Backward-compatible EPUB 3 files with Sigil in 4 steps?

[zonker]

Hi, I'm writing an ebook template with Sigil and I'd like it could be a backward compatible epub 3 file.

Working with Sigil is it enough change the following things?

• put version="3.0" instead of 2.0 inside <package>
• insert a Navigation document
• indicate cover in <manifest>:

  <item id="cover-image" properties="cover-image" href="Images/front_cover.jpg" media-type="image/jpeg"/>

• add “dc:terms modified” metadata

something else? should be this fully compatible with old ereaders?

[DiapDealer]

You'd have to do all that outside of Sigil. Most of those changes will not survive a Sigil "save."

But I'm confused; ePub2 will already be fully compatible with old ereaders. And any ePub3 reader worth it's salt will also be able to read ePub2s.

Don't get me wrong, I'm perfectly OK with people creating ePub3s, but what's the point of jamming plain-jane ePub2s into a quick & dirty ePub3 container in the first place? It it a submission requirement or something?

EDIT: calibre's book-edit should allow you to save those kinds of changes.

[JSWolf]

Originally Posted by DiapDealer

You'd have to do all that outside of Sigil. Most of those changes will not survive a Sigil "save."

But I'm confused; ePub2 will already be fully compatible with old ereaders. And any ePub3 reader worth it's salt will also be able to read ePub2s.

Don't get me wrong, I'm perfectly OK with people creating ePub3s, but what's the point of jamming plain-jane ePub2s into a quick & dirty ePub3 container in the first place?

There is no good reason to make an ePub 3 if the ePub is not using any of the ePub 3 specific features. If the ePub is using ePub 3 features, it's going to have a lonely life upon the virtual shelf as most ePub readers don't do ePub 3.

I have seen some publisher eBooks using an ePub 3 container which only makes things more difficult as you change something and it could break the ePub. I've not seen any of these ePub using any ePub 3 specific features.

[zonker]

thanks

but a navigation document don't look better than the toc.ncx in iBook for example?

however I didn't write it yet, but the rest survives Sigil "save" up to now

(this is my source: http://toc.oreilly.com/2013/02/oreil...to-epub-3.html)

[DiapDealer]

Also: whether or not your ePub3 is "fully" backward compatible with epub2 renderers or not will depend heavily on the epub2 renderer itself (and the markup/css you've chosen to include in your ePub).

EDIT: yes, I see now that those changes will survive a Sigil change (just not a validation). So perhaps it will work for your wish to submit epubs to iBooks that use a nav document.