graphRequest.start returns no data - ios

Question

I'm using the Facebook SDK for login with iOS using Swift 3.
This my code. The problem is that no values are returned.
import UIKit
class ViewController: UIViewController {
#IBOutlet weak var email: UITextField!
#IBOutlet weak var password: UITextField!
#IBOutlet weak var uLoginButton: UIButton!
let loginButton: FBSDKLoginButton = {
let button = FBSDKLoginButton()
button.readPermissions = ["email"]
return button;
}()
override func viewDidLoad() {
super.viewDidLoad()
view.addSubview(loginButton);
loginButton.center = view.center
loginButton.delegate = self
if (FBSDKAccessToken.current() != nil) {
fetchProfile();
}
self.style()
}
func fetchProfile(){
let graphRequest = FBSDKGraphRequest(graphPath: "me", parameters: ["fields" : "email, name, first_name, last_name, picture.type(large)"])
let connection = FBSDKGraphRequestConnection()
connection.add(graphRequest, completionHandler: { (connection, result, error) in
if error != nil {
//do something with error
print("No Data returned")
print(result)
} else {
//do something with result
print("Data returned")
print(result)
}
})
connection.start()
}
override func didReceiveMemoryWarning() {
super.didReceiveMemoryWarning()
// Dispose of any resources that can be recreated.
}
func style(){
self.email.layer.cornerRadius = 15;
self.password.layer.cornerRadius = 15;
self.uLoginButton.layer.cornerRadius = 15;
}
}
extension ViewController : FBSDKLoginButtonDelegate{
internal func loginButton(_ loginButton: FBSDKLoginButton!, didCompleteWith result: FBSDKLoginManagerLoginResult!, error: Error!) {
// when the login is correct!
print("Success login!");
fetchProfile()
}
internal func loginButtonDidLogOut(_ loginButton: FBSDKLoginButton!) {
FBSDKAppEvents.activateApp()
}
internal func loginButtonWillLogin(_ loginButton: FBSDKLoginButton!) -> Bool {
return true
}
}

Answer 1

In Swift 3, this is how you want to perform Graph Request.
Initialize FBSDKGraphRequest
Initialize FBSDKGraphRequestConnection
Add request to request connection
Start connection.
so,
let graphRequest = FBSDKGraphRequest(graphPath: "me", parameters: ["fields" : "email"])
let connection = FBSDKGraphRequestConnection()
connection.add(graphRequest, completionHandler: { (connection, result, error) in
if error != nil {
//do something with error
} else {
//do something with result
}
})
connection.start()