Create an Nsalert with Swift

Create an NSAlert with Swift

beginSheetModalForWindow:modalDelegate is deprecated in OS X 10.10 Yosemite.

Swift 2

func dialogOKCancel(question: String, text: String) -> Bool {
    let alert: NSAlert = NSAlert()
    alert.messageText = question
    alert.informativeText = text
    alert.alertStyle = NSAlertStyle.WarningAlertStyle
    alert.addButtonWithTitle("OK")
    alert.addButtonWithTitle("Cancel")
    let res = alert.runModal()
    if res == NSAlertFirstButtonReturn {
        return true
    }
    return false
}

let answer = dialogOKCancel("Ok?", text: "Choose your answer.")

This returns true or false according to the user's choice.

NSAlertFirstButtonReturn represents the first button added to the dialog, here the "OK" one.

Swift 3

func dialogOKCancel(question: String, text: String) -> Bool {
    let alert = NSAlert()
    alert.messageText = question
    alert.informativeText = text
    alert.alertStyle = NSAlertStyle.warning
    alert.addButton(withTitle: "OK")
    alert.addButton(withTitle: "Cancel")
    return alert.runModal() == NSAlertFirstButtonReturn
}

let answer = dialogOKCancel(question: "Ok?", text: "Choose your answer.")

Swift 4

We now use enums for the alert's style and the button selection.

func dialogOKCancel(question: String, text: String) -> Bool {
    let alert = NSAlert()
    alert.messageText = question
    alert.informativeText = text
    alert.alertStyle = .warning
    alert.addButton(withTitle: "OK")
    alert.addButton(withTitle: "Cancel")
    return alert.runModal() == .alertFirstButtonReturn
}

let answer = dialogOKCancel(question: "Ok?", text: "Choose your answer.")

How do I write an NSAlert in latest swift?

You should run your code from viewDidAppear because your view controller has not created a window object in viewDidLoad.

override func viewDidAppear() {
    super.viewDidAppear()

    alertUser()
}

When creating an NSAlert in Objective C, will I need to release the NSAlert?

If you have ARC enabled (which has been the default for new projects for years), then you don't need to release the NSAlert. In fact the code will not compile if you try to, because you are not allowed to send the release message when ARC is enabled.

If you have ARC disabled, then yes, you should [alert release] after you [alert runModal]. You need to release because you became an owner of it when you sent the alloc message.

Read more in “Memory-Management Rules” in the Cocoa Core Competencies guide.

If your project already contains Swift code, then there is no particular reason to use Objective-C instead of Swift to create this alert.

If your project doesn't already contain Swift code, then adding your first Swift code to the project may increase your compile times more than you want. Objective-C typically compiles much faster than Swift.

NSAlert destructive button

Set the property hasDestructiveAction of the button to true . This property is new in Big Sur.

Source: AppKit Release Notes for macOS Big Sur 11

Swift: How to make NSTextField first responder in NSAlert

Instead of makeFirstResponder, use this:

alert.window.initialFirstResponder = passField

How to ensure NSAlert pop up on window top?

I found an answer to my own question:

alert.window.level = .floating

This works.

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