stop urlRequest onViewDisappear - swift

Question

I load my json info from my server as follows, but when I click away to a different page too soon, the request keeps trying in the background and there is a warning that the viewController can't be found anymore. How would I cancel all requests onViewDisappear?
if let requestURL = URL(string: "https://www.example.com/file.php") {
var urlRequest = URLRequest(url: requestURL)
urlRequest.httpMethod = "POST"
let postString = "email=\(loginUsername.text!)"
urlRequest.httpBody = postString.data(using: .utf8)
let session = URLSession.shared
let task = session.dataTask(with: urlRequest as URLRequest) { (data, response, error) in
if let data = data {
do {
if let jsonResult = try JSONSerialization.jsonObject(with: data, options: []) as? [String:Any] {
// Async Stuff
DispatchQueue.main.async{
// do things
}
DispatchQueue.main.async(execute: {
})
}
} catch {
print("Error: \(error)")
}
}
}
task.resume()
}

Answer 1

Save your requests somewhere and then on moving away from the controller call:
task.cancel()

Answer 2

class DataCall {
var task: URLSessionDataTask?
func load() {
guard let requestURL = URL(string: "https://www.example.com/file.php") else { return }
var urlRequest = URLRequest(url: requestURL)
urlRequest.httpMethod = "POST"
let postString = "email=\(loginUsername.text!)"
urlRequest.httpBody = postString.data(using: .utf8)
let session = URLSession.shared
task = session.dataTask(with: urlRequest as URLRequest) { (data, response, error) in
if let data = data {
do {
if let jsonResult = try JSONSerialization.jsonObject(with: data, options: []) as? [String:Any] {
// Async Stuff
DispatchQueue.main.async{
// do things
}
}
} catch {
print("Error: \(error)")
}
}
}
task.resume()
}
func stopTask() {
task.cancel()
}
}
Then in your viewWillDissapear you call dataCall.stopTask().