waitUntilAllTasksAreFinished error Swift

Question

I have this call in my loginViewController when Submit button is pressed:

let http = HTTPHelper()
    http.post(\"http://someUrl.com/Login/userEmail/\\(username.         


        

Answer 1

Your checkLogin function is being called on another thread, so you need to switch back to the main thread before you can call self.performSegueWithIdentifier. I prefer to use NSOperationQueue:

func checkLogin(succeed: Bool, msg: String) {
    if (succeed) {
        NSOperationQueue.mainQueue().addOperationWithBlock {
            self.performSegueWithIdentifier("logInTrue", sender: self)
        }        
    }
}

Alternate: xCode 10.1 1/2019

func checkLogin(succeed: Bool, msg: String) {
    if (succeed) {
        OperationQueue.main.addOperation {
            self.performSegue(withIdentifier: "logInTrue", sender: self)
           }        
      }
 }