NSManagedObjectContext+Project.swift

//
//  NSManagedObjectContext+Project.swift
//
//  Created by Derrick Hathaway on 2/22/15.
//  Copyright (c) 2015 The Best Bits LLC.
//
// Permission is hereby granted, free of charge, to any person
// obtaining a copy of this software and associated documentation
// files (the "Software"), to deal in the Software without
// restriction, including without limitation the rights to use,
// copy, modify, merge, publish, distribute, sublicense, and/or
// sell copies of the Software, and to permit persons to whom the
// Software is furnished to do so, subject to the following
// conditions:

// The above copyright notice and this permission notice shall be
// included in all copies or substantial portions of the Software.

// THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
// EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES
// OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
// NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT
// HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY,
// WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
// FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR
// OTHER DEALINGS IN THE SOFTWARE.

import CoreData

private struct Singleton {
    static var psc: NSPersistentStoreCoordinator!
    static var main: NSManagedObjectContext!
}

private var once: dispatch_once_t = 0
private func prep() {
    dispatch_once(&once) {
        let bundle = NSBundle(forClass: OneOfYourModelClasses.classForCoder())
        let modelURL = bundle.URLForResource(XCDataModelFileName, withExtension: "momd")!
        let model = NSManagedObjectModel(contentsOfURL: modelURL)
        
        Singleton.psc = NSPersistentStoreCoordinator(managedObjectModel: model!)
        let libURL = NSFileManager.defaultManager().URLsForDirectory(NSSearchPathDirectory.LibraryDirectory, inDomains: NSSearchPathDomainMask.UserDomainMask)[0] as NSURL
        let storeURL = libURL.URLByAppendingPathComponent(file_name.sqlite)
        var error: NSError?
        Singleton.psc.addPersistentStoreWithType(NSSQLiteStoreType, configuration: nil, URL: storeURL, options: nil, error: &error)
        
        Singleton.main = NSManagedObjectContext(concurrencyType: .MainQueueConcurrencyType)
        Singleton.main.persistentStoreCoordinator = Singleton.psc
    }
}

public extension NSManagedObjectContext {
    public class var main: NSManagedObjectContext {
        prep()
        return Singleton.main
    }
}

public typealias MOC = NSManagedObjectContext


public extension String {
    public var ascending: NSSortDescriptor {
        return NSSortDescriptor(key: self, ascending: true)
    }
    public var descending: NSSortDescriptor {
        return NSSortDescriptor(key: self, ascending: false)
    }
}