Well i played a little bit with the "if, then, else" in a template.
Code:
:if:{series}:then:{series│_│}:else:{first_author}:::/{series_index││ - }{title} - {first_author}
Downloading books from Dropbox:
Result for Books with series as expected.
_Series/1 - Title - First Author
Result for books without series as expected:
First Author/Title - First Author
So far so good.
If there would be the possibility to define the amount of digits (so that files get correct listed in case there are more than 10 books in a series) in "series_index" i would be more than happy..jaja.
I love it.
Looking forward to Calibre 2.32, so that CC can take his template when books are pushed from Calibre to CC with Wifi.