Upgrading to EPUB 3 is not a trivial undertaking
We at O’Reilly are very pleased to announce that we have officially upgraded to EPUB 3, and ebook bundles purchased from oreilly.com will now include EPUB 3 files, in addition to Mobi and PDF files. All O’Reilly ebooks released in 2013 are now available in EPUB 3 format, and in the coming weeks, we will be updating and rereleasing our backlist ebooks in EPUB 3 as well.
But while we’re excited to share this news, this article is not merely a press release. The decision of when and how to upgrade to EPUB 3 has been challenging for many in the publishing community, and it has been a long journey for O’Reilly as well. I’d like to talk more about why we chose to take this step now, what additional value we believe EPUB 3 provides to our customers, and the challenges and tradeoffs we’ve tackled in making our EPUBs backward compatible with EPUB 2 platforms.
Despite a huge leap forward there's still plenty of room for improvement
2012 was a good year for Kindle developers. With the unveiling of the first-generation Fire tablet in late 2011 and the release of the KF8 Mobi format in early 2012, designing beautiful ebooks for the Kindle platform became a reality. KF8 introduced a fixed-layout specification for Kindle Fire, which opened the door to graphically rich titles—children’s books, graphic novels—in Mobi format. KF8 also greatly increased CSS2 compliance for standard reflowable ebooks, implemented a handful of CSS3 features (text shadow, rounded borders), and added support for embedded fonts. The subsequent rollout of KF8 to Kindle eInk readers running firmware 3.4 (including the new Kindle Paperwhite) and KF8’s support for @media queries to enable fallback styling for non-KF8 devices helped to increase rendering parity within the diverse Kindle ecosystem.
How to mimic flowing text in a non-reflowable format
Q: In a traditional printed book, if a paragraph has not finished when the end of the page is reached, the entire paragraph will be justified. However the [CSS] command ‘text align last’ does not seem to be honoured in the last paragraph of the page in fixed layout for the iPad…What seems to happen is that in [InDesign CS6] it ‘looks’ justified but it doesn’t make it through to the epub version and there is a small gap at the end of the line. If you add text it goes on to a new line. I tried adding whitespace but that didn’t seem to be accepted…Is the problem with ibooks? Is there any workaround?
A: When you load a standard EPUB file into iBooks, the application automatically paginates the HTML content based on screen size and settings set by the user (font and font size). Content flows from page to page, and if a paragraph spans a page break, text alignment will be consistent on both pages.
Fixed-layout EPUBs differ from standard EPUBs in that it is the ebook designer who sets the pagination of the book, not the iBooks application. Each XHTML document in a fixed-layout EPUB file corresponds to a distinct page in the book, and no content is flowed from one page to the next.
If you want to mimic a text flow from page to page in a fixed-layout EPUB, you’ll need to split the text between two separate HTML documents. This poses a challenge if you want your text to be justified, because the text-align: justify CSS property does not stretch the final line of a paragraph to the full text-column width.
The good news is that CSS3 offers a solution to this very problem: the text-align-last property, which allows you to indicate how the final line of a text block is aligned. text-align-last: justify specifies that the final line should be fully justified, and span the full text column width.
The bad news about this good news is that text-align-last is not yet fully honored across all major Web browsers. It is supported in Mozilla-based browsers (Firefox), but is not supported in the Webkit engine, which powers Safari, Chrome, and—sadly—the iBooks ereader. Neither text-align-last nor the WebKit-specific -webkit-text-align-last, nor the EPUB3-specific -epub-text-align-last will produce the desired effect in the iBooks reader.
But some more good news for the intrepid and patient is there’s a hack-y HTML/CSS workaround that can achieve the effect of text-align-last: justify in iBooks (your mileage may vary on other ereader platforms).
Tweak word spacing using CSS
The old-school (dating all the way back to CSS1) word-spacing property allows you to designate a specific amount of space to place in between words. The following example uses word-spacing: 7px to specify that the last seven words on the page should have seven pixels of whitespace between them:
<p>Everywhere there are mysteries. And the most ancient man-made wonders of all are the stone monuments erected by our Neolithic and Early bronze Age ancestors between 4000 and 1500BC - or, if it is less difficult to visualize in this way, between 140 and 240 generations ago. Little England (and smaller Scotland and Wales) are rich in these megalithic structures. Archaeologists tell us that more than a thousand chambered tombs and some 700 stone circles have resisted the smoothing iron of wind and rain, the teeth of the plough, the <span style="word-spacing: 7px">grasping hands of wave upon wave of</span></p>
And here’s a screenshot illustrating how this text renders in iBooks.
The main benefit of this approach is that it gives you fine-grained control over the whitespace in a paragraph. The downside is that it can require a fair amount of trial and error to determine the proper word-spacing values to achieve the desired justification effect. If you do decide to use this method, and have a paid iTunes Connect ebooks account, I highly recommend using Apple’s Book Proofer tool, as it eliminates much of the hassle involved in syncing EPUB files between your computer and your iPad/iPhone/iPod.
Add a painting tool to a book with HTML5's Canvas.
This excerpt from "HTML5 for Publishers" shows how a simple finger painting canvas can be added to an HTML5-based children's book