[davidfor]

Originally Posted by Agama

The ID's should be able to be generated automatically, (they also exist at the heading and paragraph levels), since they have systematic numbering. The <style id="kobostylehacks" ...> and javascript would need to be generated, (or linked in from some predefined static data). I don't know if these dependent parts vary between kepubs.

Yes, generating the ids could be done, and it probably wouldn't be hard. As to the other buts, I don't know if they are the same of change. At the least, I would expect them to change over time as they fine-tune the display.

I wonder how much interest there would actually be in producing kepubs from other formats? Maybe it would be possible to store kepubs in calibre and only allow conversion to other formats, send-to-device, save-to-disc etc, but no conversion from other formats to kepub.

Outside of the Kobo device users, none. But, there is some interest for Kobo users. Apart from the syncing, kepubs use a different renderer on the devices. The fonts are handled a little differently, but the main thing people comment on is the page numbering. For both types, the device shows a "Page x of y" at the bottom of the screen. For epubs, the "y" is the pages in the book. But for kepubs, the "y" is the page in the current chapter. Some people love this. Others hate it.

On the Kobo devices, you can get the kepub renderer to open a normal epub by using the double extension ".kepub.epub". It seems to work for everything except the syncing, though I don't know if there is a problem with bookmarks and highlights. When this was discussed, a Kobo developer warned against it, but I think it was mainly because the syncing didn't work.

Adding the ability to import kepubs into calibre is probably a good idea. Then allowing the conversion of the non-DRMed books to other formats. One issue is the file name I mentioned before. I'd have to see about not losing this. It will go on my todo list, but not at a high priority. I haven't been into that part of the calibre code much, so I don't know it. Also, as the books can be obtained from Kobo in epub format, that gives a alternative method to achieve the same thing.

I'm still interested in seeing why the OP's kepub gave an error on adding to calibre. This seems to suggest it must be different in some way to the one I've had a play with.

No, its because I told calibre to say that. Or at least I told the driver to tell calibre. As calibre doesn't know what a kepub is, they are on the don't import list. When you try, calibre displays this message.