What identifier should I add for this optional? - swift

Question

I want to add this optional
var mapRegion : MKCoordinateRegion
It gives me an error that I need an identifier next to class:
class TableViewController: UITableViewController, NSFetchedResultsControllerDelegate,
What's that identifier?
The file looks like this:
import UIKit
import CoreData
import MapKit
class TableViewController: UITableViewController, NSFetchedResultsControllerDelegate, {
let moc = (UIApplication.sharedApplication().delegate as! AppDelegate).managedObjectContext
var frc : NSFetchedResultsController = NSFetchedResultsController()
var mapRegion : MKCoordinateRegion
func fetchRequest() -> NSFetchRequest {
let fetchRequest = NSFetchRequest(entityName: "Item")
let sortDescriptor = NSSortDescriptor(key: "name",
ascending: true)
fetchRequest.sortDescriptors = [sortDescriptor]
return fetchRequest
}
func getFRC() -> NSFetchedResultsController {
frc = NSFetchedResultsController(fetchRequest: fetchRequest(), managedObjectContext: moc, sectionNameKeyPath: nil, cacheName: nil)
return frc
}
override func viewDidLoad() {
super.viewDidLoad()
frc = getFRC()
frc.delegate = self
do {
try frc.performFetch()
} catch {
print("Failed to perform initial fetch.")
return
}
self.tableView.rowHeight = 480
self.tableView.backgroundView = UIImageView( image: UIImage(named: "flatgrey2"))
self .tableView.reloadData()
}
override func viewDidAppear(animated: Bool) {
frc = getFRC()
frc.delegate = self
do {
try frc.performFetch()
} catch {
print("Failed to perform initial fetch.")
return
}
self .tableView.reloadData()
}
override func didReceiveMemoryWarning() {
super.didReceiveMemoryWarning()
// Dispose of any resources that can be recreated.
}
// MARK: - Table view data source
override func numberOfSectionsInTableView(tableView: UITableView) -> Int {
// #warning Incomplete implementation, return the number of sections
let numberOfSections = frc.sections?.count
return numberOfSections!
}
override func tableView(tableView: UITableView, numberOfRowsInSection section: Int) -> Int {
// #warning Incomplete implementation, return the number of rows
let numberofRowsInSection = frc.sections?[section].numberOfObjects
return numberofRowsInSection!
//return 0
}
override func tableView(tableView: UITableView, cellForRowAtIndexPath indexPath: NSIndexPath) -> UITableViewCell {
let cell = tableView.dequeueReusableCellWithIdentifier("cell", forIndexPath: indexPath)
if indexPath.row % 2 == 0 {
cell.backgroundColor = UIColor.clearColor()
} else {
cell.backgroundColor = UIColor.whiteColor().colorWithAlphaComponent(0.2)
cell.textLabel?.backgroundColor = UIColor.whiteColor().colorWithAlphaComponent(0.0)
cell.detailTextLabel?.backgroundColor = UIColor.whiteColor().colorWithAlphaComponent(0.0)
}
// Configure the cell...
cell.textLabel?.textColor = UIColor.darkGrayColor()
cell.detailTextLabel?.textColor = UIColor.darkGrayColor()
let item = frc.objectAtIndexPath(indexPath) as! Item
cell.textLabel?.text = item.name
cell.imageView?.image = UIImage(data: (item.image)!)
return cell
}
/*
// Override to support conditional editing of the table view.
override func tableView(tableView: UITableView, canEditRowAtIndexPath indexPath: NSIndexPath) -> Bool {
// Return false if you do not want the specified item to be editable.
return true
}
*/
// Override to support editing the table view.
override func tableView(tableView: UITableView, commitEditingStyle editingStyle: UITableViewCellEditingStyle, forRowAtIndexPath indexPath: NSIndexPath) {
let managedObject : NSManagedObject = frc.objectAtIndexPath(indexPath) as! NSManagedObject
moc.deleteObject(managedObject)
do {
try moc.save()
} catch {
print ("Failed to save.")
return
}
}
func controller(controller: NSFetchedResultsController, didChangeObject anObject: AnyObject, atIndexPath indexPath: NSIndexPath?, forChangeType type: NSFetchedResultsChangeType, newIndexPath: NSIndexPath?) {
tableView.reloadData()
}
/*
// Override to support rearranging the table view.
override func tableView(tableView: UITableView, moveRowAtIndexPath fromIndexPath: NSIndexPath, toIndexPath: NSIndexPath) {
}
*/
/*
// Override to support conditional rearranging of the table view.
override func tableView(tableView: UITableView, canMoveRowAtIndexPath indexPath: NSIndexPath) -> Bool {
// Return false if you do not want the item to be re-orderable.
return true
}
*/
// MARK: - Navigation
// In a storyboard-based application, you will often want to do a little preparation before navigation
override func prepareForSegue(segue: UIStoryboardSegue, sender: AnyObject?) {
// Get the new view controller using segue.destinationViewController.
// Pass the selected object to the new view controller.
if segue.identifier == "edit" {
let cell = sender as! UITableViewCell
let indexPath = tableView.indexPathForCell(cell)
let itemController : AddEditVC = segue.destinationViewController as! AddEditVC
let item : Item = frc.objectAtIndexPath(indexPath!) as! Item
itemController.item = item
}
}
}

Answer 1

The variable should have a value when it is declared otherwise it will show this error. Assign a value to your variable var mapRegion : MKCoordinateRegion. If the value is given at a later stage i.e., if it depends on any calculations then make it an optional like this var mapRegion : MKCoordinateRegion? But you have to unwrap the variable whenever you want to use mapRegion value by placing an exclamation mark at the end of the variable name.

Answer 2

You have declared var mapRegion : MKCoordinateRegion but don't have any initializers or default value. To make it an optional, just add ? to it, so declare:
var mapRegion : MKCoordinateRegion?