ObjectObserver.swift

//
//  ObjectObserver.swift
//
//  Created by Garo Hussenjian on 2/21/16.
//

import Foundation
import CoreData

struct ObjectObserver<T: NSManagedObject> {

    // The fetch request should yield 0 or 1 fetched object
    let fetchRequest: NSFetchRequest

    let context: NSManagedObjectContext

    let fetchedResultsController: NSFetchedResultsController
    
    var object: T? {
        return fetchedResultsController.fetchedObjects?.first as? T
    }

    init(fetchRequest: NSFetchRequest, context: NSManagedObjectContext) {
        self.fetchRequest = fetchRequest
        self.context = context
        fetchedResultsController = NSFetchedResultsController(fetchRequest: fetchRequest, managedObjectContext: context, sectionNameKeyPath: nil, cacheName: nil)
        try! fetchedResultsController.performFetch()
    }

}