Deleting all nested data

Question

I have four models: Subject > Topic > Content > Block.

• When deleting a Subject I also want to delete the nested Topic, Content and Block.

• When deleting a Topic I want to delete the nested Content and Block.

• When deleting a Content I want to delete the nested Block.

How should I do that?

Answer 1

I tried to put this in the comments, but its too small to see. I don't recommend forcing CoreData I think the problem may be somewhere else and I would definitely give it some thought. But in a pinch you can just delete the references.

I think this code is right:

        func delete(_ item: NSManagedObject) {
        let context = item.managedObjectContext!
        
        switch item.entity.name {
            case .some("Subject"):
                (item as! Subject).topic.forEach({delete($0)})

            case .some("Topic"):
                (item as! Topic).content.forEach({delete($0)})

            case .some("Content"):
                (item as! Content).block.forEach({delete($0)})

            default:
                break
        }
       
        context.delete(item)
    }

I don't have a quick way to test right now. But something recursive like this would probably be your best bet.