catch {
            completionHandler(nil, error)
        }

        return progress
    }

    public static var readableTypeIdentifiersForItemProvider: [String] {
        return []
    }

    public static func object(withItemProviderData data: Data, typeIdentifier: String) throws -> Self {

        let decoder = JSONDecoder()

        do {
            let myJSON = try decoder.decode(Task.self, from: data)
            return myJSON as! Self
        } catch {
            fatalError("Err")
        }
    }


}

Answer 1

Instead of making the NSManagedObject conform to the protocols, have you considered using .objectID.uriRepresentation() in the drag/drop handlers?

Answer 2

Here you can find an explanation for implementing Codable with Core Data entities: https://stackoverflow.com/a/46917019