Detecting Safari 'Reader Mode'

is there any way to detect if Safari is going to interpret my js/html as something it should open in its "Reader View" I have a built-in ebook reader and other views that safari chooses to open in the reader view. Is there any api for that? Also with safari 11 the user can default to open all eligible pages in reader view. Is there any way to detect if a user has that setting selected?