AddCardViewController not going away after completion - ios

Question

I'm pretty new to iOS Programming, and I'm stuck on this little portion here.
I'm basically trying to use Stripe in my iOS application. The user inputs an amount they wish to pay, press NEXT and they input their card details. All of this is going well so far - I can get the AddCardViewController to show up, and input their card details.
The code makes it all the way to verifying the card token and accepting the payment; which is wonderful, but then the problem comes that the AddCardViewController doesn't go away afterward.
When I was trying it out on a demo, it worked perfectly fine, but on my app it doesn't work at all! The app just gets stuck there on the AddCardViewController. Hitting cancel does nothing, there's no display message, and submitting the card details again just double bills the user.
What am I doing wrong?
For further info, this is my code:
StripeClient.shared.sendPostRequest(with: token, amount: amount, description: description) { result in
switch result {
// 1
case .success:
completion(nil)
let alertController = UIAlertController(title: "Congrats",
message: "Your payment was successful!",
preferredStyle: .alert)
let alertAction = UIAlertAction(title: "OK", style: .default, handler: { _ in
self.navigationController?.popViewController(animated: true)
})
alertController.addAction(alertAction)
self.present(alertController, animated: true)
self.view.makeToast("Your payment was successful! We will be sending you a receipt to your email shortly.")
// 2
case .failure(let error):
completion(error)
}
}
I made my custom post request because I couldn't get the one offered by the demo to work, but I can say with 100% certainty that the code enters case .success successfully - I tested this already. But just in case, this is my .sendPostRequest method:
func sendPostRequest(with token: STPToken, amount: Double, description: String, completion: #escaping (Result) -> Void) {
//declare parameter as a dictionary which contains string as key and value combination. considering inputs are valid
let params: [String: Any] = [
"stripeToken": token.tokenId,
"amount": amount,
"currency": Constants.defaultCurrency,
"description": description
]
//create the url with URL
let url = URL(string: "<this-is-my-url.com>")! //change the url
//create the session object
let session = URLSession.shared
//now create the URLRequest object using the url object
var request = URLRequest(url: url)
request.httpMethod = "POST" //set http method as POST
do {
request.httpBody = try JSONSerialization.data(withJSONObject: params, options: .prettyPrinted) // pass dictionary to nsdata object and set it as request body
} catch let error {
print(error.localizedDescription)
}
request.addValue("application/json", forHTTPHeaderField: "Content-Type")
request.addValue("application/json", forHTTPHeaderField: "Accept")
//create dataTask using the session object to send data to the server
let task = session.dataTask(with: request as URLRequest, completionHandler: { data, response, error in
guard error == nil else {
return
}
guard let data = data else {
return
}
do {
//create json object from data
//print(data)
if let json = try JSONSerialization.jsonObject(with: data, options: .mutableContainers) as? [String: Any] {
//print(json)
// handle json...
//print(json["response"]!)
if let responseString = try json["response"] as? String {
if responseString == "SUCCESS" {
completion(Result.success)
} else {
completion(Result.failure(IntParsingError.overflow))
}
}
}
} catch let error {
print(error.localizedDescription)
}
})
task.resume()
}
I would really, really, REALLY appreciate the help!

Answer 1

1- You need
DispatchQueue.main.async {
completion(Result.success)
}
As session.dataTask(with: runs in background thread
2- For this to run
self.navigationController?.popViewController(animated: true)
verify the vc is embedded inside a navigation and you presented it with push not present func of the previous vc
Edit:
When you present do
self.dismiss(animated: true, completion: nil)