Removing Data on Maps with different view controllers - swift

Question

I am really struggling on an issue that I think is rather interesting and quite difficult. My application lets the user create annotation locations within a Mapview. They also have the option to edit and delete these locations in another modal view controller.
The issue I am facing is that when the user presses delete, which removes the location from firebase, the annotation is still displayed upon the map. I cannot reload my annotation data within the view did appear as this does not suit my application. I cant have my annotations being reloaded every time I bring up the Mapview.
I need to figure out a way to implement an annotation reload when the delete button is pressed. However, as this happens within my delete view controller (which does not contain the mapView) I cannot use the reload function. Is there a way to connect view controllers so that I can apply the reload function when delete is pressed?
Updated Code **
This is my map view controller:
class ViewController: UIViewController, SideBarDelegate, MGLMapViewDelegate, DeleteVCDelegate {
let EditSaveSpotController = UIStoryboard(name: "Main", bundle: nil).instantiateViewController(withIdentifier: "EditVC") as! EditSaveSpotViewController
override func viewDidLoad() {
super.viewDidLoad()
EditSaveSpotController.delegate = self
}
func wholeRefresh() {
let uid = FIRAuth.auth()!.currentUser!.uid
let userLocationsRef = FIRDatabase.database().reference(withPath: "users/\(uid)/personalLocations")
userLocationsRef.observe(.value, with: { snapshot in
for item in snapshot.children {
guard let snapshot = item as? FIRDataSnapshot else { continue }
let newSkatepark = Skatepark(snapshot: snapshot)
self.skateparks.append(newSkatepark)
self.addAnnotation(park: newSkatepark)
}
})
if let annotations = mapView.annotations {
mapView.removeAnnotations(annotations)
}
for item in skateparks {
self.addAnnotation(park: item)
}
}
This is my delete view controller:
import UIKit
import Firebase
protocol DeleteVCDelegate {
func wholeRefresh()
}
class EditSaveSpotViewController: UIViewController {
var delegate: DeleteVCDelegate?
#IBAction func deleteSkateSpot(_ sender: Any) {
ref = FIRDatabase.database().reference(withPath: "users").child(Api.User.CURRENT_USER!.uid).child("personalLocations/\(parkId!)")
ref.observe(.value, with: { (snapshot) in
self.ref.setValue(nil)
self.dismiss(animated: true, completion: nil)
self.delegate?.wholeRefresh()
// self.delegate?.mainRefresh()
print("CheckWorking")
})
}
}

Answer 1

This is very high level and I did not have a chance to verify but it should be enough to get you going:
Modal Delete View
protocol DeleteVCDelegate {
func mainRefresh()
}
class DeleteVC: UIViewController {
var delegate: DeleteVCDelegate?
//your delete code
#IBAction func deleteSkateSpot(_ sender: Any) {
ref = FIRDatabase.database().reference(withPath: "users").child(Api.User.CURRENT_USER!.uid).child("personalLocations/\(parkId!)")
ref.observe(.value, with: { (snapshot) in
self.ref.setValue(nil)
//call to delegate
self.delegate?.mainRefresh()
})
}
}
MapView Class (implement DeleteVCDelegate)
class mapVC: MKMapViewDelegate, DeleteVCDelegate{
//when you present your DeleteVC set its delegate to the map view
let vc=(self.storyboard?.instantiateViewController(withIdentifier: "deleteVC"))! as! DeleteVC
//set the delegate
vc.delegate=self
//present deleteVC
self.present(vc, animated: true, completion:nil)
//implement delegate method of DeleteVC
func mainRefresh(){
//dismiss modal
self.dismiss(animated: true) {
//update view
self.loadLocations()
self.annotationRefresh()
}
}
}