CoreData relationships

CoreDataDAORelationshipsExample.swift

// сущность Core Data
// CDEntry: NSManagedObject
class CDFolder: CDEntry {
    @NSManaged var name: String?
    @NSManaged var messages: [CDMessage]?

    //...
}


class FolderCoreDataTranslator: CoreDataTranslator<CDFolder, Folder> {
    
    override func toEntity(_ entry: CDFolder) -> Folder {
        let messages = MessageCoreDataTranslator().toEntities(entry.messages)
        
        return Folder(entityId: entry.entryId, name: entry.name, messages: messages)
    }
    

    //context нужен для создания сущностей
    override func toEntry(_ entity: Folder, context: NSManagedObjectContext) -> CDFolder {
        let entityDescription = NSEntityDescription.entity(forEntityName: "CDFolder", in: context)!
        let dbFolder = CDFolder(entity: entityDescription, insertInto: context)
        
        dbFolder.entryId = entity.entityId
        dbFolder.name = entity.name        
        dbFolder.messages = MessageCoreDataTranslator().toEntries(entity.messages, context: context)
        
        return dbFolder
    }
}