FRCDelegate

import UIKit
import CoreData

public class FRCDelegate: NSObject, NSFetchedResultsControllerDelegate {
    
    private unowned let tableView: UITableView
    
    init(tableView: UITableView) {
        self.tableView = tableView
        super.init()
    }
    
    public func controllerWillChangeContent(_ controller: NSFetchedResultsController<NSFetchRequestResult>) {
        self.tableView.beginUpdates()
    }
    
    public func controller(_ controller: NSFetchedResultsController<NSFetchRequestResult>, didChange sectionInfo: NSFetchedResultsSectionInfo, atSectionIndex sectionIndex: Int, for type: NSFetchedResultsChangeType) {
        switch type {
        case .insert:
            self.tableView.insertSections(NSIndexSet(index: sectionIndex) as IndexSet, with: .fade)
        case .delete:
            self.tableView.deleteSections(NSIndexSet(index: sectionIndex) as IndexSet, with: .fade)
        default:
            return
        }
    }
    public func controller(_ controller: NSFetchedResultsController<NSFetchRequestResult>, didChange anObject: Any, at indexPath: IndexPath?, for type: NSFetchedResultsChangeType, newIndexPath: IndexPath?) {
        switch type {
        case .update:
            tableView.reloadRows(at: [indexPath!], with: .fade)
        case .insert:
            tableView.insertRows(at: [newIndexPath!], with: .fade)
        case .delete:
            tableView.deleteRows(at: [indexPath!], with: .fade)
        case .move:
            tableView.deleteRows(at: [indexPath!], with: .fade)
            tableView.insertRows(at: [newIndexPath!], with: .fade)
        }
    }
    
    public func controllerDidChangeContent(_ controller: NSFetchedResultsController<NSFetchRequestResult>) {
        self.tableView.endUpdates()
    }
    
}