These docs are for an old release.
Info on upgrading to v4
viewDestroy
Triggered when a rendered date-range needs to be torn down.
function( view, element )
view is the View Object for the view that is about to be destroyed.
element is a jQuery element for the container of the view.
This callback will be triggered immediately before the view is about to be removed from the DOM. This could happen because of a view type switch, a date range change, or a destroy method call.