How to access a dictionary value with Swift 3? - swift

Question

So since the release of Swift 3, a part of my code where I access a dictionary isn't working anymore, here is the code with the previous release of swift:
var locationDict: NSDictionary?//location dictionary
if let getLocation = item.value?["Location"]{locationDict = getLocation as? NSDictionary}
//get dictionary values
let getLatitude = locationDict?.valueForKey("latitude") as! Double
let getLongitude = locationDict?.valueForKey("longitude") as! Double
Now with the new release I'm not sure how to rewrite "getLocation". I only rewrote the last two lines with the new syntax:
//get dictionary values
let getLatitude = locationDict?.value(forKey: "latitude") as! Double
let getLongitude = locationDict?.value(forKey: "longitude") as!
I am using Firebase, this is the complete function: (it adds an array of annotations to a map)
func setAnnotations(){
//get data
ref.child("Stores").observe(.value, with: { (snapshot) in
self.mapView.removeAnnotations(self.annArray)
for item in snapshot.children {
let annotation = CustomAnnotation()
//set all data on the annotation
annotation.subtitle = (snapshot.value as? NSDictionary)? ["Category"] as? String
annotation.title = (snapshot.value as? NSDictionary)? ["Name"] as? String
annotation.annImg = (snapshot.value as? NSDictionary)? ["Logo"] as? String
var locationDict: NSDictionary?//location dictionary
if let getLocation = item.value?["Location"]{locationDict = getLocation as? NSDictionary}
let getLatitude = locationDict?.value(forKey: "latitude") as! Double
let getLongitude = locationDict?.value(forKey: "longitude") as! Double
annotation.coordinate = CLLocationCoordinate2D(latitude: getLatitude, longitude: getLongitude)
self.annArray.append(annotation)
self.mapView.addAnnotation(annotation)
}
})
}

Answer 1

Try this:-
func setAnnotations(){
//get data
FIRDatabase.database().reference().child("Stores").observe(.value, with: { (snapshot) in
self.mapView.removeAnnotations(self.annArray)
for item in snapshot.children{
if let itemDict = (item as! FIRDataSnapshot).value as? [String:AnyObject]{
annotation.subtitle = itemDict["Category"] as! String
annotation.title = itemDict["Name"] as! String
annotation.annImg = itemDict["Logo"] as! String
if let locationDict = itemDict["Location"] as? [String:AnyObject]{
let getLatitude = locationDict["latitude"] as! Double
let getLongitude = locationDict["longitude"] as! Double
annotation.coordinate = CLLocationCoordinate2D(latitude: getLatitude, longitude: getLongitude)
self.annArray.append(annotation)
self.mapView.addAnnotation(annotation)
}
}
}
})
}

Answer 2

Things get substantially easier if you cast to a type-safe dictionary, e.g.:
snapshot.value! as! [String:Any]
For a slightly larger example, see the code from this answer I wrote earlier today:
ref!.observe(.value, with: { (snapshot) in
for child in snapshot.children {
let msg = child as! FIRDataSnapshot
print("\(msg.key): \(msg.value!)")
let val = msg.value! as! [String:Any]
print("\(val["name"]!): \(val["message"]!)")
}
})