CoreDataStack for iOS 9 and 10. Supporting Swift 3.0

CoreDataStack.swift

//
//  CoreDataStack.swift
//  Jose
//
//  Created by JOSE ANTONIO MARTINEZ FERNANDEZ on 31/10/2016.
//  Copyright © 2016 joamafer. All rights reserved.
//

import UIKit
import CoreData

extension NSPersistentStoreCoordinator {
    
    public enum CoordinatorError: Error {
        case modelFileNotFound, modelCreationError, storePathNotFound
    }
    
    static func coordinator(name: String) throws -> NSPersistentStoreCoordinator? {
        
        guard let modelURL = Bundle.main.url(forResource: name, withExtension: "momd") else {
            throw CoordinatorError.modelFileNotFound
        }
        
        guard let model = NSManagedObjectModel(contentsOf: modelURL) else {
            throw CoordinatorError.modelCreationError
        }
        
        let coordinator = NSPersistentStoreCoordinator(managedObjectModel: model)
        
        guard let documents = FileManager.default.urls(for: .documentDirectory, in: .userDomainMask).last else {
            throw CoordinatorError.storePathNotFound
        }
        
        do {
            let url = documents.appendingPathComponent("\(name).sqlite")
            let options = [ NSMigratePersistentStoresAutomaticallyOption : true,
                            NSInferMappingModelAutomaticallyOption : true ]
            try coordinator.addPersistentStore(ofType: NSSQLiteStoreType, configurationName: nil, at: url, options: options)
        } catch {
            throw error
        }
        
        return coordinator
    }
}

struct CoreDataStack {
    
    static var shared = CoreDataStack()
    static let modelName = "CoreDataStack"
    
    @available(iOS 10.0, *)
    private lazy var persistentContainer: NSPersistentContainer = {
        let container = NSPersistentContainer(name: modelName)
        container.loadPersistentStores { (storeDescription, error) in
            guard error == nil else {
                print("CoreData: Unresolved error \(error)")
                return
            }
        }
        return container
    }()
    
    private lazy var persistentStoreCoordinator: NSPersistentStoreCoordinator? = {
        do {
            return try NSPersistentStoreCoordinator.coordinator(name: modelName)
        } catch {
            print("CoreData: Unresolved error \(error)")
        }
        return nil
    }()
    
    private lazy var managedObjectContext: NSManagedObjectContext = {
        let coordinator = self.persistentStoreCoordinator
        var managedObjectContext = NSManagedObjectContext(concurrencyType: .mainQueueConcurrencyType)
        managedObjectContext.persistentStoreCoordinator = coordinator
        return managedObjectContext
    }()
    
    // MARK: Public methods
    
    enum SaveStatus {
        case saved, rolledBack, hasNoChanges
    }
    
    var context: NSManagedObjectContext {
        mutating get {
            if #available(iOS 10.0, *) {
                return persistentContainer.viewContext
            } else {
                return managedObjectContext
            }
        }
    }
    
    mutating func save() -> SaveStatus {
        if context.hasChanges {
            do {
                try context.save()
                return .saved
            } catch {
                context.rollback()
                return .rolledBack
            }
        }
        return .hasNoChanges
    }
}

hi, how to access app group container with core data stack for ios 10... with
static let applicationGroupIdentifier = "com.fetchDatainExtension"
if let newURL =
FileManager.default.containerURL(
forSecurityApplicationGroupIdentifier: "group.com.fetchDatainExtension.contacts") {
url = newURL
}