Data not being passed through Segue - ios

Question

I have a slightly confusing issue, I am trying to send location data from a tableview through to a mapkit. My tableview loads the various bits of info to list the names of the location, when I click a cell it segues into a navigation view with the data, however it doesnt seem to be sending the data and errors with found nil issue. I did have this same tableview segueing to a different controller and it worked without issue.
This is my prepareForSegue on my main Viewcontroller
override func prepare(for segue: UIStoryboardSegue, sender: Any?) {
if segue.identifier == "mapLocation" {
if let detailsVC = segue.destination as? mapLocation {
if let tr = sender as? newTracks {
detailsVC.track = tr
}
}
}
}
This is the mapkit view to segue to
import UIKit
import MapKit
import CoreLocation
class mapLocation: UIViewController, MKMapViewDelegate {
#IBOutlet weak var mapView: MKMapView!
var track: newTracks!
override func viewDidLoad() {
super.viewDidLoad()
let sourceloaction = CLLocationCoordinate2D(latitude: track.lat, longitude: track.lon)
let destinationLocation = CLLocationCoordinate2D(latitude: track.lat, longitude: track.lon)
let sourcePlacemark = MKPlacemark(coordinate: sourceloaction, addressDictionary: nil)
let destinationPlacemark = MKPlacemark(coordinate: destinationLocation, addressDictionary: nil)
let sourceMapItem = MKMapItem(placemark: sourcePlacemark)
let destinationMapItem = MKMapItem(placemark: destinationPlacemark)
let sourceAnnotation = MKPointAnnotation()
sourceAnnotation.title = track.name
if let location = sourcePlacemark.location {
sourceAnnotation.coordinate = location.coordinate
}
let destinationAnnotation = MKPointAnnotation()
destinationAnnotation.title = track.name
if let location = destinationPlacemark.location {
destinationAnnotation.coordinate = location.coordinate
}
self.mapView.showAnnotations([sourceAnnotation,destinationAnnotation], animated: true)
let directionRequest = MKDirectionsRequest()
directionRequest.source = sourceMapItem
directionRequest.destination = destinationMapItem
directionRequest.transportType = .automobile
let directions = MKDirections(request: directionRequest)
directions.calculate {
(response, error) -> Void in
guard let response = response else {
if let error = error {
print("Error: \(error)")
}
return
}
let route = response.routes[0]
self.mapView.add((route.polyline), level: MKOverlayLevel.aboveRoads)
let rect = route.polyline.boundingMapRect
self.mapView.setRegion(MKCoordinateRegionForMapRect(rect), animated: true)
}
}
func mapView(_ mapView: MKMapView, rendererFor overlay: MKOverlay) -> MKOverlayRenderer {
let renderer = MKPolylineRenderer(overlay: overlay)
renderer.strokeColor = UIColor.red
renderer.lineWidth = 4.0
return renderer
}
}
and this is my NewTracks struct where the data is loaded to/from:
import Foundation
import FirebaseDatabase
struct newTracks {
let name: String!
let trackId: Int!
let postcode: String!
let trackType: String!
let locID: Int!
let lat: Double!
let lon: Double!
let phoneNumber: String!
let email: String!
let rating: Double!
let numrating: Double!
let totalrating: Double!
let ref: FIRDatabaseReference?
init(name: String, trackId: Int, postcode: String, trackType: String, trackURL: String, locID: Int, lat: Double, lon: Double, phoneNumber: String, email: String, rating: Double, numrating: Double, totalrating: Double) {
self.name = name
self.trackId = trackId
self.ref = nil
self.postcode = postcode
self.trackType = trackType
self.locID = locID
self.lat = lat
self.lon = lon
self.phoneNumber = phoneNumber
self.email = email
self.rating = rating
self.numrating = numrating
self.totalrating = totalrating
}
init(snapshot: FIRDataSnapshot) {
let snapshotValue = snapshot.value as! [String: AnyObject]
name = snapshotValue["name"] as! String
trackId = snapshotValue["id"]as! Int
postcode = snapshotValue["postcode"]as! String
trackType = snapshotValue["type"]as! String
locID = snapshotValue["locID"]as! Int
lat = snapshotValue["lat"]as! Double
lon = snapshotValue["long"]as! Double
phoneNumber = snapshotValue["phone"]as! String
email = snapshotValue["email"]as! String
rating = snapshotValue["rating"]as! Double
ref = snapshot.ref
numrating = snapshotValue["numrating"] as! Double
totalrating = snapshotValue["totalrating"] as! Double
}
func toAnyObject() -> Any {
return [
"name": name,
"trackId": trackId,
"postcode": postcode,
"trackType": trackType,
"locID": locID,
"lat": lat,
"lon": lon,
"phoneNumber": phoneNumber,
"email": email,
"rating": rating,
"numrating": numrating,
"totalrating": totalrating
]
}
}
The error happens on the line in the mapLocation VC
let sourceloaction = CLLocationCoordinate2D(latitude: track.lat, longitude: track.lon)
the lat and lon values are not being passed for some reason.
On my previous VC that the segue worked fine with the data all I had to do was to add the
var track: newTracks
and this allowed the communication to happen back to where the data is coming from, but for some reason it doesn't appear to be working now. I know it will be something fundamentally simple I have missed.
This is my original segue code that worked to a normal View COntroller, not a UINavigationController
override func prepare(for segue: UIStoryboardSegue, sender: Any?) {
if segue.identifier == "TrackDetailVC" {
if let detailsVC = segue.destination as? TrackDetailVC {
if let tr = sender as? newTracks {
detailsVC.track = tr
}
}
}
}

Answer 1

Yes, when your viewController is embedded in a UINavigationController you have to work through the parts of the chain until you get to the controller you want. Something like this should work:
override function prepare(for segue: UIStoryBoardSegue, sender: Any?) {
if segue.identifier == “TrackDetailVC” {
if let nav = segue.destinationVC as? UINavigationController {
if let detailsVC = nav.viewControllers[0] as? TrackDetailVC {
if let tr = sender as? newTracks {
detailsVC.track = tr
}
}
}
}
}

Answer 2

sender can't conform to type newTracks. Do some debugging with breakpoints and maybe see why this cast isn't working. Try making a variable called newTracks and explicityly giving it a type, and set it equal to what you want. Then make detailsVc.track = newTracks