Why are the buttons on my UIAlert duplicating? - swift

Question

I'm attempting to build an app using Swift that's similar to the Notes app, but I'd like to have an Alert pop up when the user presses the "+" button to add a new Note - and the Alert would prompt the user to enter a name. The name is then added as a new row in the underlying table. So far, I've been able to do this, but every time i click the "+" sign, the buttons I've added to the Alert get re-added. In other words, the Alert should have an "OK" & a "Cancel" button. But on the 2nd time the Alert pops up, there are 2 "OK" buttons, and 2 "Cancel" buttons, and so on. Any ideas how i can fix this? Thanks for your help!
class ViewController: UIViewController, UITableViewDataSource, UITableViewDelegate {
#IBOutlet weak var table: UITableView!
var data:[String] = []
//create alert controller
var alert = UIAlertController(title: "Name", message: "Enter a name", preferredStyle: .alert)
override func viewDidLoad() {
super.viewDidLoad()
// Do any additional setup after loading the view, typically from a nib.
self.title = "Notes"
//create "add" button
let addButton = UIBarButtonItem(barButtonSystemItem: .add, target: self, action: #selector(addAlert))
self.navigationItem.rightBarButtonItem = addButton
//create edit button so we can delete rows
self.navigationItem.leftBarButtonItem = editButtonItem
load()
}
//function to add new note. This code is executed when the "Add" button is clicked
func addNote()
{
//code to prevent being able to add rows while in edit mode
if (table.isEditing) {
return
}
let textField = self.alert.textFields![0] as UITextField
let name:String = textField.text!
data.insert(name, at: 0)
let indexPath:IndexPath = IndexPath(row: 0, section: 0)
table.insertRows(at: [indexPath], with: .automatic)
save()
}
func addAlert()
{
alert.addTextField(configurationHandler: { (textField) -> Void in
textField.placeholder = "Enter Name"})
self.present(alert, animated: true, completion: nil)
//grab value from the text field and print when user clicks OK
alert.addAction(UIAlertAction(title: "OK", style: .default, handler: { (UIAlertAction) in
let textField = self.alert.textFields![0] as UITextField
print("Text Field: \(textField.text!)")
self.addNote()
}))
}
func tableView(_ tableView: UITableView, numberOfRowsInSection section: Int) -> Int {
return data.count
}
func tableView(_ tableView: UITableView, cellForRowAt indexPath: IndexPath) -> UITableViewCell {
let cell:UITableViewCell = tableView.dequeueReusableCell(withIdentifier: "cell")!
cell.textLabel?.text = data[indexPath.row]
return cell
}
override func setEditing(_ editing: Bool, animated: Bool) {
super.setEditing(editing, animated: animated)
//puts table in edit mode
table.setEditing(editing, animated: animated)
}
//function to delete rows from table
func tableView(_ tableView: UITableView, commit editingStyle: UITableViewCellEditingStyle, forRowAt indexPath: IndexPath) {
data.remove(at: indexPath.row)
table.deleteRows(at: [indexPath], with: .fade)
save()
}
func tableView(_ tableView: UITableView, didSelectRowAt indexPath: IndexPath) {
self.performSegue(withIdentifier: "detail", sender: nil)
}
func save()
{
UserDefaults.standard.set(data, forKey: "notes")
UserDefaults.standard.synchronize()
}
func load()
{
if let loadedData = UserDefaults.standard.value(forKey: "notes") as? [String]
{
data = loadedData
table.reloadData()
}
}

Answer 1

Put alert.addAction before presenting the alert. Try this code in addAlert() method
func addAlert()
{
var alert = UIAlertController(title: "Name", message: "Enter a name", preferredStyle: .alert)
alert.addTextField(configurationHandler: { (textField) -> Void in
textField.placeholder = "Enter Name"})
alert.addAction(UIAlertAction(title: "OK", style: .default, handler: { (UIAlertAction) in
let textField = self.alert.textFields![0] as UITextField
print("Text Field: \(textField.text!)")
self.addNote()
}))
self.present(alert, animated: true, completion: nil)
}

Answer 2

You have to present the alert only after adding the actions(Buttons).
func addAlert()
{
alert.addTextField(configurationHandler: { (textField) -> Void in
textField.placeholder = "Enter Name"})
//grab value from the text field and print when user clicks OK
alert.addAction(UIAlertAction(title: "OK", style: .default, handler: { (UIAlertAction) in
let textField = self.alert.textFields![0] as UITextField
print("Text Field: \(textField.text!)")
self.addNote()
}))
self.present(alert, animated: true, completion: nil)
}