Missing author substitution ('Unknown') handling in other languages

[wold]

Hi, when a file (epub, etc) misses an author field, Calibre substitutes the missing value with "Unknown".
This value is stored as such in the database.

1) How is this database entry handled for non-english languages?
For, say, German locale, is the database value also stored as "Unknown" and afterwards translated using gettext for the GUI?
Or is it stored as "Unbekannt" and never translated?

The context is dealing with an external device DB, where authors can be NULL.

[kovidgoyal]

The calibre database is normalised. So author values are not stored directly on book records, instead there is a separate authors table and a link table to join it with the books table. Unknown authors are never stored in the authors table as far as I remember.

[BetterRed]

Originally Posted by kovidgoyal

The calibre database is normalised. So author values are not stored directly on book records, instead there is a separate authors table and a link table to join it with the books table. Unknown authors are never stored in the authors table as far as I remember.

@kovid - FWIW the "Unknown" author is stored in the authors table:



And the books_author_table associates books with the "Unknown" author



It's also in the author_sort column of the books table


In case I'd done something strange with my Test library, I also checked my Books library - it's the same.

Moderator Notice
@wold - Moved out of Development. See the sticky at top of that sub-forum.

BR

[kovidgoyal]

Ah well then I am misremembering.

[wold]

Thanks. Confirmed this in part (sorry): other locales do store their own translation.
What mattered in that case is the follow-up question:

2) to retrieve the "Unknown" equivalent for other locales, could one use gettext substitution, like below?

authorname = _("Unknown")

To be honest, this seems best avoided, but knowing it can be done, etc.

[chaley]

I switched my language to French then added a new empty book. I was offered the author name "Inconnu(e)". After adding the book that author appeared in the authors table. I draw from this test that there is no constant name for an unknown author. It depends on calibre's language when the name was used, for example when adding books.

I could add a template function that returns the value of an (English) string in the current language locale, but I am not yet convinced that it would be useful.

[kovidgoyal]

Yes _('Unknown') will give you the value of an unknown author in the current interface language.

[ownedbycats]

@chaley - just curious, did Authors: Inconnu(e) appear in the Book Details? In English, that line will disappear.

[wold]

Originally Posted by Chaley

I could add a template function that returns the value of an (English) string in the current language locale, but I am not yet convinced that it would be useful.

Thanks, but no need for it yet. I'll also explore the mentioned gettext route.

To clarify, this involved matching 'exotic formats' on the device with calibre. The device uses the filename as title. However, given calibre appends the author to the filename, it can't be easily matched back to calibre's title. Regex substitution works, but I forgot about localization of 'Unknown'. For now the part is removed, as it's not vital.

This also concerns possible future utils. Not wanting to get stuck at 99%.

[chaley]

Originally Posted by ownedbycats

@chaley - just curious, did Authors: Inconnu(e) appear in the Book Details? In English, that line will disappear.

When the language is French, "Inconnu(e)" doesn't appear but "Unknown" does. The opposite happens when the language is English.