Swift and JSON driving me crazy - json

Question

I am really getting stuck on this.
I have created a JSON service, that returns data like this:
[
{
"docNameField": "Test",
"docNumField": 22832048,
"docVerField": 1,
"docDataBaseField": "Legal",
"docCheckedOutWhenField": "03/05/2020",
"whereCheckedOutField": "PC0X8J9RD"
}
]
This is Postman output.
No matter how I try, I cannot seem to be able to put together the correct combination og HTTP call, deserialization, types and so on to get a list of objects out in the end.
This func below outputs this:
JSON String: Optional("[{\"docNameField\":\"Test\",\"docNumField\":22832048,\"docVerField\":1,\"docDataBaseField\":\"Legal\",\"docCheckedOutWhenField\":\"03/05/2020\",\"whereCheckedOutField\":\"PC0X8J9RD\"}]")
func LoadLockedDocumentsByDocnum(docNum:Int32) {
let json: [String: Any] = ["action":"getCheckedOutDocuments","adminUserName":"\(APPuserName)","adminPassword":"\(APPuserPassword)","adminDomain":"\(APPuserDomain)","applicationKey":"19730905{testKey}","searchTerm":docNum]
let jsonData = try? JSONSerialization.data(withJSONObject: json)
self.documentEntries.removeAll()
let url = URL(string: "https://{URL}//CheckOut")!
var request = URLRequest(url: url)
request.addValue("application/x-www-form-urlencoded", forHTTPHeaderField: "Content-Type") //Optional
request.httpMethod = "POST"
request.setValue("application/json", forHTTPHeaderField: "Content-Type")
request.httpBody = jsonData
let session = URLSession.shared
let dataTask = session.dataTask(with: request) { (data: Data?, response: URLResponse?, error: Error?) in
if let resultat = response as! HTTPURLResponse?{
if resultat.statusCode == 200{
if error != nil {
}
else {
print(data!)
if let nydata = data{
print("JSON String: \(String(data: data!, encoding: .utf8))")
}
}
}}
}
dataTask.resume()
}

Answer 1

You seem to have come pretty close. To get a list of objects out, you first need to declare that object:
struct MyResponseObject: Decodable { // please give this a better name
let docNameField: String
let docNumField: Int
let docVerField: Int
let docDataBaseField: String
let docCheckedOutWhenField: Date
let whereCheckedOutField: String
}
And then use a JSONDecoder to deserialise the JSON. Instead of:
print("JSON String: \(String(data: data!, encoding: .utf8))")
write:
let decoder = JSONDecoder()
let formatter = DateFormatter()
formatter.dateFormat = "MM/dd/yyyy"
decoder.dateDecodingStrategy = .formatted(formatter)
do {
// here's your list of objects!
let listOfObjects = try decoder.decode([MyResponseObject].self, from: data!)
} catch let error {
print(error) // an error occurred, you can do something about it here
}