The button label. Will be localized.
FontAwesome icon classes.
CSS classes to apply to the button.
Whether this button represents the default action to take if the user submits the form without pressing a button, i.e. with an Enter keypress.
A function to invoke when the button is clicked. The value returned from this function will be used as the dialog's submitted value. Otherwise, the button's identifier is used.
The button action identifier.