How to parse JSON using Codable in Swift? - json

Question

I am able to parse JSON using JSONSerialization, but unable to parse with Codable.
the json look like this:
[
{
"id": 1,
"name": "Leanne Graham",
"username": "Bret",
"email": "Sincere#april.biz",
}
Please help me with the code.
able to parse using JSONSerialization: data coming
Unable to parse JSON with Codable: data not coming
struct jsonDataModel: Codable{
var name: String
var userName: String
var email: String
init(name: String, username: String, email: String){
self.name = name
self.userName = username
self.email = email
}
}
class WebviewViewController: UIViewController, WKNavigationDelegate {
#IBOutlet weak var testWebView: WKWebView!
//var itemsArray = [jsonDataModel]()
override func viewDidLoad() {
super.viewDidLoad()
serviceCall()
}
func serviceCall()
{
let jsonString = "https://jsonplaceholder.typicode.com/users"
let jsonData = jsonString.data(using: .utf8)!
do {
let jsonDecoder = JSONDecoder()
let user = try jsonDecoder.decode(jsonDataModel.self, from: jsonData)
print("all data \(user)")
print("Hello \(user.name), \(user.userName), \(user.email) ")
} catch {
print("Unexpected error: \(error).")
}
}
}
Please help me to parse json with codable.

Answer 1

Try this example.
import UIKit
import Foundation
class ViewController: UIViewController {
override func viewDidLoad() {
super.viewDidLoad()
let url = URL(string: "https://jsonplaceholder.typicode.com/users")!
let task = URLSession.shared.dataTask(with: url) {(data, response, error) in
guard let data = data else { return }
do{
let jsonDataModels = try JSONDecoder().decode([JSONDataModel].self, from: data)
print(String(data: data, encoding: .utf8)!)
print("jsonDataModels: \(jsonDataModels)")
}catch{}
}
task.resume()
}
}
struct JSONDataModel: Codable {
let id: Int
let name, username, email: String
let address: Address
let phone, website: String
let company: Company
}
struct Address: Codable {
let street, suite, city, zipcode: String
let geo: Geo
}
struct Geo: Codable {
let lat, lng: String
}
struct Company: Codable {
let name, catchPhrase, bs: String
}

Answer 2

First of all, if you're using a URL, then to get data you need to use a networking api. URLSession is the iOS provided api to perform network operations like download/upload.
So, just using Codable doesn't make any sense. You need to first have the data in order to parse it with Codable.
Here is the model,
struct Model: Codable {
let id: Int
let name, username, email: String
}
And you can use it in your controller's viewDidLoad() method,
if let url = URL(string: "https://jsonplaceholder.typicode.com/users") {
URLSession.shared.dataTask(with: url) { (data, urlResponse, error) in
if let data = data {
do {
let response = try JSONDecoder().decode([Model].self, from: data)
print(response.map({ $0.name })) //prints all the names
} catch {
print(error)
}
}
}.resume()
}