I wrote the following function below to display alerts through my project. Every time i check for an error in a form i display the alert when the user clicks submit. I want to simply show the alert, but not unwind the pervious segue. I want to stay at the current screen and give the user the opportunity to complete the form. Right now when the user clicks submit, it displays the alert ..but when i click the ok button to dismiss the alert it immediately unwinds the segue to the previous screen.
I have included the UIAlertViewDelegate in the class.... any ideas why this might be happening?
func displayAlert(title:String, error:String) {
var alert = UIAlertController(title: title, message: error, preferredStyle: UIAlertControllerStyle.Alert)
alert.addAction(UIAlertAction(title: "OK", style: .Default, handler: { action in
self.dismissViewControllerAnimated(true, completion: nil)
}))
self.presentViewController(alert, animated: true, completion: nil)
}
Never mind.
func displayAlert(title:String, error:String) {
var alert = UIAlertController(title: title, message: error, preferredStyle: UIAlertControllerStyle.Alert)
alert.addAction(UIAlertAction(title: "OK", style: .Default, handler: { action in
//comment out this line and it will still work. It will not segue back to the previous screen.
//self.dismissViewControllerAnimated(true, completion: nil)
}))
self.presentViewController(alert, animated: true, completion: nil)
}
Related
I have an alert and right after the alert is shown, I would like to present a different viewFinder. The doSomething() function is fired, "TEST" is printed, but the new viewfinder is not presented. What am I missing?
Alert
let alert = UIAlertController(title: "Sorry", message: "Booked out.",
preferredStyle: UIAlertControllerStyle.alert)
alert.addAction(UIAlertAction(title: "OK", style:
UIAlertActionStyle.default, handler: nil))
self.present(alert, animated: true, completion: self.doSomething)
content func doSomething()
print("TEST")
let details = storyboard?.instantiateViewController(withIdentifier: "ViewLimo2")
details?.transitioningDelegate = slideAnimatorRight
present(details!, animated: true, completion: nil)
The completion block on a view controller doesn't fire when the view controller is dismissed. It fires when the view controller finishes presenting (e.g. it has finished with viewDidAppear).
Honestly, I'd expect this to crash, since you're attempting to present while the alert is still presenting.
In any case, you need to wait until the dismissal of the UIAlertController before you try to present the next View Controller.
You could do it in the handler for the OK action:
let alert = UIAlertController(title: "Sorry", message: "Booked out.",
preferredStyle: UIAlertControllerStyle.alert)
alert.addAction(UIAlertAction(title: "OK", style:
UIAlertActionStyle.default, handler: doSomething))
self.present(alert, animated: true, completion: nil)
...
func doSomething(action:UIAlertAction) {
/// present the next VC here
}
I'm having a homeView which is the initial view to appear when app launches. In its viewWillAppear() method I check if the user is logged in. If not, he's redirected to login page and if he's not yet registered he'll be directed to sign-up page. I get an error when user clicks the sign-up button. The signUPView appears but it gives a warning that Attempt to present loginViewController on signupViewController whose view is not in the window hierarchy. I have show detail segues between sign-up and login views.
I'm performing the segue after uialert is presented.
I got solutions to put the code in viewDidAppear or ViewWillAppear method but I'm presenting the viewControllers upon button press. So I can't use these methods.
I have searched for a lot of solutions but unable to get the right one.
Please help!
Thank you.
segue triggering code from sign-up :
dispatch_async(dispatch_get_main_queue()) {
if self.registerSuccess == true {
let alert = UIAlertController(title: "Registered!", message: "You have registered successfully!", preferredStyle: UIAlertControllerStyle.Alert)
alert.addAction(UIAlertAction(title: "OK", style: .Default, handler: { (action) -> Void in
self.dismissViewControllerAnimated(true, completion: nil)
self.nameTextField.text = ""
self.emailTextField.text = ""
self.passwordTextField.text = ""
self.performSegueWithIdentifier("loginSegue", sender: self)
}))
self.presentViewController(alert, animated: true, completion: nil)
} else {
let alert = UIAlertController(title: "Registration Failed!", message: "Please try again", preferredStyle: UIAlertControllerStyle.Alert)
alert.addAction(UIAlertAction(title: "OK", style: .Default, handler: { (action) -> Void in
self.dismissViewControllerAnimated(true, completion: nil)
}))
self.presentViewController(alert, animated: true, completion: nil)
}
}
screenshot of my storyboard
I have a screen with a collection view of items. If the user has not selected anything, I want an alert to pop up, prompting them to choose something. If they have chosen something, I want an alert to pop up, asking if they are ready to move on? Below is my code for this:
if (isSelected) {
// create the alert
let alert = UIAlertController(title: "Create", message: "Make sure to select at least one item.", preferredStyle: UIAlertControllerStyle.Alert)
alert.addAction(UIAlertAction(title: "OK", style: UIAlertActionStyle.Cancel, handler: { action in
alert.dismissViewControllerAnimated(true, completion: nil)
}))
self.presentViewController(alert, animated: true, completion: nil)
} else {
let alert2 = UIAlertController(title: "Move on", message: "Are you ready to move on?", preferredStyle: UIAlertControllerStyle.Alert)
alert2.addAction(UIAlertAction(title: "Yes", style: UIAlertActionStyle.Default, handler: { action in
self.performSegue to next screen
}))
n.addAction(UIAlertAction(title: "No", style: UIAlertActionStyle.Cancel, handler: { action in
}))
}
The code seems to be fine but i get the following error:
Attempting to load the view of a view controller while it is deallocating is not allowed and may result in undefined behavior
This seems like it should work pretty easily and a common thing to do, but there is no solution on line to this problem. Any help/guidance would be much appreciated.
you had missed to present the alert2
self.presentViewController(alert2, animated: true, completion: nil)
Add that and it will work fine.
This line is not required:
alert.dismissViewControllerAnimated(true, completion: nil)
Also add
self.presentViewController(alert, animated: true, completion: nil)
in else part.
#IBAction func addButton(sender: AnyObject) {
let alert = UIAlertController(title: "New Exercise Added", message: "\(name)", preferredStyle: UIAlertControllerStyle.Alert)
alert.addAction(UIAlertAction(title: "Ok!!", style: UIAlertActionStyle.Default, handler: nil))
self.presentViewController(alert, animated: true, completion: nil)
self.navigationController?.popToRootViewControllerAnimated(true)
self.dismissViewControllerAnimated(true, completion: {})
}
Within the IB action function of a button I have an alert, followed by some code to change to a different ViewController.
The program crashes upon reaching these lines of code after the alert:
2016-01-04 17:48:27.147 FitnessApp[60584:4080964] popToViewController:transition: called on while an existing transition or presentation is occurring; the navigation stack will not be updated.
How do I run the code to change ViewController after the transition is done?
Your biggest issue is that you don't do anything with the alert button's handler. Instead, you immediately try to do the pop and dismiss after presenting the alert.
Move the code to pop the controller into the Ok button's alert handler.
#IBAction func addButton(sender: AnyObject) {
let alert = UIAlertController(title: "New Exercise Added", message: "\(name)", preferredStyle: UIAlertControllerStyle.Alert)
alert.addAction(UIAlertAction(title: "Ok!!", style: UIAlertActionStyle.Default, handler: {
self.navigationController?.popToRootViewControllerAnimated(true)
// You only need the pop
//self.dismissViewControllerAnimated(true, completion: {})
}))
self.presentViewController(alert, animated: true, completion: nil)
}
Note: I'm not fluent in Swift so the syntax could be off a little.
I have this function and I use it on almost all viewController´s that I have, for some reason went I push "ok" to dismiss the pop up, it switches to another viewController.
this is my function...
extension UIViewController
{
func displayAlert(title: String, message: String)
{
let alert = UIAlertController(title: title, message: message, preferredStyle: UIAlertControllerStyle.Alert)
alert.addAction((UIAlertAction(title: "Ok", style: .Default, handler:
{ (action) -> Void in
self .dismissViewControllerAnimated(true, completion: nil)
})))
self.presentViewController(alert, animated: true, completion: nil)
}
}
any help? I'm using Xcode 7.0 beta 6 with swift 2
You don't need to dismiss the alert controller yourself. That happens automatically with your alert action. You're simply providing a closure that gets called when that "OK" action gets triggered. Just remove this line:
self.dismissViewControllerAnimated(true, completion: nil)