Unable to GET from JSON API - json

Question

I have tried following a variety of tutorials, and I am unable to progress on getting data from this API. I did manage to succeed on a simpler JSON ], but this one is eating up my time.
First, the JSON:
{
"object": {
"array": [
{
"id": 48,
"name": "Job No.# 48",
"description": "blah",
"start_at": "2021-03-05T13:15:00.000+11:00",
"end_at": "2021-03-05T14:15:00.000+11:00",
"map_address": "blah road"
},
{
"id": 56,
"name": "Job No.# 56",
"description": "Do it",
"start_at": "2021-06-22T11:30:00.000+10:00",
"end_at": "2021-06-22T13:30:00.000+10:00",
"map_address": " blah"
}
],
"person": {
"id": 52,
"first_name": "Bob",
"last_name": "Newby",
"mobile": "0401111111",
"email": "bob#mail.com"
}
}
}
And now my attempt at decoding it:
struct api_data: Codable {
let object : Object
}
struct Object: Codable {
let array : [array]
let person : Person
}
struct array: Codable, Identifiable {
let id : Int?
let start_at, end_at : Date?
let duration : Float?
let cancellation_type : String?
let name, description, address, city, postcode, state : String?
}
struct Person: Codable, Identifiable {
let id : Int?
let first_name, last_name, mobile, email : String?
}
class FetchShifts: ObservableObject {
#Published var shifts = [Shifts]()
init() {
let url = URL(string: "realURLhiddenForPrivacy")!
var request = URLRequest(url: url)
request.httpMethod = "GET"
request.setValue("myToken", forHTTPHeaderField: "Authorization")
URLSession.shared.dataTask(with: request) {(data, response, error) in
do {
if let array_data = data {
let array_data = try JSONDecoder().decode([array].self, from: array_data)
DispatchQueue.main.async {
self.array = array_data
}
} else {
print("No data")
}
} catch {
print(error)
}
}.resume()
}
}
And how I attempt to present it:
#ObservedObject var fetch = FetchArray()
var body: some View {
VStack {
List(array.shifts) { shft in
VStack(alignment: .leading) {
Text(shft.name!)
}
}
}
}
}
}
Any help is appreciated, not sure where it is I go wrong here, been at it for 5-7 hours going through tutorials.

Answer 1

I always recommend using app.quicktype.io to generate models from JSON if you're unfamiliar with it. Here's what it yields:
// MARK: - Welcome
struct Welcome: Codable {
let status: String
let payload: Payload
}
// MARK: - Payload
struct Payload: Codable {
let shifts: [Shift]
let worker: Worker
}
// MARK: - Shift
struct Shift: Codable, Identifiable {
let id: Int
let name, shiftDescription, startAt, endAt: String
let mapAddress: String
enum CodingKeys: String, CodingKey {
case id, name
case shiftDescription = "description"
case startAt = "start_at"
case endAt = "end_at"
case mapAddress = "map_address"
}
}
// MARK: - Worker
struct Worker: Codable {
let id: Int
let firstName, lastName, mobile, email: String
enum CodingKeys: String, CodingKey {
case id
case firstName = "first_name"
case lastName = "last_name"
case mobile, email
}
}
Then, to decode, you'd do:
do {
let decoded = try JSONDecoder().decode(Welcome.self, from: shift_data)
let shifts = decoded.payload.shifts
} catch {
print(error)
}
Note that in Swift, it's common practice to use camel case for naming, not snake case, so you'll see that CodingKeys does some conversion for that (there are automated ways of doing this as well).
Update, based on comments:
Your code would be:
if let shiftData = data {
do {
let decoded = try JSONDecoder().decode(Welcome.self, from: shiftData)
DispatchQueue.main.async {
self.shifts = decoded.payload.shifts
}
} catch {
print(error)
}
}

Answer 2

Instead of defining custom keys, you can automatically use
keyDecodingStrategy = .convertFromSnakeCase for your JSON decoder, and could specify custom date format or even throw a custom error in your decoder implementation.
struct Worker: Codable {
let id: Int
let firstName: String?
let lastName: String?
let mobile: String?
let email: String?
}
struct Shift: Codable, Identifiable {
let id: Int
let name: String?
let description: String?
let startAt: Date?
let endAt: Date?
let mapAddress: String?
}
struct Payload: Codable {
let shifts: [Shift]?
let worker: Worker?
}
struct Response: Codable {
let status: String
let payload: Payload?
}
class MyCustomDecoder: JSONDecoder {
override init() {
super.init()
self.keyDecodingStrategy = .convertFromSnakeCase
let dateFormatter = DateFormatter()
dateFormatter.dateFormat = "yyyy-MM-dd'T'HH:mm:ss.SSSZ"
self.dateDecodingStrategy = .formatted(dateFormatter)
}
}
// Usage
if let data = json.data(using: .utf8) {
let response = try MyCustomDecoder().decode(Response.self, from: data)
print(response)
}