Missing Cover Thumbnail in TOC (Apple Books)

[fkjal]

Currently creating an ePub from scratch and couldn't seem to find which field/xhtml/code links the imported cover (jpg) successfully to the thumbnail preview in the Table of Contents.

I'm using an iPad and am previewing/reading the ePub on Apple Books. As you could see below, when I click the TOC part, it only displays the default blank template (see attachment). Any help would be greatly appreciated.

[DiapDealer]

A thumbnail preview in the toc is not a standard epub feature. Whatever Apple is using to make that appear is likely proprietary.

Did you define the standard epub cover metadata? If not, it may be a simple as that.

[fkjal]

Originally Posted by DiapDealer

A thumbnail preview in the toc is not a standard epub feature. Whatever Apple is using to make that appear is likely proprietary.

Did you define the standard epub cover metadata? If not, it may be a simple as that.

On Sigil, I imported the image into the file, made it as the default cover image (ticked that on right-click), made a CoverImage.xhtml page, and looked for all "cover.jpg" mentions across HTML just to see if their encoding & directories all check out.

Apart from that, I'm not exactly sure where I can edit the metadata for this. Do you have other ideas for this one?

[DiapDealer]

I've no idea, really. If you've set all the standard epub cover image/page metadata (as it appears you have), whatever Apple is using to display the cover image thumbnail in the toc is likely proprietary xml metadata. I've never encountered it (or the Apple Books toc thumbnail feature) before.

[theducks]

Originally Posted by fkjal

On Sigil, I imported the image into the file, made it as the default cover image (ticked that on right-click), made a CoverImage.xhtml page, and looked for all "cover.jpg" mentions across HTML just to see if their encoding & directories all check out.

Apart from that, I'm not exactly sure where I can edit the metadata for this. Do you have other ideas for this one?

Both the Image and the page need to be marked (semantics) as cover in a normal EPUB. (the filename does not need to include the word cover. That is for humans)

[KevinH]

And the cover images for each epub are cached by Book.app (iBooks) the first time an epub with that unique identifer is imported into Books.app.

So delete that epub completely from Books.app. Fix the metadata to properly identify the cover xhtml file and fix the manifest properties to properly identify the cover image itself.

Once properly set, the cover should appear on your Desktop, and will appear after adding that fixed ebook to Books.app.

[AlanHK]

Originally Posted by KevinH

And the cover images for each epub are cached by Book.app (iBooks) the first time an epub with that unique identifer is imported into Books.app.

So delete that epub completely from Books.app. Fix the metadata to properly identify the cover xhtml file and fix the manifest properties to properly identify the cover image itself.

It's not so easy to completely delete from Books app. It retains the metadata and if you import a new version of the book, it may try to use the original metadata.

E.g. it will bookmark the last page you were on and try to reopen on that page. If you have renamed the files in the ePub, it can crash when it can't find it. And other weirdness. Apple's way of punishing you for not buying from them; it will just fail rather than use a sane fallback.

Always use epub3, with epub2 it will never update things like the TOC from new versions.

If it appears stuck with old metadata, change the unique ID of the new version.