Add Swift annotations in MapKit with JSON file

Question

I'm trying to add annotations on a MapKitView from a JSON file. Here's my code :

// On récupère les valeurs JSON
func loadInitialData() {
    if let path = Bundle.main.path(forResource: "Playgrounds", ofType: "json") {
        do {
            let data = try Data(contentsOf: URL(fileURLWithPath: path), options: .mappedIfSafe)
            let jsonResult = try JSONSerialization.jsonObject(with: data, options: .mutableLeaves)
            print(jsonResult)
            let jsonResultAs = jsonResult as? Dictionary<String, AnyObject>
            print(jsonResultAs!)
            let playground = jsonResultAs!["playgrounds"] as? [Any]
            print(playground!)
            // 5
            let validWorks = playground.flatMap { Playground(json: $0) }
            playgrounds.append(validWorks!)
        } catch {
            // handle error
        }
    }

This code is executed. Then it goes to :

init?(json: [Any]) {
    // json[16] = on prend le 16ème paramètre de la réponse json. Pour le titre, s'il est null, on en met un par défaut
    self.title = json[6] as? String ?? "Aucun nom"
    //self.locationName = json[3] as! [String]()
    self.locationName = json[2] as? String ?? "Lieu non défini"
    //self.discipline = json[2] as! String
    self.discipline = ""
    // On récupère latitude et longitude en string puis on convertit en double
    if let latitude = Double(json[4] as! String),
        let longitude = Double(json[5] as! String) {
        self.coordinate = CLLocationCoordinate2D(latitude: latitude, longitude: longitude)
    } else {
        self.coordinate = CLLocationCoordinate2D()
    }
}

The error is on the line if let latitude = Double(json[4] as! String)

I cant figured out why it's not working, i'm following this tutorial but I know I miss something... I hope someone can help me !

My JSON struct file :

[{
    ComLib = Ambronay;
    DepCode = 1;
    DepLib = Ain;
    EquEclairage = "-1";
    EquGpsX = "5.3625";
    EquGpsY = "46.0075";
    InsNom = "Terrain de basket";
    NatureLibelle = Decouvert;
    NatureSolLib = Sable;
}, {
    ComLib = Ambutrix;
    DepCode = 1;
    DepLib = Ain;
    EquEclairage = "-1";
    EquGpsX = "5.34";
    EquGpsY = "45.93889";
    InsNom = "Ecole Primaire";
    NatureLibelle = Decouvert;
    NatureSolLib = Bitume;
},
etc...
}]

Thanks.

Answer 1

This line

Double(json[4] as! String)

crashes because json is an array of dictionaries and you want to force cast the dictionary to string , for old way you may need

var allCoor = [CLLocationCoordinate2D]()

init?(json: [Any]) { 

    if let content = json as? [[String:Any]] { 
       content.forEach {
          if let latitude = $0["EquGpsX"] as? String , let longitude = $0["EquGpsY"] as? String
             self.allCoor.append( CLLocationCoordinate2D(latitude:Double(latitude)!, longitude: Double(longitude)!))
          }
          else {
            ///// 
          } 
       }
    } 
}

But the correct way is using Codable