Swift fetch custom annotation information - swift

Question

I'm trying to present a view controller with an object within annotation didSelect function. But it's returning nil when I try to print the post.id within the newly presented viewcontroller. If I print post.id within the addAnnotation function it returns fine.
func addAnnotations(post: Post, title: String?, locationName: String?, coords: [CLLocation]) {
for coord in coords {
let CLLCoordType = CLLocationCoordinate2D(latitude: coord.coordinate.latitude,
longitude: coord.coordinate.longitude);
let anno = MKPointAnnotation()
anno.coordinate = CLLCoordType
if title == "" {
anno.title = locationName
} else {
anno.title = title
}
mapView.addAnnotation(anno)
}
}
let activityPreview = ActivityPreviewLauncher()
func mapView(_ mapView: MKMapView, didSelect view: MKAnnotationView) {
//Returns an error
guard let post = view.annotation?.post else { return }
activityPreview.showActivityPreview()
activityPreview.homeController = self
activityPreview.post = post
}
func mapView(mapView: MKMapView, viewForAnnotation annotation: MKAnnotation) -> MKAnnotationView? {
if annotation is MKUserLocation{
return nil
} else{
let pinIdent = "Pin"
var pinView: MKPinAnnotationView
if let dequeuedView = mapView.dequeueReusableAnnotationView(withIdentifier: pinIdent) as? MKPinAnnotationView {
dequeuedView.annotation = annotation
pinView = dequeuedView
} else {
pinView = MKPinAnnotationView(annotation: annotation, reuseIdentifier: pinIdent)
}
return pinView
}
}

Answer 1

Value of type 'MKAnnotation' has no member 'post'. You have to subclass MKPointAnnotation
class MyAnno: MKPointAnnotation {
var post: Post? = nil
}
in func addAnnotations override your code to
let CLLCoordType = CLLocationCoordinate2D(latitude: coord.coordinate.latitude,
longitude: coord.coordinate.longitude);
let anno = MyAnno()
anno.coordinate = CLLCoordType
anno.post = post
if title == "" {
anno.title = locationName
} else {
anno.title = title
}
mapView.addAnnotation(anno)
then in didSelect check type of your annotation
guard
let anno = view.annotation as? MyAnno,
let post = anno.post
else { return }
smth like this