code: def can_mark_block_complete_on_view(self, block):
          
          return (
              XBlockCompletionMode.get_mode(block) == XBlockCompletionMode.COMPLETABLE
              and not getattr(block, 'has_custom_completion', False)
              and not getattr(block, 'has_score', False)
          )
docs: Returns True if the xblock can be marked complete on view.
          This is true of any non-customized, non-scorable, completable block.