tags

[cybmole]

my main question is here in calibre forum:
https://www.mobileread.com/forums/sho...91#post2957091

this is a supplementary.

when I download a book, CC shows me what tags it found in calibre metadata.

it does not tell me about tags lurking within <dc:subject elements of opf, which also appear as tags when I import the book to mantano

mantano treats entries like these as tags:
<dc:subject>Science Fiction</dc:subject>
<dc:subject>Short Fiction</dc:subject>
<dc:subject>Fantasy</dc:subject>
<dc:subject>Suspense</dc:subject>
<dc:subject>Thriller</dc:subject>
<dc:subject>Mystery</dc:subject>
<dc:subject>Adventure</dc:subject>

but I've not tested other reader apps. is it wrong for Mantano to show these as tags, & if the answer to that is NO then is is right for CC to NOT show them as tags.

what mantano is doing may actually be more complex.. When a book has tags within calibre/ within CC , they seem to appear correctly in mantano, without having been written into the epub opf, The books that go "wrong", in my limited testing, are books with no tags in calibre / CC - mantano seems to then use the dc subject data, rather than show "no tags". I have not yet seen a combination of the calibre tags AND the dc subject tags show up in mantano bookshelves

I am a tad confused, as to what is supposed to be best practice here , but I suspect that other folks understand this well & there's no need for me to be testing all sorts of download routes/apps combos ?

i did test & observe that if I use save to disc then calibre updates the tags in those dc fields with it's own data. I guess ideally it would be good if that also happened when CC downloaded a book from the content server?
I have not checked what CC does with tags when book is moved via the wireless device route.

[kaufman]

The link doesn't work.

[chaley]

CC's contract with you is that it will show the metadata (tags) defined in calibre as of the time CC's metadata for the book was last updated. This time is the later of when it was fetched from the content server, when it was sent over a wireless device connection, or the last connect as a wireless device where updating metadata completed successfully.

CC has no control over what Mantano does or does not do. Nor does CC use metadata stuffed into the book format, such as the OPF inside an epub. Whether or not a book's metadata is updated when it leaves calibre depends on a host of things, such as what format it is, how it is being sent, and whether it has DRM. This is the major reason that CC pays no attention at all to embedded metadata. There isn't much reason to believe that it is correct, where "correct" means equal to the metadata in calibre at the moment the book arrives on the device.

Note: fetching from dropbox will not update metadata inside a book.

[cybmole]

I think there's a bug in content server, but only in the case where a book has no calibre tags. in that instance, calibre is not stripping out any original tags. the proof of that is that mantano is finding them, after the book has travelled via content server to CC and onwards. I have posted reproducible detail in the main calibre thread. Add a single "test" tag in calibre to the same book & it travels oK, Mantano sees "test", & nothing else.


sorry about the link not working, I did a simple copy & paste?
here's a retry
https://www.mobileread.com/forums/sho...39#post2957639

[chaley]

Originally Posted by cybmole

I think there's a bug in content server, but only in the case where a book has no calibre tags.

Could be, although it might be intentional. My guess is that you (someone) will end up needed to file a calibre bug report.

[cybmole]

Originally Posted by chaley

Could be, although it might be intentional. My guess is that you (someone) will end up needed to file a calibre bug report.

yes. I'm hoping that someone will test & confirm- or not- what I'm seeing , before filing any reports.

in the meantime , it is very easy to edit the tags that mantano shows, if I'm feeling obsessive

PS where does CC put the tags etc that it gets from calibre. I know where it puts the epubs but is there another storage area/database on the tablet ?
Does CC receive an opf file from content server and then incorporate data from that into it's own storage ?

[chaley]

Originally Posted by cybmole

PS where does CC put the tags etc that it gets from calibre. I know where it puts the epubs but is there another storage area/database on the tablet ?
Does CC receive an opf file from content server and then incorporate data from that into it's own storage ?

The tags are stored in CC's database, both as they originally came from calibre and as processed for the grouping drawer.

CC does not receive or use an OPF. Instead it receives a copy of the metadata in an internal format that accurately reflects what is in calibre's database. It receives this internal format via both the WD connection and the content server. For the wireless device, this special format is the "native" one used by calibre since we added it for Sonys way back in 2010. I modified the content server during CC's development to add the necessary connections for CC to get the info in that format.

[cybmole]

thanks for that.

I can mentally constuct one scenario that could exonerate content server:
IF Mantano database still retains some data even after a book is deleted in Mantano, AND if the book in question was once fetched from dropbox not via CC, then maybe I'm seeing old tags been retreived and redisplayed. I don't think that is the case(*) but I need to go find book(s) that have never been on the tablet and that have internal tags only, then move those via CC & see what happens.

(*) because I added a tag called "test" to that book in calibre, re-sent it via CC - it appeared with "test" in the mantano tags - thus mantano was updating, then I removed the book from tablet & removed the test tag in calibre - re-sent it again, and the old mystery, suspense... tags re-appeared.

[cybmole]

update- well I have established that I can reproduce an effect.
I took a book with no calibre tags that has never been on my tablet.
using sigil I edited its content.opf and added <dc:subject>mytag</dc:subject>.
then saved the book, moved it via CC & content server, saw mytag in mantano but not in CC
so content server is NOT removing the tag.
CC IS reflecting what I see in Calibre,as it should.

next question is: is that a bug or a feature. it does seem inconsistent with save to disc and with modify epub, as they do remove it.

maybe I should move this to main calibre thread, I don't know how to test content server output without using tablet though.

[chaley]

Given that this has nothing to do with CC, I do think you should carry on the discussion on the calibre thread. My guess is that Kovid will need to answer and he doesn't hang out here.