Epub files created on Sigil close after cover on Kobo

[romanf]

Can you please verify that the attached scrambled epub also exhibits the same problem

It does.

FYI, scrambling removes the DOCTYPE because scrambling runs under calibre's rules/conventions and calibre never creates epubs with DOCTYPE.

That's useful info, thanks!

The Kobo Adobe renderer does not seem to like the 3 style rules containing the 'vh' unit

This is it! I recently started to use the percentual 'vh' instead of the fixed 'em' to make the chapters top margin more flexible. I just tested reverting back to 'em' and it works.

The thing is, I have other files with the 'vh' unit that work.
For example:

.fr{
display:flex;
flex-direction:column;
justify-content:space-between;
height:90vh;}

and

h1{ text-align: center; font-weight: normal; font-size: 1.2em; margin: 3.0em 0 30vh; font-family: "Copperplate", serif; letter-spacing: 2px; }

Also when declared outside the css file:

<p style="text-align: right; text-indent: 0px; margin-top:20vh"><i>“Somos débeis, mas ao nosso sinal</i>,</p>

In all this cases the file works properly.

Any thoughts on that?

Anyway, thanks for the great help!

[jackie_w]

Originally Posted by romanf

In all this cases the file works properly.

Any thoughts on that?

Anyway, thanks for the great help!

The only thoughts I have on the above CSS style is that it's far too new-fangled for me to assume it will work in all the reading apps I might want to use (particularly on my Android phone) I'm pretty risk-averse with CSS properties.

On a Kobo the newer-style CSS may have a better chance of working as kepub than epub, but I'm not sure whether anyone has ever done a detailed analysis of exactly what works and what doesn't.

[JSWolf]

I don't use vh because I read mostly with RMSDK on Kobo and it doesn't work.

.fr {
  display:flex;
  flex-direction:column;
  justify-content:space-between;
  height:90vh;
}

I'm not 100% sure, but I would think that the class "fr" will not work in RMSDK as none of that is compatible.

Question I have is what in the .fr class will work with KePub other then the height line?

[romanf]

I can't tell right now if it works or not, but at least it doesn't crash like in the h1 example.
I'm ok with it not working if there's no support for it, but at least it should display the file with or without supported css properties.

[romanf]

The only thoughts I have on the above CSS style is that it's far too new-fangled for me to assume it will work in all the reading apps I might want to use

You might be right, but the results are quite better this way

[JSWolf]

Originally Posted by romanf

I can't tell right now if it works or not, but at least it doesn't crash like in the h1 example.
I'm ok with it not working if there's no support for it, but at least it should display the file with or without supported css properties.

But what is "fr" supposed to do in this ePub?

[romanf]

But what is "fr" supposed to do in this ePub?

Distribute 3 divs evenly on the vertical space.
Autor name on top, title in the middle, and editor name in the bottom.

[jackie_w]

Originally Posted by romanf

You might be right, but the results are quite better this way

Out of interest, which eink devices and phone reading apps does your CSS3 work well on?

[JSWolf]

Originally Posted by romanf

I can't tell right now if it works or not, but at least it doesn't crash like in the h1 example.
I'm ok with it not working if there's no support for it, but at least it should display the file with or without supported css properties.

But if the CSS is not supported, what is it you are missing or what's not displaying as it should? Also, if RMSDK finds an error in the CSS it will ignore the entire CSS. The error doesn't have to be an error. It could be some ePub 3 code that RMSDK thinks is an error.

[romanf]

But what is "fr" supposed to do in this ePub?

Distribute the divs evenly in the vertical space. In this case Author name, book title, and editor name.

Out of interest, which eink devices and phone reading apps does your CSS3 work well on?

This .fr class isn't giving me any problems, only the 'margin' property on the h1 class, apparently. I tested it on Moon+Reader, Kobo App, Google play books, and on Windows: ADE, Calibre Reader, Kobo Reader.
The one with the vh on the h1 class crashes only on the Kobo e-reader. The other files don't crash, but I'm not sure they display as intended on every device/app.

But if the CSS is not supported, what is it you are missing or what's not displaying as it should?

Im sorry if I'm being ignorant here, I'm just an amateur. But as far as I know, css is just an appearance file. If it's not supported, it should at the very least display the plain text. But as stated in the beginning of this thread, in some cases it just opens the cover and then just closes, marking the book as finished.

I'm sorry if this is too confusing. Thanks for helping me identify the problem! I'm just trying to deepen my understanding of this issue.

[JSWolf]

Have you converted this eBook to KePub with Calibre using the KoboTouchExtended driver?

[DNSB]

For what it's worth, removing the vh properties and replacing them with em allows the scrambled ebook to display on my Sage using the RMSDK renderer. Converting original epub to kepub either by a simple rename (not recommended) or by using kepubify or calibre with the KoboTouchExtended driver allows the resultant kepub.epub to work happily using the WebKit based renderer on my Kobo Sage.

BTW, when I tested the original scrambled files with Sigil and it's renderer options, Thorium and several other apps, the display was not consistent between them. The vh property worked on some and on others, appeared to be disregarded with the h1 and h2 being displayed at the top of the viewport while the h3 did maintain it's margins. One antique program was also unhappy with the shortcut margins (it needs either margin ww,xx,yy,zz or using the margin-top, bottom, left and right forms)

Please note that simple renaming is a quick and dirty hack for testing and is not recommended by Kobo as it can and will cause text selection and other issues. Either kepubify or using the KoboTouchExtended driver will modify the original epub to more closely match a Kobo supplied kepub.

And also remember that like all renderers, Kobo's renderers do not implement the full epub3.x specification. There a test page (www.epubtest.org) where the compliance of various renderers were rated though I'm uncertain as to when the last updates to the site were made.