Create Nsmanagedobject Subclass... Make a New Error in My Project

Create NSManagedObject Subclass... make a new Error in my project

Select the xcdatamodeld file in the project navigator, select the entity and press ⌥⌘3 – in Xcode 13 ⌥⌘4 – to show the Data Model Inspector.

If you created the class manually the Codegen popup must be set to Manual/None otherwise the class file is created implicitly.

Errors after 'Create NSManagedObject Subclass for CoreData Entities

The current default in Xcode is to automatically create subclasses of NSManagedObject for you in the /Users/<your user name>/Library/Developer/Xcode/DerivedData/AppName-agkwmibzbo‌​pevjgfajlcbyixzyev/B‌​uild/Intermediates/A‌​ppName.build/Debug-i‌​phonesimulator/AppNa‌​me.build/DerivedSour‌​ces/CoreDataGenerate‌​d/Modeldirectory; The DerivedData directory is where Xcode saves automatically generated code. You are redeclaring the same subclass by doing Editor>Create NSManagedObject Subclass... that is why you are getting the "Invalid redeclaration of 'UserRoutine' 'UserExercise' is ambiguous for type lookup in this context @NSManaged only allowed on an instance property or method" error. To resolve the errors and manually create a subclass of NSManagedObjects what you need to do is:

1. Open terminal and navigate to /Users/<your user name>/Library/Developer/Xcode/DerivedData/AppName-agkwmibzbo‌​pevjgfajlcbyixzyev/B‌​uild/Intermediates/A‌​ppName.build/Debug-i‌​phonesimulator/AppNa‌​me.build/DerivedSour‌​ces/CoreDataGenerate‌​d/Model

2. Run this command: rm -rf * (now be careful with this command, run it only when you get to the final directory where the generated codes are or you'll break your project for good)

3. Delete your current data model

4. Create a new data model

5. Select your new data model's entity (do this for each entity within the data model) and go to its attributes inspector and set its Codegen to Manual/None Before the first run after you have created a new data model.

6. Create a subclass of NSManagedObject by going to Editor>Create NSManagedObject Subclass...

Your errors should disappear.

Hope this helped!

Cannot create NSManagedObject subclass

You are manually generating a NSManagedObject subclass, which has already been generated by Xcode.

Find detailed solutions here.

Xcode 8 generates broken NSManagedObject subclasses for iOS 10

I finally got mine to work. Here is what I did. (Flights is one of my entities)

I setup the xcdatamodeld as follows

And then the entity as

Then I used Editor -> Create NSManagedObject Subclass

This creates two files for my flights entity

Flights+CoreDataProperties.swift

Flights+CoreDataClass.swift

I renamed Flights+CoreDataClass.swift to Flights.swift

Flights.swift is just

import Foundation
import CoreData

@objc(Flights)
public class Flights: NSManagedObject {

}

Flights+CoreDataProperties.swift is

import Foundation
import CoreData


extension Flights {

    @nonobjc public class func fetchRequest() -> NSFetchRequest<Flights> {
        return NSFetchRequest<Flights>(entityName: "Flights");
    }

    @NSManaged public var ...
}

This appears to work for me.I could not get Codegen to work in any other way, even though I tried many of the suggestions that were out there.

Also this had me scratching my head for a while and I add it as an assist. Don't forget with the new Generics version of the FetchRequest you can do this

let fetchRequest: NSFetchRequest<NSFetchRequestResult> = NSFetchRequest(entityName: "Flights")

Duplicate Symbol Error in NSManagedObject Subclass

You are generating files which have already been generated for you by Xcode and thus get duplicate declarations. Details about this feature (new in Xcode 8) can be found in this WWDC video.

Two possible fixes:

1) Use the Xcode generated ManagedObject subclasses (the recommended, modern approach)

• Delete all generated NSManagedObject subclasses from your project, if exists.
• Set Codegento Class Definition in your .xcdatamodel for all entities
• Make sure Module is empty ("Global Namespace" in light gray) (workaround an Apple bug, see this answer)

• Clean project
• Clean DerivedData folder (Optional. To be on the save side)
• build

Note:

Never add the automatically generated files to your project. Even you do not see the generated files in your project, Xcode has a reference to it, so you are able to write extensions and such. For instance:

extension MyEntity {
    func doSomething() {
        //
    }
}

Also, you can command+click to the generated file within Xcode.

2) Trigger subclass generation manually (a rather paranoid but bullet-prove approach, ignoring the new Xcode features)

• Delete all generated NSManagedObject subclasses from your project, if exists.
• Set Codegento Manual/None in your .xcdatamodel for all entities
• Clean project
• Clean DerivedData folder
• Restart Xcode
• Manually generate NSManagedObject subclasses (in "Editor" menu)
• Make sure those files are added to your project
• build

Xcode generate NSManagedObject Subclass issue

So I also ran in this issue. You have to disable automatical code generation if you want to create the NSManagedObjects by yourself. So there are different ways. First way is go to your model and changed the Toolversion to xCode 7.3.
In every entity you can set the Codegen to Manual/None like in the Screenshot.
Clean your project, and try again!
I hope this was helpful.

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