Crear una NSAlert con Swift

cocoa

Question

Tengo el código para crear y NSAlert en Objective-C, pero ahora me gustaría crearlo en Swift.

La alerta es para confirmar que el usuario desea eliminar un documento.

Me gustaría que el botón "eliminar" ejecute la función de eliminación y el botón "cancelar" solo para descartar la alerta.

¿Cómo puedo escribir esto en Swift?

    NSAlert *alert = [[[NSAlert alloc] init] autorelease];
    [alert addButtonWithTitle:@"Delete"];
    [alert addButtonWithTitle:@"Cancel"];
    [alert setMessageText:@"Delete the document?"];
    [alert setInformativeText:@"Are you sure you would like to delete the document?"];
    [alert setAlertStyle:NSWarningAlertStyle];
    [alert beginSheetModalForWindow:[self window] modalDelegate:self didEndSelector:@selector(alertDidEnd:returnCode:contextInfo:) contextInfo:nil];

Answer 1

Actualizada la respuesta de José Hidalgo para Swift 4:

let a: NSAlert = NSAlert()
a.messageText = "Delete the document?"
a.informativeText = "Are you sure you would like to delete the document?"
a.addButton(withTitle: "Delete")
a.addButton(withTitle: "Cancel")
a.alertStyle = NSAlert.Style.warning

a.beginSheetModal(for: self.window!, completionHandler: { (modalResponse: NSApplication.ModalResponse) -> Void in
    if(modalResponse == NSApplication.ModalResponse.alertFirstButtonReturn){
        print("Document deleted")
    }
})

Answer 2

Creo que esto puede funcionar para ti ...

    let a = NSAlert()
    a.messageText = "Delete the document?"
    a.informativeText = "Are you sure you would like to delete the document?"
    a.addButtonWithTitle("Delete")
    a.addButtonWithTitle("Cancel")
    a.alertStyle = NSAlertStyle.WarningAlertStyle

    a.beginSheetModalForWindow(self.view.window!, completionHandler: { (modalResponse) -> Void in
        if modalResponse == NSAlertFirstButtonReturn {
            print("Document deleted")
        }
    })

Answer 3

beginSheetModalForWindow:modalDelegate está en desuso en 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.")

Esto devuelve true o false según la elección del usuario.

NSAlertFirstButtonReturn representa el primer botón agregado al diálogo, aquí el "OK".

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

Ahora usamos enumeraciones para el estilo de la alerta y la selección del botón.

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.")