[GUI Plugin] Modify ePub

[enuddleyarbl]

In my situation, that titlepage.xhtml is the Cover page that Calibre produces. Jacket.xhtml is the jacket Calibre produces (probably as a result of the "Insert Metadata as Page at Start of Book" option under Structure Detection) and sticks in there (usually immediately after the titlepage.xhtml (i.e. in the 2nd position). Tpage.xhtml is actually a title page (usually, the book has it and I just rename it to that). Since that jacket is a Calibre product (which I like and use), it probably doesn't have a standard position. But, almost always, it's in that second position.

The issue I'm having is that for a very small number of books, Modify ePub just keeps putting it in 3rd position and I can't figure out why. AFAICT, in those "Miscellaneous" files, "jacket" shows up only in the .opf file (two locations: manifest (which is unordered) and spine (which is ordered)). In the problematic books, it doesn't matter where the jacket entry is (or where I drag the file in the File Browser). The plugin just moves it to the 3rd position without any obvious instruction to do so.

[enuddleyarbl]

I've attached a scrambled version of one of those books (Naomi Novik's "A Deadly Education"):

https://www.kobo.com/us/en/ebook/a-deadly-education-2

[JSWolf]

Originally Posted by enuddleyarbl

In my situation, that titlepage.xhtml is the Cover page that Calibre produces. Jacket.xhtml is the jacket Calibre produces (probably as a result of the "Insert Metadata as Page at Start of Book" option under Structure Detection) and sticks in there (usually immediately after the titlepage.xhtml (i.e. in the 2nd position). Tpage.xhtml is actually a title page (usually, the book has it and I just rename it to that). Since that jacket is a Calibre product (which I like and use), it probably doesn't have a standard position. But, almost always, it's in that second position.

The issue I'm having is that for a very small number of books, Modify ePub just keeps putting it in 3rd position and I can't figure out why. AFAICT, in those "Miscellaneous" files, "jacket" shows up only in the .opf file (two locations: manifest (which is unordered) and spine (which is ordered)). In the problematic books, it doesn't matter where the jacket entry is (or where I drag the file in the File Browser). The plugin just moves it to the 3rd position without any obvious instruction to do so.

Then you are missing the titlepage. What did you do with the titlepage?

[JSWolf]

Originally Posted by enuddleyarbl

In my situation, that titlepage.xhtml is the Cover page that Calibre produces. Jacket.xhtml is the jacket Calibre produces (probably as a result of the "Insert Metadata as Page at Start of Book" option under Structure Detection) and sticks in there (usually immediately after the titlepage.xhtml (i.e. in the 2nd position). Tpage.xhtml is actually a title page (usually, the book has it and I just rename it to that). Since that jacket is a Calibre product (which I like and use), it probably doesn't have a standard position. But, almost always, it's in that second position.

The issue I'm having is that for a very small number of books, Modify ePub just keeps putting it in 3rd position and I can't figure out why. AFAICT, in those "Miscellaneous" files, "jacket" shows up only in the .opf file (two locations: manifest (which is unordered) and spine (which is ordered)). In the problematic books, it doesn't matter where the jacket entry is (or where I drag the file in the File Browser). The plugin just moves it to the 3rd position without any obvious instruction to do so.

The reasoning is Cover, titlepage, jacket.

[enuddleyarbl]

Where is that order being set in the book?

[JSWolf]

Originally Posted by enuddleyarbl

Where is that order being set in the book?

In the spine section of the OPF.

[enuddleyarbl]

Except if I change the order in the spine so the jacket is in the 2nd position, Modify ePub puts it back (in some books) to the 3rd position. In most books, though, it'll put the jacket back into the 2nd position. There's got to be something, somewhere, that Modify ePub is seeing that tells it to move that file to some location regardless of what the spine says. But, darned if I can find it.

[JSWolf]

Originally Posted by enuddleyarbl

Except if I change the order in the spine so the jacket is in the 2nd position, Modify ePub puts it back (in some books) to the 3rd position. In most books, though, it'll put the jacket back into the 2nd position. There's got to be something, somewhere, that Modify ePub is seeing that tells it to move that file to some location regardless of what the spine says. But, darned if I can find it.

I don't know. I don't like jackets. I don't actually need it as the description is easily to pull up if I want it.

[BetterRed]

FWIW: Modify has an option to put the 'jacket' at the back of the book. That option may have been added at my request, if not I certainly welcomed it.

BR

[enuddleyarbl]

Just sticking various of Modify ePub's modules into Notepad++, I think I was able to find the issue. It looks like this is handled in add_replace_jacket and is_cover_or_title_id of jacket.py:

...
    # Next add it to the spine. We want it at the start of the book, but
    # after the Calibre titlepage and cover image.
    # TODO: Might want to make this a bit more bulletproof by looking at the guide etc.

    insert_pos = 1
    spine_items = list(container.get_spine_items())
    while insert_pos < len(spine_items):
        spine_id = spine_items[insert_pos].get('id').lower()
        if not is_cover_or_title_id(spine_id):
            break
        insert_pos += 1

    if jacket_end_book:
        insert_pos = -1
    container.add_to_spine(id, index=insert_pos)
    container.set(container.opf_name, container.opf)
    return True

def is_cover_or_title_id(spine_id):
    return spine_id.startswith('cvi') or spine_id.startswith('cover') or spine_id.startswith('titlepage') or spine_id.startswith('tp')

So, starting at the beginning of the spine, it starts looking for a place just after the Calibre cover and titlepage for the jacket. It defines those pages as ones with ids starting with "cvi", "cover", "titlepage" or "tp". And that last one seems to be the issue. Even though I change the name of the existing title page to "tpage.xhtml", I don't change the id in the manifest. So, whatever the author/publisher assigned it as an id is what's being checked. In this book's case, the id is "tp". So, Modify ePub goes right by it and inserts the jacket at the next position. It looks like most of the time, the id of that title page is NOT "tp" (or starting with tp -- for instance, in one of my multitude (usual) of books where the jacket gets put into the 2nd position, the tpage.xhtml file has an id of "title"). So, the jacket gets put just before that page instead of just after it.

I don't see how Modify ePub could change its behavior to handle all cases (it mentions a TODO of checking the guide -- but there IS no guide in this particular book), so it looks like the work-around (assuming this bothers me enough to do it) is to change the id of that tpage.xhtml file to something not starting in "tp" in both the manifest and the spine.

QED. At least I understand what I'm seeing, now.

[enuddleyarbl]

@kiwidude: I've been pounding my head against a wall trying to set up VS Code to work with Calibre and plugins. I just found your Contributing page for your Github repository:

https://github.com/kiwidude68/calibr...ONTRIBUTING.md

and I'd like to thank you for that. That should help me tremendously in getting the environment set up.

[kiwidude]

Release Notes
https://github.com/kiwidude68/calibr...fy_epub-v1.8.2

An important fix in this one to handle badly named html files in the manifest such as with spaces/brackets in them. Somewhere along the way things got messed up (or maybe always broken), which meant if you did something like "Remove unmanifested files" then these poorly named files would get removed even though they do exist in the epub.

[kiwidude]

Release Notes
https://github.com/kiwidude68/calibr...fy_epub-v1.8.3