'Renders the Studio preview view, which supports drag and drop.'

def author_view(self, context):

    fragment = Fragment()
    root_xblock = context.get('root_xblock')
    is_root = (root_xblock and (root_xblock.location == self.location))
    if (is_root or (not context.get('is_unit_page'))):
        self.render_children(context, fragment, can_reorder=True, can_add=True)
    return fragment
