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.")