[GUI Plugin] Modify ePub

[foosion]

Originally Posted by theducks

It is a Calibre Tweak
ID: save_original_format

When calibre does a conversion from the same format to the same format, for example, from EPUB to EPUB, the original file is saved, so that in case the conversion is poor, you can tweak the settings and run it again. By setting this to False you can prevent calibre from saving the original file. Similarly, by setting save_original_format_when_polishing to False you can prevent calibre from saving the original file when polishing.

Setting both to False worked.

[DNSB]

I think I've complained about the before but when Remove non-DC metadata elements is checked, the DC Modified item is removed. It is the only mandatory for ePub3 property that does not start with <dc: but it's an annoyance having to restore it.

<meta property="dcterms:modified">2025-03-23T18:40:12Z</meta>

[kiwidude]

Originally Posted by DNSB

I think I've complained about the before but when Remove non-DC metadata elements is checked, the DC Modified item is removed. It is the only mandatory for ePub3 property that does not start with <dc: but it's an annoyance having to restore it.

<meta property="dcterms:modified">2025-03-23T18:40:12Z</meta>

This isn't a plugin I use personally beyond a couple of most basic features once in a blue moon, and certainly not a niche feature intended for book publishers like this one.

Obviously ePub3 didn't exist back in 2011 when this plugin feature was written. To change this will require not just a change in this plugin, but also a change to the Quality Check plugin to make it skip this attribute.

It shouldn't be a majorly difficult change (I hope), will put it on the list.

[kiwidude]

Release Notes
https://github.com/kiwidude68/calibr...fy_epub-v1.8.6

I still need to make the matching change to Quality Check later...

[DNSB]

Originally Posted by kiwidude

This isn't a plugin I use personally beyond a couple of most basic features once in a blue moon, and certainly not a niche feature intended for book publishers like this one.

Obviously ePub3 didn't exist back in 2011 when this plugin feature was written. To change this will require not just a change in this plugin, but also a change to the Quality Check plugin to make it skip this attribute.

It shouldn't be a majorly difficult change (I hope), will put it on the list.

I've been using that feature to remove the mass of useless information that some self-published epubs seem to have—an .opf file that runs over 3000 lines is ridiculous. Sigil and calibre's ebook-editor will fix that issue automatically by inserting a line with the current modified date but I would prefer to maintain the original modified date.

Thanks for the change!

[DNSB]

Got around to doing more testing with the updated plugin and it spits out an error message when I attempt to modify more that one file at a time. My test was with 3 files and got the error message after clicking Yes to replace the versions in the library (the log file prior to clicking yes did not show any errors). Doing those 3 files one at a time did not generate the error message.

calibre, version 8.0.1
ERROR: Unhandled exception: <b>AttributeError</b>:'NoneType' object has no attribute 'update_last_modified'
...
Traceback (most recent call last):
  File "calibre_plugins.modify_epub.dialogs", line 291, in do_book_check
  File "calibre_plugins.modify_epub.dialogs", line 310, in do_close
AttributeError: 'NoneType' object has no attribute 'update_last_modified'

[kiwidude]

@DNSB - that isn't something I have been able to replicate, nor does it look in any way related to the change I made. That error message looks like somehow the plugin dialog has been unable to find the current database object. TBH I haven't even seen the prompt for so long (I have it turned off in configuration options for that plugin), but I selected 3 books, did an add/replace cover, and it all worked fine.

Is it only on specific Modify ePub options being ticked? In which case there must be more error messages or log somewhere, PM me the full log.

[DNSB]

Getting rather weird. It only happened on my Intake library. So I created a new library copying the structure of the Intake library and copied the contents of my Intake library there. After the copy, I could happily Modify ePub the contents of Intake2 without getting the error message after clicking on yes. I then deleted the original Intake library, created a new one after deleting the contents of the Intake directory, copied everything back from the Intake2 library and no issues running Modify ePub.

When I was playing with my original Intake library after moving the contents to Intake2, I copied 5 files from my Main library and they came up with the same error message. So something in the library or it's structure caused the issue but, as the old sign I had above my desk at work said, We don't believe in miracles, we just depend on them.

I've attached my Modify ePub configuratin screen and the calibre debug error logs. Once again, thanks for your help and feedback.