How do I pass JSON data between controller in Swift 3.0? - ios

Question

I have these JSON data:
{"login":"ET001","email":"email#try.com"}
In Swift 3.0, I created two files which are LoginVC and ViewController.
ViewController can only be accessed after LoginVC verified the credentials. So far I managed to make the login access the ViewController page based on "success" JSON data from database.
But my next goal is to pass the JSON data "[login]" from LoginVC into ViewController.
In ViewController, I created UILabel "loginLbl" to display the JSON value from LoginVC.
How do update my code?
LoginVC.swift
import UIKit
class LoginVC: UIViewController {
#IBOutlet var _login: UITextField!
#IBOutlet var _pass: UITextField!
#IBOutlet var outputLbl: UILabel!
var login: String!
var pass: String!
override func viewDidLoad() {super.viewDidLoad()}
override func prepare(for segue: UIStoryboardSegue, sender: Any?) {
if segue.identifier == "tocey"{
if let destination = segue.destination as? ViewController {
destination.passedData = self.outputLbl.text
print("Sender value is : \(sender)")
}
}
}
#IBAction func loginData(_ sender: Any) {
login = _login.text
pass = _pass.text
if(login == "" || pass == "") {
return
}
else {
let url = URL(string: "http://localhost/login.php")
let session = URLSession.shared
let request = NSMutableURLRequest(url: url! as URL)
request.httpMethod = "POST"
let paramToLogin = "login=\(login!)&pass=\(pass!)"
request.httpBody = paramToLogin.data(using: String.Encoding.utf8)
let task = session.dataTask(with: request as URLRequest, completionHandler: {
(data, response, error) in
if error != nil {
return
}
else {
do {
if let json = try JSONSerialization.jsonObject(with: data!) as? [String: String] {
DispatchQueue.main.async {
let success = Int(json["success"]!)
let loginvaluefromdb = json["login"]
if(success == 1){
self.outputLbl.text = loginvaluefromdb;
let abc = json["login"]
self.performSegue(withIdentifier: "tocey", sender: abc)
return
}
}
}
}
catch {
}
}
})
task.resume()
}
}
}
ViewController.swift
import UIKit
class ViewController: UIViewController {
#IBOutlet var loginLbl: UILabel!
var passedData: String!
override func viewDidLoad() {
super.viewDidLoad()
loginLbl.text = passedData
}
}
How to pass it into UILabel loginLbl?

Answer 1

Once you identify that login data is correct in your response you need to push your viewController in navigation controller and take one dictionary in your viewController and assign json to that dictionary.
if let json = try JSONSerialization.jsonObject(with: data!) as? [String: String] {
DispatchQueue.main.async {
let success = Int(json["success"]!)
let loginvaluefromdb = json["login"]
if(success == 1){
let viewController = self.storyboard?.instantiateViewController(withIdentifier: "yourViwController") as! yourViwController
viewController.dictJson = json
self.navigationController?.pushViewController(viewController, animated: true)
}

Answer 2

if(success == 1){
self.outputLbl.text = loginvaluefromdb;
// Here you trigger the segue
self.performSegue(withIdentifier: "goToViewController", sender: loginvaluefromdb)
return
}
You need to pass the data in prepare for segue method :
Here is the editec code
override func prepare(for segue: UIStoryboardSegue, sender: Any?) {
if segue.identifier == "goToViewController" {
if let destination = segue.destination as? ViewController {
// Here you will copy tha data you want to pass
destination.passedData = sender as? String
print("Sender Value: \(sender)")
}
}
}