Incorporating NCX file into Epub3 book for backward compatibility

[tbrosz]

I am getting requests for Epub3 files that still have an NCX file for backward compatibility. I am converting from original .docx files, with a simple hyperlink TOC added for in-book use. The converter uses "Heading1" and other signals to build the actual Epub3 TOC in the nav.xhtml file.

While the Epub3 conversion works well except for some minor after-conversion .xhtml edits needed, there doesn't seem to be any conversion option to seamlessly add an additional NCX file during the conversion process.

I can tack an NCX file into the book using the TOC editor, but EpubCheck 4.1.1 has problems with it, and it reads in the Calibre viewer as two consecutive TOCs.

Could the Calibre converter maybe add an option somewhere for "add NCX file to Epub3 for backward compatibility?" Or is there already one somewhere I've missed, like a plug-in?

[jackie_w]

Deleted. Sorry... I missed the bit where you said you'd already tried the calibre TOC Editor.

I just tried adding an NCX to an epub3 using the TOC Editor. EpubCheck 4.1.1 doesn't have any problems with it and neither does the calibre Viewer.

[BetterRed]

@tbrosz - I was about to suggest trying the ToC editor in Sigil, but I see jackie's updated her post.

But it might be worth a try if you can't get calibre to do it.

BR

[tbrosz]

Originally Posted by jackie_w

Deleted. Sorry... I missed the bit where you said you'd already tried the calibre TOC Editor.

I just tried adding an NCX to an epub3 using the TOC Editor. EpubCheck 4.1.1 doesn't have any problems with it and neither does the calibre Viewer.

Which specific box did you click on the "Generate TOC" commands?

[tbrosz]

Originally Posted by BetterRed

@tbrosz - I was about to suggest trying the ToC editor in Sigil, but I see jackie's updated her post.

But it might be worth a try if you can't get calibre to do it.

BR

When I opened the file in Sigil, it actually automatically added an NCX file. Calibre didn't seem to like it, though, when I opened it over there again. I'm still exploring this.

[jackie_w]

Originally Posted by tbrosz

Which specific box did you click on the "Generate TOC" commands?

I think you're over-complicating it If you open the TOC of the epub3-with-no-NCX with the calibre TOC Editor then you don't need to 'Generate' anything. Just immediately re-save it by pressing the 'OK' button. Calibre will auto-magically create an NCX which matches the NAV and do any necessary housekeeping (e.g. OPF update).

[tbrosz]

Originally Posted by jackie_w

I think you're over-complicating it If you open the TOC of the epub3-with-no-NCX with the calibre TOC Editor then you don't need to 'Generate' anything. Just immediately re-save it by pressing the 'OK' button. Calibre will auto-magically create an NCX which matches the NAV and do any necessary housekeeping (e.g. OPF update).

Holy smoking flatfish. That worked.

I have an NCX file, it passes the online Validator check, and it reads normally in the viewer.

Talk about a hidden feature! I spent hours sweeping the menus for a button or a conversion setting to specifically do this.

I will run this through to the publisher and see if it works for them. You are my hero of the day. How did you find this out in the first place?

[KevinH]

FWIW, Sigil will createan empty NCX for any epub3 without one, and there is a single epub3 menu "Generate NCX from Nav" thay you can use to populate that empty NCX right before saving if you so desire.

[jackie_w]

Originally Posted by tbrosz

How did you find this out in the first place?

Mostly just by using the calibre Editor to edit/cleanup an awful lot of personal epubs. Glad it worked for you

[ydonse]

Awesome, it worked for me as well.
However i would like Calibre to generate it when I convert a docx to epub through cli. Do anyone know if it is possible ?