Non-Linear TOC

[howardgo]

It appears that KOReader does not handle a non-linear TOC very well. Both Analog and Asimov's magazines have recently changed (finally) their digital subscriptions over to epub and pdf files available outside of a particular vendor's application. The epub files they send have the content in the same order as the print version and the TOC matches the print as well. However, the TOC is grouped by section or length of story and is not sequential. This means that the chapter title and length are all wrong in KOReader, as well as the chapter ticks in the progress bar.



As you can see in the photo, in KOReader it shows that I am on a flash fiction story entitled "The Queen of Copies Meets Her Match" when I am actually on the top level section page entitled Poetry.

Is there any way to accommodate this unusual TOC? Perhaps leverage the file order in the spine of the .opf file?

I can always use Calibre to create a replacement TOC that is sequential, but I'm hoping there is a way for KOReader to handle this. The Calibre reader seems to handle it alright. In the screenshot below I am on the same page as the KOReader photo. Calibre is showing me in the correct section of the TOC. The chapter lengths and titles also appear correctly in the Calibre reader.

[NiLuJe]

Hard to tell you much without an actual sample ;o).

(Also, this'll probably get better coverage on GitHub)

[Quoth]

Though in theory a non-linear TOC is possible, it's a stupid decision by the formatter/designer.
Compare a paper book. The Contents page at the start is always linear. If you want the content grouped in some non-linear way you put specialized indexes.

So the system TOC should really be strictly linear, even if non-linear works on something. The "grouped by" "contents" is a special index and thus should be inline pages at the start or end of the book and get an entry in the system TOC.

I think many physical eink only support linear, though a Kindle isn't epub, you usually upload epub file to KDP.

All kinds of mad things work in the Calibre viewer that shouldn't be in widely compatible ebooks, because it's a custom use of a web browser. I only use it to check links and that the (system) TOC is matching the original Wordprocessor inline automatically built contents page, which unsurprisingly is always linear!

[Jellby]

What is relevant is what the format specification says, regardless of what is supported by other readers or what is customary in paper books. I'm not fully updated with respect to ePub 3, but from what I understand of the NCX specification (the only TOC format supported in ePub 2), it specifically allows for out-of-order TOC items, provided their "playOrder" attributes are consecutive and ordered in reading progression.

[Quoth]

Yes, but just because something is in a specification doesn't mean it's a good idea to use. There are loads of things in epub3 that shouldn't be in a "real" ebook.

Out-of-order lists by some other criterion isn't a table of contents, even if a spec allows it. It should be a special index page. The TOC should then include that and be sequential, Anything else, even in a spec, makes not sense.

And also any such illogical TOC can't be automatically built. It would have to be manually edited everytime the source of the ebook is changed in structure.