Updating Calibre metadata

[mst]

Finally seeing the light with metadata, Calibre and Koreader, many thanks to all your inputs so far!

Some quirks still baffle me. For instance, in Calibre, I added tags to epubs that are already on the device, and I'd like to update just the metadata, so I can browse by tags on KoReader with the new metadata I added in Calibre.

Via Calibre, I update the cached metadata on the device, and the calibre.metadata file on the device updates (changed size and date), but after disconnecting from USB, KoReader doesn't recognize the new tags in the books that are already on the reader, just in new books I upload that contain the same tags.

I re-start the device and KoReader, but still, new tags don't show up. In the +Menu on KoReader, I update the cached metadata of all books (took 10 minutes for 2,000 books). Then I reconnect the device via USB and mount it in Calibre. The calibre.metadata file updates (just changes date, not size). I update the metadata again in Calibre and I disconnect the device again, but KoReader still shows the old tags.

Do I need to re-upload books when I change their tags or can I just refresh a cache on the device to make KoReader see the new tags in a more quick and easy way?

[pazos]

Originally Posted by mst

Do I need to re-upload books when I change their tags or can I just refresh a cache on the device to make KoReader see the new tags in a more quick and easy way?

The "search metadata" option of the calibre plugin doesn't need to re-upload books. Each time the file calibre.metadata changes the cache gets invalidated and the new metadata is picked.

If you're talking about the metadata you see in the file manager, that's the one embedded in the epub. I have no idea if editing the properties of a book in calibre will change the metadata embedded in the epub (I barely use calibre).

If that's true you need to re-upload the books and refresh the cache. an image worth +1000 words.

If that's false you need to edit your epubs, add valid metadata, re-upload them and refresh the cache.

Also, for the future: please don't create a new thread for each question you have on the same topic. Just repurpose the original thread. It is easier to track and make the original thread more complete.

[NiLuJe]

Which part of the UI are you talking about, exactly?

* The Calibre plugin (e.g., "Find a book via calibre metadata") should pickup calibre.metadata changes immediately.

That's assuming you actually manage to get Calibre to update that properly in the first place .

IIRC, what you're doing *is* the right procedure, but I've had instances of the cache being so inconsistent that weird crap happened. When in doubt, delete the file on the device manually *without Calibre running*, then re-run Calibre and let it build it from scratch (it'll take *a while*).

* As far as the FileManager is concerned, it won't refresh anything on its own *ever*. If you tap "Refresh cached book information" in the long-press menu, it will, but that's entirely based on the ePub metadata, not Calibre's.

And, IIRC, Calibre does *not* update the on-device book when you tweak its metadata on Calibre's side, not without further intervention (e.g., re-sending it). Someone more familiar with Calibre may correct me, because that's something I extremely rarely do.

(The Calibre Kobo driver, on the other hand, probably fixes the *Nickel* metadata automatically for those, provided automatic metadata management is enabled. But that's irrelevant in KOReader ).

[mst]

Thanks for your feedback.

Which part of the UI are you talking about, exactly?

I mean the Calibre plugin. I'm past the file manager already.

I investigated this further and the strange part is this: When updating the metadata through Calibre without re-uploading any books, KoReader won't recognize the changes. Deleting and having Calibre rebuild the metadata file also has no effect. However, when I re-upload just one of the books with changed tags, then KoReader recognizes all the changes.

Works for me, but it's a little strange nonetheless. Sorry @pazos for the many threads. I think your guys' feedback cleared up all of my questions for now.

[NiLuJe]

IIRC, Calibre needs a reason to update the on-device calibre.metadata file.

Sending a book is one.

Just fiddling with the metadata in its UI isn't.

[mst]

Great, thank you! I think I figured it out now.

Do you think it makes sense for me to write up a newbie's guide to organizing books on KoReader with Calibre, or does this exist already? I think this would help new users clear the fog. Happy to do it, unless it's redundant.

[Alan_S]

Why not, write it in wiki, there it would be great help to all who wants to use it, and as you now know how to organize this, it would be a great plus.

[JSWolf]

A lot of eBooks have rubbish in the OPF including worthless tags. They need to be edited so the metadata in the OPF is correct.

[pazos]

Originally Posted by mst

Great, thank you! I think I figured it out now.

Do you think it makes sense for me to write up a newbie's guide to organizing books on KoReader with Calibre, or does this exist already? I think this would help new users clear the fog. Happy to do it, unless it's redundant.

Guides are great as a resource and can help newbies with specific workflows. Any guide is welcome no matter how specific the workflow is and how the writter approached its target. It has the status as "works for me" and indeed can works for others too.

For the wiki the expectations are different. From the README in github:

document lesser-known features on the wiki

So it depends on the approach. There's a wiki page for the calibre plugin that doesn't cover the metadata search (because it wasn't part of the plugin until recently)

In wiki pages it is better to document what can be done with the plugin.

Elsewhere you can use a more natural language and document what you want any way you want, without too much restriction.

See, for instance, https://medium.com/@candide.uyanze/h...e-f727f04e197d

It is a valid workflow for the author but very difficult to translate to wiki pages. It is also not the only specific way of getting that done.

So, to sum up:

1. All contributions are welcome.

2. The wiki is expected to document features and use specific bits as examples. You're welcome to write a guide using a new wiki page and adds link where you see it fits. Keep in mind that the wiki is a moving target and any workflow you wrote can be rewritten by somebody else in a way that matches better their needs.

3. There's other places on the web to write these guides, keep autorship and prevent others from modifying your workflow in a way you don't agree with.

tl;dr: All contributions are welcome.

[ezuk]

Hi there,

I apologize for reviving this thread, but looking at the wiki, I don't see that it's been updated and I seem to be running up against the same issue. Specifically:

1) I have a library of around 800 books in Calibre, which I synced into my KOReader instance.
2) This library has many tags. Upon initial sync, the tags moved to KOReader perfectly, and I was able to browse my library by tag. This was immensely useful.
3) I then went and edited some tags: Removed books that were incorrectly tagged, added books to a tag.
4) I plugged KOReader into Calibre again, and selected "Device -> Update metadata on device".
5) The KOReader tags were then completely nuked. The books are still there, but the tags now show up entirely empty on the device.

I tried recopying one book over (the file was already on the device but I sent it again just in case), at which point the tags for this one book appeared.

So I'm clearly missing something: How can I refine my tag data in Calibre, and then reflect those changes in KOReader?

Many thanks.

[NiLuJe]

On which device is that? And how are the books transferred?

[ezuk]

This is on a Kobo Libra H2O. The books were transfered via the WiFi client, and then via USB cable when that did not work.

In case it is relevant: When connecting via WiFi, Calibre reports a subset of books as in-memory on device. When connecting via USB, Calibre reports a different subset of books as in-memory. In reality, there is only one directory with books on device.

The host is running Calibre 6.8 on macOS 12.6.

[NiLuJe]

That is your problem. You can't mix'n match calibre drivers in the same "target" (i.e., on device) root library (if you hope to keep a consistent on-device calibre metadata state, that is. if you just want to shove books somewhere, that's fine ).

Which means that, unless everything is setup in a specific, per-driver directory tree, you can't mix'n match calibre Wireless with Send to Device via the Kobo Driver (and, to a lesser extent, care has to be taken when using the Kobo driver over USB from both KOReader's USBMS tool and Nickel, as the Kobo driver relies on Nickel's DB, and uses it as a source of truth, while we never touch it at all; I've written about this in the past here). The calibre Wireless plugin should have shouted very sternly at you if you tried to setup a library inbox in a folder already handled by a different calibre driver.

Everything needs to live in its own island (which is why you effectively see different "on device" status in calibre depending on how you connect), otherwise you utterly mangle the consistency of the on-device calibre metadata cache.

[ezuk]

Thank you very much, NiLuJe — that does explain it! The wireless plugin did not say anything when I set up the home folder as an inbox, but I will now stick to a single sync modality. I appreciate your time!