A number containing a Boolean value that determines if validation and error alert panels displayed as a result of this binding are displayed as application modal alerts.
true, then the alerts are displayed application model, otherwise they are displayed as sheets.
static let continuouslyUpdatesValue: NSBindingOption
NSNumber object containing a Boolean value that determines whether the value of the binding is updated as edits are made to the user interface item or is updated only when the user interface item resigns as the responder.
static let raisesForNotApplicableKeys: NSBindingOption
NSNumber object containing a Boolean value that specifies if an exception is raised when the binding is bound to a key that is not applicable—for example when an object is not key-value coding compliant for a key.