Convert adress input in annotation on the map - SwiftUI

Question

I am a beginner so sorry for my question.

I have a map and annotations in a Datas file.

Now I would like the user to be able to register an address with a form.

How do I go from a normal address to a

location: CLLocationCoordinate2D(latitude: 48.8566, longitude: 2.3522)

Thanks for your help

Answer 1

Core Location has a "geocoder", which is what would take a street address and convert it to a CLLocationCoordinate2D.

This is from the official Apple documentation (https://developer.apple.com/documentation/corelocation/converting_between_coordinates_and_user-friendly_place_names):

func getCoordinate( addressString : String, 
        completionHandler: @escaping(CLLocationCoordinate2D, NSError?) -> Void ) {
    let geocoder = CLGeocoder()
    geocoder.geocodeAddressString(addressString) { (placemarks, error) in
        if error == nil {
            if let placemark = placemarks?[0] {
                let location = placemark.location!
                    
                completionHandler(location.coordinate, nil)
                return
            }
        }
            
        completionHandler(kCLLocationCoordinate2DInvalid, error as NSError?)
    }
}

Note that the preceding function uses callback functions and is an asynchronous function. That means that it does not return immediately -- instead, it finishes at an indeterminate time in the future and calls the callback function when it is finished.

---

Since you tagged the question SwiftUI, the following is a trivial example with SwiftUI:

import SwiftUI
import MapKit

class LocationManager : ObservableObject {
    @Published var location : CLLocationCoordinate2D?
    
    func convertAddress(address: String) {
        getCoordinate(addressString: address) { (location, error) in
            if error != nil {
                //handle error
                return
            }
            DispatchQueue.main.async {
                self.location = location
            }
        }
    }
    
    private func getCoordinate(addressString : String,
            completionHandler: @escaping(CLLocationCoordinate2D, NSError?) -> Void ) {
        let geocoder = CLGeocoder()
        geocoder.geocodeAddressString(addressString) { (placemarks, error) in
            if error == nil {
                if let placemark = placemarks?[0] {
                    let location = placemark.location!
                        
                    completionHandler(location.coordinate, nil)
                    return
                }
            }
                
            completionHandler(kCLLocationCoordinate2DInvalid, error as NSError?)
        }
    }
}

struct ContentView: View {
    @State var addressString = "1600 Pennsylvania Ave, Washington D.C."
    @StateObject private var locationManager = LocationManager()
    
    var body: some View {
        VStack {
            Text("Address: \(addressString)")
            if let location = locationManager.location {
                Text("Lat: \(location.latitude) Long: \(location.longitude)")
            }
        }.onAppear {
            locationManager.convertAddress(address: addressString)
        }
    }
}