document.edoc.getroot().set('data-cover-by', document.book_info.cover_by)
if document.book_info.cover_source:
document.edoc.getroot().set('data-cover-source', document.book_info.cover_source)
document.edoc.getroot().set('data-cover-by', document.book_info.cover_by)
if document.book_info.cover_source:
document.edoc.getroot().set('data-cover-source', document.book_info.cover_source)