A sort of generic FetchedResultsController delegate.

GenericTableFetchResultsControllerDelegate.swift

import UIKit
import CoreData

class GenericTableFetchResultsController: NSObject {
    
    fileprivate var tableView: UITableView!
    fileprivate var rowAnimation: UITableViewRowAnimation!
    
    init(tableView: UITableView, rowAnimation: UITableViewRowAnimation) {
        self.tableView = tableView
        self.rowAnimation = rowAnimation
    }
}

extension GenericTableFetchResultsController: NSFetchedResultsControllerDelegate {

    func controller(_ controller: NSFetchedResultsController<NSFetchRequestResult>, didChange anObject: Any, at indexPath: IndexPath?, for type: NSFetchedResultsChangeType, newIndexPath: IndexPath?) {
        
        switch type {
            
        case .insert:
            
            DispatchQueue.main.async {
                guard let path = newIndexPath else {
                    assertionFailure("CoreData Issue: newIndexPath should be here on insert.")
                    return
                }
                
                self.tableView.insertRows(at: [path], with: self.rowAnimation)
            }
            
        case .update:
            DispatchQueue.main.async {
                guard let path = indexPath else {
                    assertionFailure("CoreData Issue: indexPath should be here on update.")
                    return
                }
                
                self.tableView.reloadRows(at: [path], with: self.rowAnimation)
            }
            
        case .move:
            DispatchQueue.main.async {
                guard let oldPath = indexPath, let newPath = newIndexPath else {
                    assertionFailure("CoreData Issue: Both indexPaths are required for a move.")
                    return
                }
                
                self.tableView.moveRow(at: oldPath, to: newPath)
            }
            
        case .delete:
            DispatchQueue.main.async {
                guard let path = indexPath else {
                    assertionFailure("CoreData Issue: indexPath should be here on delete.")
                    return
                }
                
                self.tableView.deleteRows(at: [path], with: self.rowAnimation)
            }
        }
    }

    func controller(_ controller: NSFetchedResultsController<NSFetchRequestResult>, didChange sectionInfo: NSFetchedResultsSectionInfo, atSectionIndex sectionIndex: Int, for type: NSFetchedResultsChangeType) {
        
        switch type {
        case .insert:
            DispatchQueue.main.async {
                self.tableView.insertSections(IndexSet(integer: sectionIndex), with: self.rowAnimation)
            }
            
        case .update:
            DispatchQueue.main.async {
                self.tableView.reloadSections(IndexSet(integer: sectionIndex), with: self.rowAnimation)
            }
            
        case .delete:
            DispatchQueue.main.async {
                self.tableView.deleteSections(IndexSet(integer: sectionIndex), with: self.rowAnimation)
            }
            
        default: break
            
        }
    }
    
    func controllerWillChangeContent(_ controller: NSFetchedResultsController<NSFetchRequestResult>) {
        DispatchQueue.main.async {
            self.tableView.beginUpdates()
        }
    }
    
    func controllerDidChangeContent(_ controller: NSFetchedResultsController<NSFetchRequestResult>) {
        DispatchQueue.main.async {
            self.tableView.endUpdates()
        }
    }
}