Where to find a clear explanation about swift alert (UIAlertController)?

Question

Couldn't find a clear and informative explanation for this.

Answer 1

After searching a while on a subject I didn't find a clear explanation , even in it's class reference UIAlertController Reference

It is ok, but not clear enough for me.

So after collecting some peaces I decided to make my own explanation (Hope it helps)

So here it goes:

1. UIAlertView is deprecated as pointed out : UIAlertView in Swift
2. UIAlertController should be used in iOS8+ so to create one first we need to instantiate it, the Constructor(init) gets 3 parameters:

2.1 title:String -> big-bold text to display on the top of alert's dialog box

2.2 message:String -> smaller text (pretty much explains it's self)

2.3 prefferedStyle:UIAlertControllerStyle -> define the dialog box style, in most cases: UIAlertControllerStyle.Alert

3. Now to actually show it to the user, we can use showViewController or presentViewController and pass our alert as parameter

4. To add some interaction with a user we can use:

4.1 UIAlertController.addAction to create buttons

4.2 UIAlertController.addTextField to create text fields

Edit note: code examples below, updated for swift 3 syntax

Example 1: Simple Dialog

@IBAction func alert1(sender: UIButton) {      //simple alert dialog     let alert=UIAlertController(title: "Alert 1", message: "One has won", preferredStyle: UIAlertControllerStyle.alert);     //show it     show(alert, sender: self); } 

Example 2: Dialog with one input textField & two buttons

@IBAction func alert2(sender: UIButton) {     //Dialog with one input textField & two buttons     let alert=UIAlertController(title: "Alert 2", message: "Two will win too", preferredStyle: UIAlertControllerStyle.alert);     //default input textField (no configuration...)     alert.addTextField(configurationHandler: nil);     //no event handler (just close dialog box)     alert.addAction(UIAlertAction(title: "No", style: UIAlertActionStyle.cancel, handler: nil));     //event handler with closure     alert.addAction(UIAlertAction(title: "Yes", style: UIAlertActionStyle.default, handler: {(action:UIAlertAction) in         let fields = alert.textFields!;         print("Yes we can: "+fields[0].text!);     }));     present(alert, animated: true, completion: nil); } 

Example 3: One customized input textField & one button

@IBAction func alert3(sender: UIButton) {    // one input & one button    let alert=UIAlertController(title: "Alert 3", message: "Three will set me free", preferredStyle: UIAlertControllerStyle.alert);      //configured input textField     var field:UITextField?;// operator ? because it's been initialized later     alert.addTextField(configurationHandler:{(input:UITextField)in         input.placeholder="I am displayed, when there is no value ;-)";         input.clearButtonMode=UITextFieldViewMode.whileEditing;         field=input;//assign to outside variable(for later reference)     });     //alert3 yesHandler -> defined in the same scope with alert, and passed as event handler later     func yesHandler(actionTarget: UIAlertAction){         print("YES -> !!");         //print text from 'field' which refer to relevant input now         print(field!.text!);//operator ! because it's Optional here     }     //event handler with predefined function     alert.addAction(UIAlertAction(title: "Yes", style: UIAlertActionStyle.default, handler: yesHandler));      present(alert, animated: true, completion: nil);  } 

Hope It helps, and good luck ;-)