Swift scoping outside of a function - swift

Question

I have a singleton URLSession that is parsing the response data into a dictionary. I want to use a single value from that dictionary in a subsequent piece of code, but cannot figure out how to pass the value out from the scope it's currently in.
Here is the code as it stands now:
let task = URLSession.shared.dataTask(with: request) { data, response, error in
guard error == nil else {
debugPrint ("error: \(error!)")
return
}
guard let content = data else {
debugPrint("No data")
return
}
guard let json = (try? JSONSerialization.jsonObject(with: content, options: JSONSerialization.ReadingOptions.mutableContainers)) as? [String: Any] else {
debugPrint("Not containing JSON")
return
}
if let idToken = json["id_token"] as? String {
let privateToken = idToken;
debugPrint("Gotten json response dictionary is \(idToken)")
}
}
task.resume()
return privateToken
Currently there is an IDE error on return privateToken saying that I am using an unresolved identifier: privateToken.
How can I take the string idToken and return it as a privateToken for use elsewhere?

Answer 1

Could you use a completion handler like:
func getPrivateToken(completion: #escaping(String) -> (), failure: #escaping (Error) -> ()) {
URLSession.shared.dataTask(with: request) { data, response, error in
guard error == nil else {
debugPrint ("error: \(error!)")
failure(error)
return
}
guard let content = data else {
debugPrint("No data")
failure(NSError(domain: "Your error message here.", code: 401, userInfo: nil))
return
}
guard let json = (try? JSONSerialization.jsonObject(with: content, options: JSONSerialization.ReadingOptions.mutableContainers)) as? [String: Any] else {
debugPrint("Not containing JSON")
failure(NSError(domain: "Your error message here.", code: 401, userInfo: nil))
return
}
if let idToken = json["id_token"] as? String {
completion(idToken)
debugPrint("Gotten json response dictionary is \(idToken)")
}
}.resume()
}
And use it like so:
func exampleFunction() {
self.getPrivateToken(completion: { (token) in
// Do what ever you need with the token here.
print("ID token is: \(token)")
}) { (error) in
// Present error here
}
}