Custom Protocol Swift - ios

Question

I have a Protocol
import UIKit
import Alamofire
import SwiftyJSON
protocol RequestProtocol: class {
func RequestConnection(json: JSON, status: Int, Message: String)
}
class API: UIViewController {
var delegate: RequestProtocol?
var json: JSON = []
override func viewDidLoad() {
super.viewDidLoad()
}
func RequestConnection() {
Alamofire.request(variablesClass.url).responseJSON { (response) -> Void in
switch response.result {
case .success:
let result = response.result.value
if response.response?.statusCode == 200 {
self.json = JSON(result!)
DispatchQueue.main.async(execute: {
self.delegate?.RequestConnection(json: self.json, status: (response.response?.statusCode)!, Message: "\(self.json["Message"])")
})
} else {
self.json = JSON(result!)
DispatchQueue.main.async(execute: {
self.delegate?.RequestConnection(json: self.json, status: (response.response?.statusCode)!, Message: "\(self.json["Message"])")
})
}
break;
case .failure(let error):
print(error)
break;
}
}
}
}
I have it called in my Main View
class ViewController: UIViewController, RequestProtocol {
func RequestConnection(json: JSON, status: Int, Message: String) {
func showAlertView()
}
override func viewDidLoad() {
super.viewDidLoad()
var senderDelegateRequest = API()
var receiverDelegateViewController = ViewController()
senderDelegateRequest.delegate = receiverDelegateRequestRegistro
senderDelegateRequest.RequestConnection()
}
func showAlertView(){
let alertView = UIAlertController(title: "You need to log in first", message: "To access the special features of the app you need to log in first.", preferredStyle: .alert)
alertView.addAction(UIAlertAction(title: "Login", style: .default, handler: { (alertAction) -> Void in
}))
alertView.addAction(UIAlertAction(title: "Cancel", style: .cancel, handler: nil))
present(alertView, animated: true, completion: nil)
}
Why the Protocol does'nt execute the function to display the alert.
There is some way that as soon as the protocol is executed it can execute some function

Answer 1

In your ViewController class you are conforming to the protocol RequestProtocol. This means you can be the delegate of API. You created an instance called receiverDelegateViewController but this instance isn't loaded yet. You should change:
senderDelegateRequest.delegate = receiverDelegateRequestRegistro
to
senderDelegateRequest.delegate = self
And the delegate in API should call RequestConnection, not your ViewController.