How to create and get return Value from Cocoa Dialog?

Question

In my application, I want to create a dialog box with one text field, and a button, through which I can prompt user and get back user entered value.

How do I do this

Answer 1

An example in Swift as of Xcode 7.2.1 and OS X 10.11:

let a = NSAlert()
a.messageText = "Please enter a value"
a.addButtonWithTitle("Save")
a.addButtonWithTitle("Cancel")

let inputTextField = NSTextField(frame: NSRect(x: 0, y: 0, width: 300, height: 24))
inputTextField.placeholderString = "Enter string"
a.accessoryView = inputTextField

a.beginSheetModalForWindow(self.window!, completionHandler: { (modalResponse) -> Void in
    if modalResponse == NSAlertFirstButtonReturn {
        let enteredString = inputTextField.stringValue
        print("Entered string = \"\(enteredString)\"")
    }
})